Inheritance of colors in cats. Genetics of cat colors. Cameo, red and cream-silver tabbies

Two long-haired parents cannot produce a short-haired kitten;
Only the parents' colors determine the color of the kitten. The colors of other cats present in the pedigree do not have a direct effect on the color of the kitten;
A cat kitten always gets its color from its mother;
A cat kitten always gets its color, which is the color of its father and mother;
To obtain a genetically red or genetically cream-colored kitten from a cat's litter, it is necessary that the father be genetically red or genetically cream-colored, and the mother must also have a red or cream-colored genotype;
Dominant characteristics (dominant colors: white, veiled, shaded, smoky, tabby, bicolor) cannot skip a generation. They cannot pass, for example, from grandfather to grandson without manifesting themselves in the father;
A kitten of a dominant color (black, red, tortoiseshell) must have a parent of a dominant color;
Two parents of a recessive color (cream, blue) cannot produce a kitten of a dominant color (black, red, tortoiseshell);
A white kitten must have a white parent;
A kitten with a white undercoat (veiled, shaded, smoky) must have a parent with a white undercoat;
A veiled/shaded kitten must have at least one parent who is either veiled/shaded or tabby;
A veiled/shaded parent can produce a smoky kitten, but a smoky parent cannot produce a veiled/shaded kitten.
A tabby kitten must have at least one parent who is either veiled/shaded or tabby.
All red cats have some degree of tabby. The ability to produce tabby offspring depends on whether the red cat (or tom) is a true tabby, i.e. does it have a tabby or veiled/shaded parent, or is it just a red cat with a pronounced tabby pattern. A red tabby, unless it is a true tabby, cannot produce a tabby offspring of any other color unless it is bred to a true tabby (or a veiled/shaded one):
A brindle tabby kitten must have a brindle tabby parent;
A spotted tabby kitten must have a spotted tabby parent;
Multi-colored individuals (tortie, blue-cream, tortoiseshell and white, blue-cream and white, tortoiseshell, smoky) are almost always cats, but cats can and are sometimes born;
A bicolor kitten must have a bicolor parent;
Two color point parents cannot produce a non-color point kitten;
It is possible to get a color point kitten only if both parents are carriers of the color point gene (even if they themselves are not color points);
If one parent is a color point and the other is a Persian who is not a carrier of the color point gene, there cannot be a single color point kitten in the offspring;

1. Male kittens always get their color from their mother. Male kittens in a litter will always be either the mother's color (or one of the colors in the case where the mother is multicolored) or a diluted form of the mother's color. (see nuances No. 21 and No. 24).
2. A cat kitten receives one color gene from each parent. The color of the cats in the litter will always be either a combination of the colors of the mother and father, or these colors in a diluted (diluted) form. (see No. 21 and No. 24)
3. To obtain a female cat kitten of red or cream color/pattern, the cat must be red or cream color/pattern PLUS the cat must carry red or cream in the genotype. (see No. 21).
4. Only the immediate parents determine the color/pattern of the kitten. The colors of the ancestors do not always affect the color of the kittens. A notable exception is the color point gene, which offspring can carry through several generations (see #21 and #24).
5. The kitten pattern can be inherited from both parents.
6. Dominant characteristics (all dominant colors and patterns, such as shaded, smoke, white, tabby, bicolor, etc.) cannot skip a generation. That is, they cannot pass on to their grandchildren or great-grandchildren without manifesting themselves in their parents.
7. A kitten of a dominant color (black, red, tortoiseshell, etc.) must have a parent of a dominant color (see No. 21).
8. A pair of parents of a recessive color (cream, blue, etc.) cannot produce a kitten of a dominant color (black, red, etc.)
9. Two Color Point parents cannot produce non-Color Point kittens. See #8
10. To get a color point kitten, both parents must carry the color point gene (even if they themselves are not color point).
11. The mating of a color point cat and a non-color point cat (and not carrying the color point gene) cannot produce color point kittens.
12. Tabby (not silver) kitten must have at least one parent who is either shaded or tabby. A silver tabby must have at least one silver tabby parent, either shaded or smoke (see #13).
13. All red cats are tabby to some extent. The birth of tabby kittens depends on whether the red cat (or tom) is a true tabby, i.e. does she have a tabby parent or a shaded one, or is she just a red cat with an outwardly defined pattern. A red tabby that is not a true tabby cannot produce tabby offspring of any other color unless it is bred to a true tabby or a shaded one.
14. A cat with a white undercoat (smoke or shaded) must have a parent with a white undercoat (see #21).
15. Shaded cat A cat must have at least one shaded parent (see #21).
16. A shaded parent can produce smoky offspring, but a smoky parent cannot produce shaded offspring unless bred to a shaded one (see No. 21).
17. A bicolor must have a bicolor parent (see #21).
18. Multi-colored individuals (blue-cream, tortoiseshell, tortoiseshell and white) are almost always cats, but sometimes males can be born (and not always sterile).
19. A white cat must have a white parent.

20. Solid (solid) white cats, both externally white (what we see) and hidden color (those that are not visible, but are “in the soul”) and can give birth to offspring of both white and hidden color/pattern . The hidden color/pattern of a white cat must be determined based on the pedigree and, in order to effective planning colors/patterns of the offspring, offspring from a white cat should be monitored. Interestingly, white kittens may have a small patch of color on the top of their head at birth. This color should be noted as the color that is “hidden” under the white and that the cat can produce in offspring. The coloring of the spots may be visible for several months, but usually disappears as the kitten grows older.
21. The genetics of solid white cats can influence the colors/patterns of the expected kittens; the white parent may hide the color/pattern of the kitten that was desired to be obtained.
22. A short-haired kitten cannot be born from the mating of two long-haired sires.
23. Two classic tabby parents cannot produce a brindle, spotted, or ticked tabby kitten. Ticked tabbies must have ticked tabby parents. A brindle or spotted must have a brindle, spotted, or ticked tabby parent (see No. 21).
24. The dilute (dilut) gene must be present in the genotype of both parents in order to produce offspring of a dilute (dilut) color.
25. The chocolate or lilac gene must be present in the pedigrees of the father and mother in order to produce chocolate or lilac colored offspring.

Elementary rules of cat genetics -

What can and cannot be achieved...

1. Two long-haired parents cannot produce a short-haired kitten.

2. Only the parents' colors determine the color of the kitten. The colors of other cats present in the pedigree do not have a direct effect on the color of the kitten.

3. A cat kitten always gets its color from its mother.

4. A female cat always receives a color that is a combination of the colors of the father and mother.

5. Dominant characteristics (dominant colors, white, veiled, shaded, smoke, tabby, bicolor, etc.) cannot skip a generation. They cannot pass, for example, from grandfather to grandson, without manifesting themselves in the father.

6. A kitten of a dominant color (black, red, tortoiseshell, etc.) must have a parent of a dominant color.

7. Two parents of a recessive color (cream, blue, etc.) cannot produce a kitten of a dominant color (black, red, tortoiseshell, etc.).

MAIN COLORS :
1. Two blue parents will never produce a black kitten.

2. Only purple children are born from two purple parents.
3. Two blacks can give birth to: black, chocolate, blue and lilac

4. Two chocolates will not make black and blue.

5. A black kitten can be born from blue and chocolate parents.

SILVER

1. A veiled/shaded kitten must have at least one parent who is either a veiled/shaded or a silver tabby.

2. A veiled/shaded parent can produce a smoky kitten, but a smoky parent cannot produce a veiled/shaded kitten.

3. Two non-silver parents do not produce silver children (the inhibitor gene I is dominant, if the parents do not have it (that is, both parents ii), where does it come from in children?

But from two silvers a kitten without silver can be born (if both parents are heterozygous, that is, they have Ii).

AGOUTI + TABBY
1. Two solid (plain) cats will not produce a child with a pattern on their fur coat.

2. From solid (non-agouti, monochromatic) and patterned (agouti, tabby) both solid-colored babies and tabbies can be born.
3. From two agouti tabbies, in the case of heterozygosity of both parents, non-agouti (that is, monochromatic) children can be born.
4. From two parents with a marbled pattern, you will get children only with a marbled pattern (the marbled pattern gene appears only in a recessive form).
5. Two spotted parents will produce spotted cats, and may produce children with a marble pattern if both(!) parents are marble carriers.

6. A brindle tabby kitten must have a brindle tabby parent.

7. A spotted tabby kitten must have a spotted tabby parent.

8Dominance of patterns over each other: ticked -> mackerel -> spotted -> marbled.

9 Tabby is not a color, but a type of pattern that can go with any color. All cats are tabbies, but not all agoutis.

BICOLOR AND WHITE
1. Two non-bicolor parents will not produce a bicolor kitten (the white piebald gene - S - dominant).
2. To have a bicolor child, you need at least one bicolor parent.
3. From non-bicolor and solid white parents a bicolor can be born (white covers all the colors underneath, so it’s unknown what’s underneath, what if a bicolor??)

4. A white kitten must have a white parent.

COLOR POINTS
1. Two color points will only produce color points.
2. A color point can be born from a color point and a non-color point, but only if the non-color parent is a carrier of the color gene.

3. Two non-colorpoints can produce a colorpoint only if both of these non-colorpoints are direct carriers of the color gene

TORTIE COLORS

1 Seals are not tortoiseshell. More precisely, they do exist, but they are extremely rare and they are sterile.
2 Correct names: black tortoiseshell (black-red color), chocolate tortoiseshell (chocolate-red color), blue tortoiseshell (blue-cream color), lilac tortoiseshell (lilac-cream color).
3 Tortoiseshell colors with white are called “calico”.
4 Tortoiseshell tabby colors are called "torbies"

5 From a tortoiseshell cat and a non-red/non-cream cat you can get turtle cats, non-tortoiseshell cats, non-red/non-cream cats and red/cream cats. There will be no red/cream female cats.

6 From a tortoiseshell cat and a red/cream cat you can get tortoiseshell cats or red/cream cats and red/cream cats and non-red/non-cream cats.

7 From a non-tortoiseshell cat and a non-red/non-cream cat you will NOT get red/cream/tortoiseshell cats.
8 From a non-tortoiseshell cat and a red/cream cat you will only get tortoiseshell cats and non-red/non-cream cats.

GOLDEN COLORS

Gold Maybe born at mating

— silver+silver, subject to the presence of gold from both manufacturers.

- gold+gold,

Gold+silver(gold carrier)

Gold+brown tabby (gold carrier)

Gold can not be born

From two brown tabby colors

- if one producer is gold and the other is silver, brown tabby, solid (not carriers of golden color),

then in the first generation gold is not born, but kittens with a warmer undercoat are born.

— two golden colors cannot produce silver, but there can be gold and brown tabby.

- gold + silver (carrier of gold) = gold, silver, Brown tabby are born

Cat to human age ratio

Table of probable colors of kittens

Our Maine Coon cattery deals mainly with merle, ticked and solid colors: all variations of black, blue and red. Although there are exceptions when type prevails over color.

Let's understand what a genotype and phenotype are and how they differ, what dominant and recessive genes are and how they are correctly designated, and, finally, what is a rather important concept in genetics like an allele. So, let's begin.

The genetic information embedded in the body is called a genotype, and its external manifestation is what we see - a phenotype. A genotype is a set of characteristics transmitted to a descendant by ancestors. There are two types of genes: dominant - the main one, it always appears in the phenotype, it is visible. Always indicated with a capital letter. For example "A". And recessive is the one that obeys. Despite its presence in the genotype, it may not appear in the phenotype. Recessive genes (i.e., the trait they determine) may not appear in one or many generations until two identical recessive genes from each parent occur. Indicated by a small letter. For example "a". A cat that has two identical genes (dominant, such as AA, or recessive, such as aa) will be called homozygous. And a cat that contains both a dominant and a recessive gene (Aa) is called a heterozygote. A dominant gene is always externally manifested by a corresponding sign, even if the dominant gene “works” without a partner. But not all genes are absolutely dominant or recessive. In other words, some are more dominant than others and vice versa. For example, some factors that determine coat color may be dominant, but still not appear outwardly unless they are supported by other genes, sometimes even recessive ones. Some external characteristics may be “dominant” in some breeds and “recessive” in others. In genetics, the concept of allele is accepted. An allele is one of the forms of the same gene that determines one of the options for the development of a trait. This word will denote the trait for which the gene is “responsible.” The color of the coat depends on the type of a very complex substance in its composition - the pigment melanin. There are only four pigments. Two basic ones are eumelanin (it forms black (melanin itself), brown and cinnamon colors) and pheomelanin (red color options), which exist in the form of pigment grains (mylanosomes) of various shapes. Melanin grains are quite large and packed tightly into the fur, which is why, as you have probably noticed, the fur of black animals is quite harsh.

In specific cases, we often talk about a genotype, meaning not the entire genome, but some individual gene or group of genes. The phenotype is determined by the genotype primarily due to the relationship of the alleles that make up the genotype. Each gene found in animals or humans receives its own name, and to designate the alleles of this gene, one or two initial letters of its English name are used (for example, White - a dominant white color, whose allele can be designated as W).

The colors of cats are very diverse. Some cats are uniformly colored - these are the so-called solid colors or solids. Others have a pattern - stripes or spots throughout the body. This pattern is called tabby.

Tabby is divided into:

Mackerel tabby (tiger or mackerel) - pattern in the form of thin transverse stripes. Formed by the T gene. Stripes will appear only when the gene is dominant.
Classic tabby (marble) - wide spiral or ring stripes on the sides in the form of butterfly wings, reminiscent of marble stains. It is formed by the most recessive form of the tabby gene - tt with the superscript “c”. Those. merle kittens can only be born from parents with merle color or having this color in their genetics.
Spotted tabby (spotted) - has scattered spots throughout the body, ideally clear and not merging. Formed with the help of the main tabby genes and the polygene complex. And this gene also only has a recessive form. Spotted and brindle colors often form multiple transitional forms, and all these variants are always classified as spotted color, because the stripes tend to “tear” as the animal grows older. Therefore, spotted is the most common color among patterned cats. Spotted kittens can be born in a case similar to the merle color.
Ticked tabby - This pattern looks like small specks or ripples on the coat. It is formed by the Ta gene, the most dominant of all patterned colors. In the homozygous manifestation, the ticked color lacks not only stripes on the body, but also on the tail, paws and chest; in the heterozygous manifestation, the body is ticked without a pattern, and there are stripes on the points

Solid colors:

Single color or otherwise solid color, when a cat’s coat color is the same throughout its entire body. Most solid colors are developed by suppressing recessive tabby genes. Sometimes the pattern is not completely suppressed, then a vague shadow tabby is visible. Red and cream colors cannot effectively suppress tabbies, so the pattern on such animals, to a greater or lesser extent, is always present. The monochromatic white color is obtained as a result of the action of different genes that completely suppress the color.

Smoky color (smoke)- This is a single-color version of silver tabbies, when only the ends of the coat are colored.

Colorpoint- this group of colors is characterized by a light body and darker paws, muzzle, ears and tail.

Bi-colors- on a white background there are painted spots of different colors.

Harlequin- mostly white with a few large spots of color.

Van- All white with color on the head and tail.

With white gloves (mitted)- white slippers on the feet.

With white medallion (locket) - White spot on the chest.

With white buttons- one or more small white spots.

Tuxedo (tuxedo)- with white paws and chest. May have a little white on the head.

Tortoiseshell color - the cat's fur is colored in combinations of black and red, as well as for lightened colors - blue and cream. No two “turtles” are alike - they all have a unique individual pattern. Cats with this color are usually female, since this color is a consequence of incomplete dominance of a sex-linked gene. But there is a rare exception; cats with this color are usually infertile.

When crossing spotted cats with each other, they always produce kittens only with the same pattern and never brindle. There are also no known cases of spotted kittens appearing in merle-colored couples. Between the brindle and spotted colors, all transitional degrees are observed - from stripes broken in several places to almost round spots. There are also known individuals that have 2-3 stripes on the front of the body combined with spots on the back. This could be explained by the intermediate manifestation of the T and tsp alleles. It is interesting that out of hundreds of cats with intermediate brindle-spotted colors, there are literally only a few known with a broken marble pattern!

It is generally accepted that the patterned color is the original color of wild, undomesticated cats. Wild cats are predators; in order to track down prey, they needed to camouflage themselves into their environment. But how many colors are there in the cat color palette? Black, blue, chocolate, brown, cinnamon, lilac, beige, red (depending on the intensity from light red to brick red), cream, yellow - that’s probably all. White color in the proper sense is not a color - it is “uncolored”, the absence of a pigment that creates a particular color.

There are even fewer pigments in the cat world than colors; there are only four - two basic (black eumelanin and yellow pheomelanin) and two derivatives of black - brown and cinnamon. To understand how so many colors of a cat's coat are formed and how the color of each specific cat is genetically determined, we will have to consider the entire process of color formation - pigmentogenesis.

This process begins at the embryonic stage. At very early stages of development, the germ of future pigment cells is secreted in the area of the neural tube. They themselves cannot yet produce pigment; to do this they need to undergo a number of changes.

First of all, they must take on a spindle-shaped shape suitable for migration. These cells migrate first to the center of pigmentation, and from there to the hair follicles. The location of the centers of pigmentation is clearly visible from the position of the colored spots on the body of cats of the so-called Van color and harlequin color: these are primarily spots on the crown and at the root of the tail, as well as on the back and withers. They indicate the position of the centers of pigmentation.

In order for propigment cells to turn into full-fledged, pigment-producing cells (such cells are called melanocytes), they must have time to penetrate the hair follicle (follicle) before its final formation. The combination of the speed of these processes - the movement of progenitor cells and the formation hair follicles determines how colored the cat will be and whether it will retain white spots.

Loci responsible for color.

Locus A "agouti" - (agouti). The dominant gene of the locus is responsible for the distribution of pigments along the length of the cat's hair and body. The pigments eumelanin and pheomelanin form alternating stripes on each hair, the so-called “ticking” - mixed colors of black (or its derivatives) and yellow. Cats with agouti colors are characterized by a light marking in the shape of a thumbprint. human hand on the back of the ear, as well as a pink or brick-red nose, bordered by a narrow dark stripe.
A - promotes the formation wild color.
The recessive allele of this locus is called a - “not agouti”, and ensures a uniform color of the hairs - specifically the hairs, but not necessarily the cat as a whole. That is, a cat with the aa genotype can be black, chocolate, cream, or even have a blue point color - depending on which alleles will be included in other gene loci responsible for color. Naturally, in cats with agouti color, the color of the stripes on the hair also depends on the allelic state of the same genes - stripes can alternate between black and yellow, blue and yellowish, brick and light red, and so on.

Locus B (Blask).
Locus B (Blac) is responsible for the normal formation of black pigment.
B - black color.
Under the influence of the b allele, the pigment oxidizes - it turns brown (chocolate).
Black color completely dominates over brown, and in brown there is incomplete dominance of the b allele over b1, b1 is light brown, the so-called cinnamon color.
. In cats, brown color is much less common than black, and it is practically absent in natural populations. But -B- dominant gene suppresses the action of the -b- recessive gene. Homozygotes and heterozygotes of cats with the B locus are black in color, while homozygotes for the b locus and heterozygotes of bbl are chocolate in color. Kittens inherit one chromosome from each parent. The bl gene oxidizes the pigment even more, resulting in a light, warm shade of brown called “cinnamon.”

Locus C (Color) is a series of albino alleles.

C - ensures normal synthesis of pigments.
cch - silver color. There is a group of alleles at this locus that causes uneven coloring on a cat's body. Such animals have a dark muzzle, ears, limbs and tail, and a much lighter body. These colors result from the presence of a temperature-sensitive form of tyrosinase, which is involved in the synthesis of melanin. At normal body temperature, the activity of this form of tyrosinase is sharply reduced, which leads to lightening of the color. The reduced temperature of the limbs, tail, muzzle and ears promotes the activation of the enzyme and triggers normal melanin synthesis, which ensures the development of the typical “Siamese” color. Experiments have shown that raising Siamese kittens in the cold leads to the formation of a solid dark color, and at elevated temperatures - a light color. This group includes two alleles cb and cs.
cb - Burmese color. Homozygous cbcb animals are dark brown and dark sepia in color, gradually becoming lighter towards the belly. The head, paws and tail of such animals are much darker.
cs - Siamese color. Point coat color. Homozygotes csсs have a body color the color of baked milk or lighter, as well as a dark muzzle, paws and tail. The eyes are bright blue.
ca - blue-eyed albino. Cats of the Sasa genotype have a white coat and pale blue iris.
c - albino with pink eyes. Its homozygotes also have a white coat color, but the iris is colorless (pink).
Allele C is completely dominant over all other alleles of the locus. Intermediate dominance is observed between the cs and cb alleles. Csсb heterozygotes are called Tonkinese and have a color intermediate between Siamese and Burmese and turquoise eyes.
The ca and c alleles are recessive to all higher-level alleles, but how they interact with each other is unknown, since they are extremely rare.

Locus D (Dense pigmentation)
Locus D - is responsible for enhancing or lightening the pigment.
D - full intensity pigmentation.
d - dilution of pigmentation, and, consequently, color.
The D allele makes the color rich and allows the pigment to be densely distributed in the fur: cats will be black or red. Homozygous for the d allele have a lightened color: blue, cream, golden. Wild tabby cats have a lighter color while maintaining a warm yellowish tone. Due to the gluing of pigment granules, the uniformity of their entry into the growing hair is disrupted, which leads to an accumulation of granule mass in some areas and a deficiency in others.

Locus I (Melanin inhibitor). Currently, one mutant allele is known at this locus.
I - this allele promotes the accumulation of pigment granules at the end of the hair. At the base of the hair, the amount of accumulated pigment is minimal, which looks like complete bleaching of the hair roots. This distribution of pigment throughout the hair is called tipping.
The effect of this allele can be observed mainly on long hair. The manifestation of the effect of allele I depends on the alleles of other loci. Thus, in cats homozygous for a, the effect of allele I is manifested in the appearance of a light or white undercoat. These colors are called smoky. In tabby cats, the light areas become almost white, and the dark hair in the area of stripes and spots synthesizes pigment almost completely. This color is called silver. In ginger cats, there is a general weakening of pigmentation and discoloration of the undercoat - a cameo phenotype occurs. However, it has now been proven that the expressiveness of allele I fluctuates very highly, and therefore calling it dominant is not entirely justified. Maximum expression leads to the accumulation of pigment only at the end of the hair by 1/3 of its length in the so-called shaded ones, and by 1/8 in the shaded ones, or, in other words, chinchillas. The color of the ends of the hair depends on the alleles of the B, D and O loci.
i - normal distribution of pigments in the hair.

Locus O (Orange).
The O locus is responsible for “red” colors and leads to the cessation of eumelanin synthesis. O - is located on the X chromosome, that is, color inheritance is sex-linked, so a cat (XY) can carry only -o- or only -O-, i.e. it will be red or black. But there is a rare exception; tortoiseshell cats are usually infertile. In the genotype, cats have two (XX) chromosomes and, accordingly, three color options:
- OO – red
- oo – black
- Oo – tortoiseshell
Small -o is a recessive gene, capital -O is a dominant gene. Moreover, O is also dominant in relation to B, i.e. suppresses black colors. Thus, the inheritance of traits whose genes are located on the X or Y chromosome is called sex-linked. The gene is inherited from mother to son, so a cat that has received the O gene from its mother will definitely be red (of course, if there is no W gene, which suppresses color), and vice versa, a red cat will not give birth to a black cat.
Homozygous cats and homozygous cats have red color.
The effect of the allele is manifested only in the presence of allele A, allele a is epistatic in relation to O. Therefore, the vast majority of ginger cats have a characteristic striped pattern caused by the T locus (tabby).
o - color determined by the basic genetic formula of the animal. It appears as non-red spots on the body of a tortoiseshell cat, which can be black, blue, striped, etc.

Locus P (Pink eyed) - “pink eyes”.
P - color determined by the basic genetic formula of the animal.
p - cats homozygous for this allele have a characteristic lightened reddish-brown fur color and reddish-pink eyes. The mutation is extremely rare, and the nature of inheritance of this trait has not yet been sufficiently studied.

Locus S (Piebald spotting) - white spotting.
Represented by a series of multiple alleles.
S - presence of white spotting.
Sw - Van color - white with two small spots on the head and a colored tail.
Sp - spotted harlequin color.
s - solid color without white spots.
There is no doubt that, in addition to the main alleles of the locus, a large number of modifier genes are involved in the formation of spotted colors, just as it happens in animals of other species. Many authors believe that the white tips of the paws in breeds such as the Sacred Burmese or the Snowshoe are determined by genes unrelated to the S locus. Their appearance is associated with a recessive allele.

Locus T (Tabby). It appears only against the background of allele A.
Allele a is epistatic to T.
T - determines the development of various patterns typical of wild representatives of the genus Felis and the immediate ancestor of the domestic cat Felis Libyca (Libyan cat). These colors are defined as tabby, brindle or mackerel.
Ta - Abyssinian. Named after the breed of cat for which it is most characteristic. The Abyssinian cat, while retaining the stripes on the face, completely lacks a motley pattern on the body. Sparse markings are visible on the front legs, thighs and tip of the tail. The hair has a clearly defined zonation (ticking).
tb - marble. Marbled cats have a characteristic pattern of wide dark stripes, spots and rings. The dark pattern is most clearly visible on the paws, tail and sides of the animal. The tb allele is recessive with respect to T and in a heterozygous state with it, Ttb gives striped coloring.
The Ta allele shows incomplete dominance in relation to the striped color allele T, as well as to the marbled color allele tb. Heterozygotes TTa and Tatb have residual pattern elements - ring stripes on the chest, faint stripes on the legs and “M” shaped markings on the forehead.

Locus W (White dominant)

White is not an independent color, but a complete absence of pigment.
Only one gene, designated by the letter W, blocks pigment cells. W is a pure white coat color that occurs as a result of the cessation of pigment synthesis at the very beginning of the chain of chemical reactions. The allele is incompletely expressive, and some kittens have a small dark spot on the head, which very rarely persists in adult cats. It also exhibits incomplete penetrance regarding eye color. Approximately 40% of white cats have blue eyes, and about half of them are deaf.
Blue eye color occurs due to a lack of pigment and complete absence tapetum in the iris, and deafness is due to a lack of pigment in the organ of Corti. The occurrence of these anomalies depends not so much on the dose of the gene, but on the presence of modifier genes and the activity of regulatory elements of the genome. Similar phenomena sometimes occur in white cats with residual pigmentation caused by the presence of the S allele. Sometimes such cats have partially or completely blue irises.
This can be explained by a violation of the formation of melanoblasts during embryogenesis. In very rare cases, the piebald gene causes some degree of deafness.
The effect of the W allele is similar to the effect of the S allele, but its effect on the reproduction of melanoblasts is more serious. Due to the similarity of the effects caused, it was even suggested that the W allele is one of the alleles of the S piebald locus.
w - the presence of color determined by the genetic formula of the animal. W>w.

Wb locus (Wideband).
Variegated cats, descended from heterozygous chinchilla cats, have a lighter shade of coat than regular tabbies. Their appearance suggests that these animals differ from ordinary tabbies by the presence of an additional allele. It is known that in some species of mammals an allele has been found that causes the appearance of a yellowish tint against the agouti background as a result of the expansion of the band of yellow pigment. This allele is called (Wide band). The coloration resulting from the expression of this allele may be called "golden tabby". The decrease in the amount of black pigment caused by this allele, in combination with the effect of allele I, is responsible for the formation of the chinchilla color. There is an assumption about a dominant mode of inheritance of this trait.

Where do tortoiseshell cats come from?

We already know that if both genes in a pair are responsible for the same characteristic, that is, they are completely identical, then the cat will be called homozygous for this trait. If the genes are not the same and carry different traits, then the cat will be called heterozygous for this trait. One of the hereditary characteristics is always stronger than the other. Black is always dominant, it is a stronger characteristic. The lilac color is recessive and is inferior to black. Two variants of the same characteristic located at the same locus, called an allele, can be both dominant, both recessive, or one dominant and the other recessive. The fact that one of the characteristics “recedes” to another does not mean the disappearance of the weaker characteristic. The recessive characteristic remains and is preserved in heredity, in the genotype. At the same time, the phenotype, that is, visible (externally manifested) characteristics, can demonstrate completely different colors. Therefore, in a homozygous animal the genotype coincides with the phenotype, but in a heterozygous animal it does not.
Red and black are located on the same locus on the X chromosome. In this sense, red is a “sex-linked” color. Cats, therefore, have only one gene for color - they can be either black or red. Cats have two X chromosomes and therefore two genes for color.
If a cat has two genes, for example, black, it is homozygous for black and has a black color. If a cat has one gene for black color and the other for red, then it has a tortoiseshell color. Tortoiseshell cats are a very rare exception. In addition to red and black, there are other varieties of tortoiseshell color. The most common is blue-cream, or, more correctly, blue tortoiseshell. Cats of this color have one gene for blue color, the other for cream, as derivatives of black and red, respectively.
Derivatives from the black color are dark brown (seul brown), blue, chocolate (chocolate brown), cinnamon (cinnamon). Lilac is a derivative of chocolate and blue. Fawn is a derivative of cinnamon and blue.
In the case where both alleles are identical in their characteristics, we will be presented with a homozygous cat. If one color allele in a cat is dominant and the other is recessive, then it will show the color of the dominant allele in its phenotype. A pair of heterozygous cats with a dominant coat color can produce offspring with a recessive coat color (but not vice versa!). In a double recessive (for example, lilac color), the phenotype and genotype are the same.
It is often difficult to understand the meaning of the term "sex-linked" in relation to the red color. The main practical significance of this rule is the ability to determine the colors and sex of future kittens from matings of two animals, one of which is red. There is an important rule of genetics that states that cats inherit the color of their mother. The term “weakened” or “loose” or “diluted” is often used to define colors derived from the two main ones. However, this is not always correct. Derivative colors are formed in two ways: by reducing the pigment granules per unit area and by grouping the same number of granules into bunches. The black color is formed by round pigment granules, which are spaced at an equal distance from each other. The blue color is formed by the same number of pigment granules, but grouped into bundles. Therefore, it is more correct to speak in in this case not about “dilution”, but about “grouping”.
The development of a chocolate (brown) color is an example of true dilution. Black pigment granules are elongated into ellipses. There are fewer granules per unit area.
Of the two sex chromosomes, only the X chromosome determines whether a cat will be black or red. Therefore, we can say that the Y chromosome of a cat does not carry information about color. Although the previous statements are correct, we must not forget that the Y chromosome actually contains a wealth of information about the possible color of a cat's fur. The locus on the X chromosome responsible for coat color only determines whether genes related to color will affect black or red.

International felinological systems have introduced a simple and convenient system of indexes for designating cat breeds and colors - EMS.

Main color

White (w) - white
Black (n) - black
Chocolate (b) - chocolate
Cinnamon (o) - cinnamon
Red (d) - red
Blue (a) - blue
Lilac (c) - lilac
Fawn (p) - fawn
Cream (e) - creamy

Black Tortie (f) - black tortoise
Chocolate Tortie (h) - chocolate turtle
Cinnamon Tortie (q) - cinnamon turtle
Blue Tortie (g) - blue
tortoise tortoise Lilac Tortie (j) - lilac tortoise
Fawn Tortie (r) - fawn tortoise

Availability of silver

Silver(s) - silvery

Eye color

61 blue - blue
62 - yellow, golden - yellow, orange, golden, etc.
63 oddeyed - odd eyes
64 green - green
65 burmese - eye color of Burmes cats
66 tonkinese - eye color of Tonkinese cats
67 himalayan or siam - the color of the eyes of the Himalayan and Siamese cats

Degree of white spotting

01 Van
02 Harlequin - harlequin
03 Bicolour - two-color, bicolor
04 Mitted/white point - with white markings for color points
09 Little white spots - white spotting 1-2 cm
11 Shaded - shaded (1/4 of the top part of the hair is darkened)
12 Tipped, shel - veiled (1/8 of the top part of the hair is darkened)

Tabby drawing

21 Tabby, agouti - striping, agouti factor
22 Blotched, marble - marble color
23 Mackerel, tiger - tiger color
24 Spotted - spotted color
25 Ticked - ticked or Abyssinian color

Tail length

51 - rumpy - rampy (no tail at all, in its place there is a hole)
52 - rumpy riser (tail with 1-2 vertebrae)
53 - stumpy (bob, short curled tail 7-13 cm)
54 - longy (regular tail)

Ear shape (fold, straight, etc.)

71 - straight straight (regular straight ears)
72 - curled (ears rolled back)
73 - fold fold (drooping ears)

Brown-classic-tabby - Black marble
Brown-spotted-tabby - Black spotted
Brown-mackerel-tabby - Black brindle
Brown-ticked-tabby - Black ticked

Blue-classic-tabby - Blue marble
Blue-mackerel-tabby - Blue brindle
Blue-spotted-tabby - Blue spotted
Blue-ticked-tabby - Blue ticked

Red-classic-tabby - Red marble
Red-mackerel-tabby - Red brindle
Red-spotted-tabby - Red spotted
Red-ticked-tabby - Red ticked

Cream-classic-tabby - Cream marbled.
Cream-mackerel-tabby - Cream brindle
Cream-spotted-tabby - Cream spotted
Cream-ticked-tabby - Cream ticked

Brown-silver-classic-tabby - Black silver marbled
Brown-silver-spotted-tabby - Black silver spotted
Brown-silver-mackerel-tabby - Black silver mackerel
Brown-silver-ticked-tabby

Blue-silver-classic-tabby - Blue silver marbled
Blue-silver-mackerel-tabby - Blue silver mackerel
Blue-silver-spotted-tabby - Blue silver spotted
Blue-silver-ticked-tabby - Blue silver ticked

Red-silver-classic-tabby - Red silver marbled
Red-silver-mackerel-tabby - Red silver mackerel
Red-silver-spotted-tabby - Red silver spotted
Red-silver-ticked-tabby - Red silver ticked

Cream-silver-classic-tabby - Cream silver marbled
Cream-silver-mackerel-tabby - Cream silver mackerel
Cream-silver-spotted-tabby - Cream silver spotted
Cream-silver-ticked-tabby - Cream silver ticked

With white markings - With white marks.

If the cat has white markings, then add with-white to the color:

Brown-classic-tabby-with-white - Black marbled with white
Red-classic-tabby-with-white - Red tabby with white
Black-torties-with-white - Black tortoise with white
Blue-torbie-with-white - Blue-cream marbled tabby tortoise with white
Smoke-black-torties-with-white - Smoky black torties with white

Black-torties - Black turtle
Blue-torties - Blue-cream tortoise
Smoke-black-torties - Smoky black tortoise
Smoke-blue-torties - Smoky blue cream turtle

Black-classic-torbie - Black marbled tabby tortoise
Blue-classic-torbie - Blue cream marbled tabby tortoise

Solid - Plain

Indexation of cat breeds

EXO - exotic
PER - Persian
MSO - Maine Coon
NFO - Norwegian Forest
RAG - ragdoll
SBI - Burmese
TUA - Turkish Angora
TUV - Turkish VAN
ABY - Abyssinian
SOM - Somali
SIB - Siberian
BRI - British Shorthair
BUR - Burmese
SNA - chartreuse
EUR - European Shorthair
JB - Japanese Bobtail
KOR - korat
MAN - manke
CRX - Cornish Rex
DRX - Devon Rex
GRX - German Rex
RUS - Russian blue
OCI - ocicate
MAU - Egyptian Mau
SIA - Siamese
BAL - Balinese
ORI - oriental
JAV - Javanese
non - unrecognized breeds

First about the reds. The gene for red color (“red” in cats is the color red, from the English Red) manifests itself differently in kittens depending on gender. As a result, various, very beautiful colors are possible, including tortoiseshell and blue cream. The red color never has a solid color - even the red solid color always comes in the form of a certain pattern - the “tabby” color. The pattern may be shaded to varying degrees, but will definitely appear in one way or another (in the form of stripes, spots or marble). In other solid (solid) colors, for example: blue, black, white, the pattern does not appear. Thus, it is impossible to understand what design, for example, a black cat carries. This can only be determined by her children.

Red cats in breeding programs.

A ginger male or female cat is a real jewel for a breeder! All breeders who use red-colored cats in breeding must understand the complex, sometimes confusing manifestation of the sex-dependent red gene. The color of the coat is provided by coloring pigments - eumelanin and faumelanin. Eumelanin gives the fur its black color, while faumelanin gives it its red color. The coat color gene responsible for the production of these substances is contained on the X chromosome. A cat has two such chromosomes - XX, a cat has one - XY. The same gene is responsible for black and red color, existing in two forms (alleles) - “O” - red and “o” - black. Therefore, a cat has three possible combinations - “Oo”, “oo” and “Oo”, while a cat has only “O” or “o”. It is clear that red-black colors are impossible in a cat, since both alleles are necessary for them.

By crossing a red cat with a blue cat, you will not get red kittens. Kittens can be black, blue, tortoiseshell or blue cream. It can also be noted that only cats will be blue and black, and tortoiseshell and blue-cream colors will appear only in cats. But when crossing a red cat with a tortoiseshell cat, you can see kittens of black, blue, tortoiseshell, red and cream colors of both sexes in the litter. To guarantee the birth of a red kitten, both parents must be red. Why does this happen?

To understand the reason, you need to remember that:

Cats have two genes responsible for coat color.
The red gene (which has no allele on the Y chromosome) is inherited from mother to son
Cats inherit one gene from each parent.

So, when crossing a red cat with a blue cat, male kittens will receive two genes for blue color, and female kittens will receive a red gene and a blue gene, giving colors mixed from these two colors - blue cream and tortoiseshell. On the contrary, in a red cat and a blue cat, male seals will receive two red genes, and female cats will receive one red gene and one blue gene - again blue-cream and tortoiseshell coat colors.

Cream is a diluted (lightened) red color. To produce cream and blue cream kittens, both parents must have the dilute gene. To ensure kittens of dilute colors, it is best to have both a male and female cat of “dilute” colors - blue and cream. Such parents cannot produce kittens with a dominant coat color - red or black.

Use of red studs in breeding programs for Chocolate and Lilac cats.

Completely different results will be obtained if you cross a red male with a chocolate or lilac cat. Chocolate and lilac are rare colors. (Well, of course, this does not apply to Maine Coons, since in our breed lilac and chocolate colors are not allowed, at least for now) In order to get a chocolate tortoiseshell or lilac-cream coat color in kittens, you need to have both parents carrying the gene for a chocolate or lilac color, and best of all, those who have this color themselves. It’s good if the cat has a cream color (diluted red).

Calculation of the color of kittens with the participation of red parents

Cat	Cat	Kittens - cats	Kittens - cats
red	black chocolate	black chocolate	tortoiseshell blue cream chocolate turtle lilac-cream
red	red cream	red cream	red cream
red	tortoiseshell blue cream chocolate turtle lilac-cream	black chocolate	red cream tortoiseshell blue cream chocolate turtle lilac-cream
black chocolate	red	red	tortoiseshell blue cream chocolate turtle lilac-cream

Now a little about everyone.

The European Feline Federation FIFe has introduced a simple and convenient system of indexes for designating cat breeds and colors - EMS.

Below are some of the indices that are used when entering the genotype of a cat and when issuing calculation results.

Main color

(w) White - white

(n) Black, Seal – black

(b) Chocolate – chocolate (dark brown)

(o) Cinnamon – cinnamon (light brown)

(d) Red - red

(a) Blue - light blue

(p) Fawn – fawn (beige)

(e) Cream - creamy

(f) Black Tortie (black with red)

(h) Chocolate Tortie – chocolate turtle (dark brown with red)

(q) Cinnamon Tortie (light brown with red)

(g) Blue Tortie – blue tortoise (blue-cream color)

(j) Lilac Tortie – lilac tortoise (lilac-cream color)

(r) Fawn Tortie – fawn tortoise (beige with cream)

Availability of silver

(s) Silver - silvery

Degree of white spotting

(01) Van

(02) Harlequin - harlequin

(03) Bicolour - bicolor

(09) Little White Spots

Tabby drawing

(22) Classic tabby – marbled

(23) Mackerel tabby – brindle

(24) Spotted tabby - spotted

(25) Ticked tabby - ticked

Point color type

(32) Mink – Tonkinese

(33) Point – Siamese (color-point)

Genetics of red and black.

The entire rich palette of cat colors depends in general on two coloring substances - eumelanin and faumelanin. The first is responsible for the black color (and its derivatives - chocolate, blue, lilac, fawn, cinnamon, the second - for red (cream). The genes that are responsible for the appearance of red (O - orange) or black (o - not orange) are located on the X chromosome, that is, the inheritance of color is linked to sex.Cats have two X chromosomes and, accordingly, three color options:

- OO - red

- oo - black

- Oo - tortoiseshell.

Cats have one X chromosome and, depending on which gene it carries O or O, it will be red or black. Tortoiseshell coloring in cats appears only in the case of genetic mutations.

Thus, the inheritance of traits whose genes are located on the X or Y chromosome is called sex-linked. Genes localized on the X chromosome and not having alleles on the Y chromosome are inherited from mother to son, in particular, a red cat will not be born from a black cat, and vice versa, a red cat will not give birth to a black series cat.

Agouti and non-agouti

The colors of cats are very diverse. Some cats are uniformly colored - these are the so-called solid colors or solids. Other cats have a pronounced pattern - in the form of stripes, circles. This pattern is called tabby. Tabby “opens” on the coat thanks to the dominant gene A - agouti. This gene colors each cat's hair with evenly alternating dark and light transverse stripes. In dark stripes, a larger amount of eumelanin pigment is concentrated, in light ones - less, and the pigment granules elongate, acquiring an ellipsoidal shape and are located sparsely along the length of the hair. But if a homozygous allele (aa) – non-agouti – appears in the genotype of an animal with a black color, the tabby pattern does not appear and the color turns out to be solid. This influence of some genes on other genes that are not allelic with them is called epistasis. That is, the allele (aa) has an epistatic effect on the tabby genes, it “covers” them, masks them, and prevents them from appearing. However, allele (aa) does not affect the O (orange) gene. Therefore, cats of red (cream) color always have an open tabby pattern.

Thus, all cats are tabbies, but not all are agoutis. Confirmation that all cats have a tabby in their genotype is the residual “ghost” baby tabby in many kittens. This residual tabby in cats of solid colors goes away, the cat sheds, the coat changes and becomes evenly colored.

Red series colors

The red series consists of only two colors: red and cream (a dilution of red). The red color is gender-linked. This means that the locus of this gene is located on the X chromosome, and inheritance of the red color is carried out through this particular sex chromosome. The red color gene provokes the production of the pigment pheomelanin, as a result of which the cat's fur acquires different shades of red. The intensity of the red color is influenced by the lightening gene, designated by the letter D (Dilutor). This gene in a dominant state allows the pigment to lie tightly along the entire length of the hair. A homozygous combination of recessive dd genes provokes a sparse arrangement of pigment granules in the hair, diluting the color. In this way, a cream color is formed, as well as lightened tortoiseshell variations (blue cream and lilac cream).

As noted above, red series cats always have an open tabby pattern. The solid red color appears as a result of breeding work, by selecting sires that have the most shaded, blurry tabby pattern.

Silver and gold

In the silver group of cats, only the end of each hair is colored and the root part of the hair is practically bleached (silvered). On the genetic background of non-agouti, the aa guard hairs under the influence of the inhibitor gene I do not stain almost half the length, and the undercoat remains completely white. This color is called smoky. But smoky colors with poorly bleached, grayish undercoat are often found. In smokes, the white part of the hair is approximately 1/8.

In silver tabbies, colors that develop under the influence of an inhibitor gene based on the A- genotype, the hairs in the pattern are colored almost to the base, while in the background guard coat only the tips remain colored.

The extreme degree of activity of the inhibitor gene is shaded and shaded (chinchilla) colors. In the first, the tip is painted approximately 1/3-1/2 of the length, and in the second, only 1/8, without stripes. This distribution of color throughout the hair is called tipping. “Cameo” is added to the names of the colors of shaded and shaded cats of the red series.

Thus, the genotype of Chinchilla, Shaded silver, Pewter (Shaded Silver with copper eyes) and Silver Tabby is A-B-D-I-. The difference in colors is caused by sets of polygenes. Chinchillas are brown tabbies, modified under the influence of an inhibitor gene and over many generations selected for the shortest tipping and the most shaded tabby pattern.

Smoky cats of the black series have the genotype: aaB-D-I-.

Red silvers have the genotype D-I-O(O). Red smokes can be genetically either agouti or non-agouti.

The main feature of the golden color is that from 1/2 (golden tabbies) to 2/3 (golden shaded) and 7/8 (chinchillas) parts of each guard and integumentary hair are colored in a light or bright apricot, warm tone. The shades of this tone in different parts of the cat’s body may vary, but do not turn into dull grayish tones.

Often in golden tabbies and golden shadeds there are residual ticking stripes on the darkly colored part of the guard hairs, which blurs the tabby pattern or gives a sloppy appearance to the shaded color. Also often found are intermediate colors between golden and regular black tabbies: the guard hairs are colored gold and the undercoat is gray.

Among the patterned golden cats, there is another variation of the golden color - the undercoat is golden, the background of the coat is well lightened, and the outer hairs in the pattern are darkened almost to the roots. There are no ticking stripes and the “gold” is an intense, almost copper color.

The genotype of golden colors: A-B-D-ii, that is, the same as that of Black Tabbies, and the phenotypic difference appeared as a result of selective selection and the accumulation of certain polygenes in the genotype.

There is a theory of bigenesis of gold and silver colors. That is, the genes responsible for the silver color (inhibitors of melanin, and its yellow modification - pheomelanin) act independently of the genes of the golden color - inhibitors of eumelanin, black pigment (the fact that the golden color gene is also a pigment inhibitor is indicated by the correlation of color with green - unpainted - eye color). Each of these genes must be represented by at least two alleles that are active in an agouti or nonaguchi background.

ELEMENTARY RULES OF GENETICS OF CAT COLOR:

Two long-haired parents cannot produce a short-haired kitten.

Only the parents' colors determine the color of the kitten. The colors of other cats present in the pedigree do not have a direct effect on the color of the kitten.

A cat kitten always gets its color from its mother.

A cat kitten always receives a color that is a combination of the colors of the father and mother.

To produce a genetically red or genetically cream female kitten in a litter, the father must be genetically red or genetically cream, and the mother must also have a red or cream color in her genotype.

Dominant characteristics (dominant colors: white, silver, tabby, bicolor, etc.) cannot skip a generation. They cannot pass, for example, from grandfather to grandson, without manifesting themselves in the father.

A dominant colored kitten (black, red, tortoiseshell, etc.) must have a dominant colored parent.

Two parents of a recessive color (cream, blue, etc.) cannot produce a kitten of a dominant color (black, red, tortoiseshell, etc.)

A white kitten must have a white parent.

A kitten with a white undercoat (veiled, shaded, smoky) must have a parent with a white undercoat.

A veiled/shaded kitten must have at least one parent who is either veiled/shaded or a tabby.

A veiled/shaded parent can produce a smoky kitten, but a smoky parent cannot produce a veiled/shaded kitten.

A tabby kitten must have at least one parent who is either veiled/shaded or tabby.

All red cats have some degree of tabby. The ability to produce tabby offspring depends on whether the red cat (or tom) is a true tabby, i.e. does she have a tabby or veiled/shaded parent, or is she just a red cat with a pronounced tabby pattern. A red tabby, unless it is a true tabby, cannot produce a tabby offspring of any other color unless it is bred to a true tabby (or a veiled/shaded one).

A brindle tabby kitten must have a brindle tabby parent.

A spotted tabby kitten must have a spotted tabby parent.

Multi-colored individuals (tortoiseshell, blue-cream, calico, tortoiseshell and white, tortoise-point, etc.) are almost always cats, but sometimes sterile cats are born.

A bicolor kitten must have a bicolor parent.

Two color-point parents cannot produce a non-color-point kitten

It is possible to get a Himalayan kitten only if both parents are carriers of the Himalayan color (even if they themselves are a solid color).

If one parent is of the Himalayan color, and the other is not and is not even a carrier of the Himalayan color, then not a single kitten of the Himalayan color can be in the offspring.

Dominant and recessive colors

Black dominates blue

Black dominates chocolate

Chocolate dominates over lilac

Chocolate dominates light brown

White dominates all other colors

Tortoiseshell dominates blue cream

Tortoiseshell and white (calico) is dominant over weakened tortoiseshell and white (blue cream and white)

The solid color is dominant over the Siamese

Solid color dominates Burmese

Siamese dominates albino with blue eyes

Variegated (almost white) dominates over solid colors

Ticking Tabby Dominates Black

Ticking tabby (agouti) is dominant over all tabby varieties

The brindle tabby is dominant over the marbled or classic tabby.

White spotting dominates the solid color

An albino with blue eyes dominates an albino with pink eyes.

The white undercoat dominates the solid color

Formation of color

Today there is an amazing variety of cat colors. Some of them were inherent to them initially, others were obtained, developed and consolidated by restless breeders. But if you look at it, there are very few primary colors on which this entire palette is based. These are: black, blue, brown, lilac, chocolate, beige, red, cream, yellow. Of course, there is also white, but due to the fact that it is not a color, but quite the opposite - its absence, it is called a color symbolically.

The color of the coat depends on the type of a very complex substance in its composition - the melanin pigment, which creates a particular color. Melanin is produced in specialized cells called melanocytes. The source for its formation is the amino acid tyrosine (entered into the body with food). Through biochemical processes, tyrosine is converted into pigment. With the help of a protein catalyst called tyrosinase.

Information about the amino acids that make up tyrosinase is contained in a gene known as Colog - color. There are only four pigments in the cat world. The two main, basic pigments are eumelanin and pheomelanin. They exist in the form of pigment grains (mylanosomes) of various shapes.

The perception of color depends on the refraction of light passing through or reflecting from them. The granules form a somewhat elongated ellipsoidal or spherical shape and can vary widely in size.

Eumelanin is presented in three modifications: black pigment - eumelanin itself and two of its derivatives - brown and cinnamon pigments (mutant form of eumelanin).

Eumelanin granules give the hair high mechanical strength, which affects the elasticity of black wool. This pigment is very stable: insoluble in organic solutions and resistant to chemical treatment.

Pheomelanin granules are characterized by a classic yellow or orange color. Unlike eumelanins, they have a much smaller, spherical shape.

The scale-like structure of the cells of such hair is much less durable than the structure of cells containing eumelanin. And also, unlike eumelanin, which is present not only in hair, but also in skin, pheomelanin is present only in hair.

The process of color formation is called pigmentogenesis. It begins in the embryonic stage of development of the embryo, in the area of the neural tube, from where the anlage of future pigment cells is released, which, in order to gain the ability to produce pigment, must undergo a number of changes:

1. Take on a spindle-shaped shape appropriate for migration and go to the hair follicles.

2. Migrate to the centers of pigmentation, which are located in cats on the crown, back, withers and at the root of the tail. (These centers are clearly indicated by the colored areas of the coat in Van cats.)

3. Penetrate the hair follicle (follicle) before its final formation. And only after that they become full-fledged pigment-producing cells - melanocytes.

Next, a complex biochemical process continues, the end result of which is the color of the cat. This process depends on the degree of influence and relationships of the simultaneous action of dozens of genes. In order to write down the minimum genetic formula of color, it is necessary to use almost the entire Latin alphabet, even if it does not contain the factors that determine the length, thickness and density of the coat, and there are many other characteristics on which the color of the coat depends.

After all, even two, at first glance, absolutely identically colored cats can have different genetic formulas and vice versa. The rules of inheritance of cat colors are currently considered the most studied and controlled. Knowing them is necessary for breeders to correctly and competently plan breeding programs for their animals in order to obtain colors in the offspring that meet recognized standards.

A complex of genes is responsible for a cat's color. These genes can be divided into three main groups: the first includes genes that control coat color, the second those that affect the intensity of color expression, and the third determines the location of the pattern or its absence. Although each of these groups works in its own direction, there is a close relationship between them.

Loci responsible for color.

Locus A “agouti” - (agouti). The locus is responsible for the distribution of pigments along the length of the cat's hair and body. The pigments eumelanin and pheomelanin form alternating stripes on each hair, the so-called “ticking”. Cats with agouti colors are characterized by the presence of a light mark in the shape of a human thumb print on the back of the ear, as well as a pink or brick-red nose, bordered by a narrow dark stripe.

A - promotes the formation of wild color.

a - “not agouti.” Under the influence of this allele, pigments are evenly distributed along the length of the hair. The hair of short-haired cats is colored evenly from base to end, while in long-haired cats there is a gradual decrease in color intensity towards the base of the hair. In small kittens, in bright light, you can detect a slight trace of a mottled pattern against a dark background, which disappears in an adult animal.

Black, chocolate, brown and blue cats have solid color, determined by the aa genotype.

Locus B (Blask). As in other animal species, it is responsible for the synthesis of eumelanin.

B - black color. b - brown (chocolate). To denote the dark brown coat color observed in cats homozygous for the b allele, breeders introduced the special term “chocolate color.”

b1 - light brown, the so-called cinnamon color (cinnamon).

Black color is completely dominant over brown, and in brown there is incomplete dominance of the b allele over b1. In cats, brown color is much less common than black, and it is practically absent in natural populations.

Locus C (Color) is a series of albino alleles.

C - ensures normal synthesis of pigments.

cch - silver color. However, R. Robinson does not recognize the existence of this allele in cats.

There is a group of alleles at this locus that causes uneven coloring on a cat's body. Such animals have a dark muzzle, ears, limbs and tail, and a much lighter body. These colors result from the presence of a temperature-sensitive form of tyrosinase, which is involved in the synthesis of melanin. At normal body temperature, the activity of this form of tyrosinase is sharply reduced, which leads to lightening of the color. The reduced temperature of the limbs, tail, muzzle and ears promotes the activation of the enzyme and triggers normal melanin synthesis, which ensures the development of the typical “Siamese” color. Experiments have shown that raising Siamese kittens in the cold leads to the formation of a solid dark color, and at elevated temperatures - a light color. This group includes two alleles cb and cs.

cb - Burmese albino. Homozygous cbcb animals have a dark sepia brown coloration, gradually becoming lighter towards the belly. The head, paws and tail of such animals are much darker.

ss - Siamese albino. Typical Siamese color. Homozygotes csсs have a body color the color of baked milk or lighter, as well as a dark muzzle, paws and tail. Siamese cats have a blue iris.

ca - blue-eyed albino. Cats of the Sasa genotype have white fur, light blue irises and translucent pupils.

c - albino with pink eyes. Its homozygotes also have a white coat color, but the iris is devoid of pigment.

Allele C is completely dominant over all other alleles of the locus. Intermediate dominance is observed between the cs and cb alleles. Csсb heterozygotes are called Tonkinese and have a color intermediate between Siamese and Burmese and turquoise eyes.

The ca and c alleles are recessive to all higher-level alleles, but how they interact with each other is unknown, since they are extremely rare.

Locus D (Dense pigmentation) - intensity of pigmentation.

D - full intensity pigmentation.

d - the main color is weakened.

Due to the gluing of pigment granules, the uniformity of their entry into the growing hair is disrupted, which leads to an accumulation of granule mass in some areas and a deficiency in others. Individuals homozygous for the d allele have a lightened color: blue, lilac, golden. Wild tabby cats have a lighter color while maintaining a warm yellowish tone.

Locus I (Melanin inhibitor). According to R. Robinson, one mutant allele is currently known at this locus.

I - this allele promotes the accumulation of pigment granules at the end of the hair. At the base of the hair, the amount of accumulated pigment is minimal, which looks like complete bleaching of the hair roots. This distribution of pigment throughout the hair is called tipping.

The effect of this allele can be observed mainly on long hair. The manifestation of the effect of allele I depends on the alleles of other loci. Thus, in cats homozygous for a, the effect of allele I is manifested in the appearance of a light or white undercoat. These colors are called smoky. In tabby cats, the light areas become almost white, and the dark hair in the area of stripes and spots synthesizes pigment almost completely. This color is called silver.

In ginger cats, there is a general weakening of pigmentation and discoloration of the undercoat - a cameo phenotype occurs. However, it has now been proven that the expressivity of allele I fluctuates very highly, and therefore it is not entirely legitimate to call it dominant. Maximum expression leads to the accumulation of pigment only at the end of the hair by 1/3 of its length in the so-called shaded ones, and by 1/8 in the shaded ones, or, in other words, chinchillas. The color of the ends of the hair depends on the alleles of the B, D and O loci.

i - normal distribution of pigments in the hair.

Locus O (Orange). The trait determined by this locus belongs to the group of sex-linked ones.

O - located on the X chromosome (sex chromosome), leads to the cessation of eumelanin synthesis.

Homozygous cats and homozygous cats have red color.

The effect of the allele is manifested only in the presence of allele A, allele a is epistatic in relation to O. Therefore, the vast majority of ginger cats have a characteristic striped pattern caused by the T locus (tabby).

o - color determined by the basic genetic formula of the animal. It appears as non-red spots on the body of a tortoiseshell cat, which can be black, blue, striped, etc.

Locus P (Pink eyed) - “pink eyes”.

P - color determined by the basic genetic formula of the animal.

p - cats homozygous for this allele have a characteristic lightened reddish-brown fur color and reddish-pink eyes. The mutation is extremely rare, and the nature of inheritance of this trait has not yet been sufficiently studied.

Locus S (Piebald spotting) - white spotting.

Represented by a series of multiple alleles.

Sw - Van color - white with two small spots on the head and a colored tail.

Sp - spotted harlequin color.

s - solid color without white spots.

There is no doubt that, in addition to the main alleles of the locus, a large number of modifier genes are involved in the formation of spotted colors, just as it happens in animals of other species. Many authors believe that the white tips of the paws in breeds such as the Sacred Burmese or the Snowshoe are determined by genes unrelated to the S locus. Their appearance is associated with a recessive allele

Locus T (Tabby). It appears only against the background of allele A.

Allele a is epistatic to T.

T - determines the development of various patterns typical of wild representatives of the genus Felis and the immediate ancestor of the domestic cat Felis Libyca (Libyan cat). These colors are defined as tabby, brindle or mackerel.

Ta - Abyssinian. Named after the breed of cat for which it is most characteristic. The Abyssinian cat, while retaining the stripes on the face, completely lacks a motley pattern on the body. Sparse markings are visible on the front legs, thighs and tip of the tail. The hair has a clearly defined zonation (ticking).

tb - marble. Marbled cats have a characteristic pattern of wide dark stripes, spots and rings. The dark pattern is most clearly visible on the paws, tail and sides of the animal. The tb allele is recessive with respect to T and in a heterozygous state with it, Ttb gives striped coloring.

The Ta allele shows incomplete dominance in relation to the striped color allele T, as well as to the marbled color allele tb. Heterozygotes TTa and Tatb have residual pattern elements - ring stripes on the chest, faint stripes on the legs and “M” shaped markings on the forehead.

Locus W (White dominant). Dominant white color.

W - pure white coat color, resulting from the cessation of pigment synthesis at the very beginning of the chain of chemical reactions. The allele is incompletely expressive, and some kittens have a small dark spot on the head, which very rarely persists in adult cats. It also exhibits incomplete penetrance regarding eye color. Approximately 40% of white cats have blue eyes, and about half of them are deaf.

Blue eye color occurs due to a lack of pigment and the complete absence of tapetum in the iris, and deafness is due to a lack of pigment in the organ of Corti. The occurrence of these anomalies depends not so much on the dose of the gene, but on the presence of modifier genes and the activity of regulatory elements of the genome. Similar phenomena sometimes occur in white cats with residual pigmentation caused by the presence of the S allele. Sometimes such cats have partially or completely blue irises.

This can be explained by a violation of the formation of melanoblasts during embryogenesis. In very rare cases, the piebald gene causes some degree of deafness.

The effect of the W allele is similar to the effect of the S allele, but its effect on the reproduction of melanoblasts is more serious. Due to the similarity of the effects caused, it was even suggested that the W allele is one of the alleles of the S piebald locus.

w - the presence of color determined by the genetic formula of the animal. W>w.

Wb locus (Wideband).

Variegated cats, descended from heterozygous chinchilla cats, have a lighter shade of coat than regular tabbies. Their appearance suggests that these animals differ from ordinary tabbies by the presence of an additional allele. It is known that in some species of mammals an allele has been found that causes the appearance of a yellowish tint against the agouti background as a result of the expansion of the band of yellow pigment. This allele is called (Wide band). The coloration resulting from the expression of this allele may be called "golden tabby". The decrease in the amount of black pigment caused by this allele, in combination with the effect of allele I, is responsible for the formation of the chinchilla color. There is an assumption about a dominant mode of inheritance of this trait.

Where do tortoiseshell cats come from?

Red and black are located on the same locus on the X chromosome. In this sense, red is a “sex-linked” color. Cats, therefore, have only one gene for color - they can be either black or red. Cats have two X chromosomes and therefore two genes for color.

If a cat has two genes, for example, black, it is homozygous for black and has a black color. If a cat has one gene for black color and the other for red, then it has a tortoiseshell color. Tortoiseshell cats are a very rare exception. In addition to red and black, there are other varieties of tortoiseshell color. The most common is blue-cream, or, more correctly, blue tortoiseshell. Cats of this color have one gene for blue color, the other for cream, as derivatives of black and red, respectively.

Derivatives from the black color are dark brown (seul brown), blue, chocolate (chocolate brown), cinnamon (cinnamon). Lilac is a derivative of chocolate and blue. Fawn is a derivative of cinnamon and blue.

In the case where both alleles are identical in their characteristics, we will be presented with a homozygous cat. If one color allele in a cat is dominant and the other is recessive, then it will show the color of the dominant allele in its phenotype. A pair of heterozygous cats with a dominant coat color can produce offspring with a recessive coat color (but not vice versa!). In a double recessive (for example, lilac color), the phenotype and genotype are the same.

It is often difficult to understand the meaning of the term "sex-linked" in relation to the red color. The main practical significance of this rule is the ability to determine the colors and sex of future kittens from matings of two animals, one of which is red. There is an important rule of genetics that states that cats inherit the color of their mother. The term “weakened” or “loose” or “diluted” is often used to define colors derived from the two main ones. However, this is not always correct. Derivative colors are formed in two ways: by reducing the pigment granules per unit area and by grouping the same number of granules into bunches.

The black color is formed by round pigment granules, which are spaced at an equal distance from each other. The blue color is formed by the same number of pigment granules, but grouped into bundles. Therefore, it is more correct to speak in this case not about “dilution”, but about “grouping”.

The development of a chocolate (brown) color is an example of true dilution. Black pigment granules are elongated into ellipses. There are fewer granules per unit area.

Of the two sex chromosomes, only the X chromosome determines whether a cat will be black or red. Therefore, we can say that the Y chromosome of a cat does not carry information about color. Although the previous statements are correct, we must not forget that the Y chromosome actually contains a wealth of information about the possible color of a cat's fur. The locus on the X chromosome responsible for coat color only determines whether genes related to color will affect black or red.

In contact with

(w)White - white
(n) Black, Seal - black
(b) Chocolate – chocolate (dark brown)
(o) Cinnamon – cinnamon (light brown)
(d)Red - red
(a) Blue – blue
(c) Lilac – lilac
(p) Fawn – faun (beige)
(e)Cream – cream

(f) Black Tortie – black turtle (black with red)
(h) Chocolate Tortie – chocolate turtle (dark brown with red)
(q) Cinnamon Tortie – cinnamon turtle (light brown with red)
(g) Blue Tortie – blue turtle (blue-cream color)
(j) Lilac Tortie – lilac tortoise (lilac-cream color)
(r) Fawn Tortie – fawn tortoise (beige with cream)

Availability of silver:
(s)Silver – silver

Degree of white spotting:
(01) Van – van
(02) Harlequin – harlequin
(03) Bicolour – bicolor
(09) Little White Spots – residual spotting

Tabby pattern:
(22) Classic tabby – marble
(23) Mackerel tabby – brindle
(24) Spotted tabby – spotted
(25) Ticked tabby – ticked

Point color type:
(31) Sepia – Burmese
(32) Mink – Tonkinese
(33) Point – Siamese (color-point)

All the specific characteristics of purebred cats that a felinologist deals with: color, head shape, ear placement and the like are, of course, determined polygenically. However, in some cases, knowing the path of development of a trait, it is difficult to consider its inheritance as a system of independent genes. A similar complex trait is cat color.

The number of currently known cat colors has exceeded two hundred. Their classification and descriptions can be found in almost any cat breed standards. “Murks” on the streets of our cities, although they do not represent the wealth of cat colors in all their splendor, still create an idea of the variety of color combinations of the cat world. Everyone has probably met cats of a “wild” color, whose grayish-brown fur is streaked with black tiger stripes or marble stains, and pure black cats, as well as red and blue ones, which are called “smoky” in everyday life.

By the way, the last two colors are known by felinologists as “red” and “blue”. Surely everyone is familiar with “Siamese” cats color- with a darkened muzzle-mask, ears and tail and a light body. Any of these colors can also be combined with white spots - of various sizes and shapes. But is the palette of cat colors really so rich - that is, how many colors make up it? Of course, not two hundred or even fifty. Black, blue, chocolate, brown, cinnamon, lilac, beige, red (depending on the intensity from light red to brick red), cream, yellow - that’s probably all. White color in the proper sense is not a color at all - it is “uncolored,” the absence of a pigment that creates a particular color.

To understand how so many colors of a cat’s coat are formed and how the color of each specific cat is genetically determined, we will have to consider the entire process of color formation - pigmentogenesis. This process begins at the embryonic stage. At very early stages of development, the germ of future pigment cells is secreted in the area of the neural tube. They themselves cannot yet produce pigment; to do this they need to undergo a number of changes. First of all, they must take on a spindle-shaped shape suitable for migration. These cells migrate first to the center of pigmentation, and from there to the hair follicles. This process; is under the control of the White gene, and if this gene is represented in a cat by two normal recessive alleles w, the progenitor cells unmistakably acquire the form necessary for migration. But if at least one of the alleles is dominant mutant W, the cells lose the ability to organize, remain in the same place and will not produce pigment in the future, and the cat is a carrier of the dominant allele White - will remain unpainted, that is, white.

There are, however, exceptions when some of these cells are still capable of short-term pigment synthesis: many are familiar with the children's “colored cap” on the head of white kittens.

By the way, the dominant white gene color and (this is its full name) can disrupt the formation of not only future pigment cells, but also nearby cells - the iris of the eye and the organ of Corti. As a result, blue-eyed (one or both eyes) and even deaf cats are formed. This phenomenon depends not so much on the dose of the gene, that is, the cat carries two or only one W allele (R. Robinson’s studies showed that the percentage of blue-eyed cats among Ww heterozygotes is slightly lower than among WW homozygotes), but on the presence of modifier genes and activity of regulatory elements of the genome.

Locus White Dominant – dominant white; Piebald White locus

Spotting - white piebald (spotting)

White Dominan t and non white

w – normal gene

Mechanism of action of the White Dominant gene

Blockade of the movement of primary pigment cells in the earliest stages of neural tube formation into the follicles of growing hair, into the iris of the eye and into the auditory nerve

Phenotype

White wool

White color

The eyes are blue, yellow, odd-eyed, sometimes light green (salad). One or more small colored spots on the crown and base of the tail disappear with age (baby cap) (variable expressiveness).

Dominant epistasis

Suppresses the expression of all other genes color

Pleiotropic effects

Deafness
Decreased vitality and fertility
Choleric or melancholic character - a decrease in the strength of nervous processes, both excitation and inhibition.

Thus, the W allele for the actual white color shows 100% penetrance and almost complete expressivity (in rare cases, young white cats have a residual color spot on the crown). Much lower penetrance of the same gene for blue-eyed (about 40%) and deafness (about 20%) in natural cat populations. Of course, due to selection during artificial breeding, these indicators change.
So, at the first stage of pigmentogenesis, it is determined whether the cat will be colored or remain white. After the pigment cells have taken the desired shape, they begin to migrate, initially to the so-called pigmentation centers, from where they disperse along the entire surface of the body.

The location of the centers of pigmentation is clearly visible from the position of the colored spots on the body of cats of the so-called Van color and harlequin color: these are primarily spots on the crown and at the root of the tail, as well as on the back and withers. They indicate the position of the centers of pigmentation.
In order for propigment cells to turn into full-fledged, pigment-producing cells (such cells are called melanocytes), they must have time to penetrate the hair follicle (follicle) before its final formation.

The combination of the speed of these processes - the movement of progenitor cells and the formation of hair follicles - determines how colored the cat will be and whether it will retain white patches. An equal role in this process is given to the white piebald (or white spotting) gene - Spot, or rather, Piebald Spotting (symbol S). In cats homozygous for its recessive allele - ss - the color develops completely, but the action of the semi-dominant allele S causes varying degrees of white spotting. The spectrum of this white piebald is extremely wide: from an almost white color with a colored tail and spots on the crown ( Van color) to almost fully developed color with a small white “medallion” on the chest.

Previously, it was assumed that the entire variety of white and piebald colors was determined only by activity allele S, inhibiting the movement of propigment cells. Activity depends on the genetic background and gene dose - that is, homozygous cats will have a Van or harlequin color, and Ss heterozygotes will have colors from bicolor (about half of the cat's body is painted) to full color with residual spots on the chest, groin, and paws. Currently, some felinologists have come to the conclusion that the white piebald gene has not two allelic states, but more, that is, we can talk about the allelic series of the S gene (but, of course, each cat usually contains in its genotype only two of any allele a series). It is believed that Van color determined by the most dominant allele of the Sw series. Harlequin color, in which colored spots are scattered in separate areas over the head, withers, back and rump of the cat with the second most dominant allele, Sp.

Piebald White Spotting
Piebald, white spots in color

s – normal gene

Phenotype

Fully painted
self or solid

With white spots (piebald)

Piebald White Spotting

Mechanism actions gene
Piebald White Spotting

Delays the movement of pigment cells to their final destinations from critical points
The effect of the gene is limited in time by the embryonic development of the kitten
At the same dose, the gene manifests itself differently - varying penetrance

Allelic series gene
Piebald White Spotted

S v >S h >S i >S g >S o >S>

van - harlequin - inok - gloves - ojos azules – little white spotting - self

Van color

Colored spots on the head, ears, colored tail. A single colored spot on the body. The total size of colored spots is no more than 10%. Ideal color required for Van breed cats: a colored cap with a white blaze on the crown of the head, white ears, a fully colored tail. A single spot on the body, preferably in the area of the shoulder blade.

Harlequin

Chaotic arrangement of colored spots on a predominant white field. Colored spots on the head, at the base of the tail and at least one on the back or side. The total size of the colored part of the body is 30% or less

Allele S determines the bicolor color ratio - approximately 1:1, with the upper part of the body painted and the lower part unpainted. Finally, it is likely that the residual white spots are determined by its own allele si, which is recessive even in relation to allele full coloring s. However, the relationships within pairs of these alleles are still not strictly defined, and the effect of the genetic background and modifier genes has a very significant effect on the variations of white spotting.

The second stage of pigmentogenesis thus determines whether the animal is fully or partially colored.

By the way, “white paws” in breeds such as the Sacred Burmese or Snowshoe are in no way associated with the genes for the white piebald locus. Their appearance is determined by a completely independent recessive mutant gene gl (gloves), the action of a dominant allele which does not appear at all externally.

***Bicolor or* color *with white***

The ideal distribution of colored and unpainted parts in a cat's color is 50:50. White lower half of the body, including the limbs. The white zone continues from the neck to the muzzle in the form of an isosceles triangle with the apex between the eyes. Eyes on the painted part of the head. Full white collar. Flaws color: white spots on the “cloak” - “torn cloak”. Colored spots on white areas: on the limbs, chest, stomach - “spotted” bicolor. Asymmetrical or absent white triangle on the muzzle. Reduction in the size of plasterons less than 30% of the body surface

Sg – gloves,
terminal white spot

Occupies no more than 1/3 of the body
Spreads to lower body
Occupies the throat, lower neck, stomach, tips of the paws

Forms “socks”, “gloves”, “boots”

***Burmese* *color***

Caused by a separate gene - gg / SgSg

Cultivated only in the colorpoint division colors in Burmese cats and American Snowshoes. The shape of the white markings on the limbs is stable and is transmitted only through homozygous selection of parental pairs. Not fixed in other colors. Presumably inherited by an independent recessive gene.

s – self or solid, fully painted
When assessing color, pay special attention to minimal white spots, sometimes consisting of one hair, in the groin, on the throat, on the pads of the paws

White tip spotting combined with blue eyes

Gene S o

First described in California. The gene is named Ojos Azules
An analogue, separated in time and space – Altai blue-eyed
Genetic identity not proven
There must be a white mark on the tip of the tail, the tip of the muzzle or the crumb of the finger
Breeding with bicolors is not advisable

Epistasis and pleiotropic action of the white spotting gene

With a large area of the white spot, it masks the effect of other color genes
Sometimes it causes the color of the iris to lighten to light green. With complete unilateral blockade of pigment in the iris - unilateral or bilateral blue eyes
Sometimes - hearing loss
Modifies the tortoiseshell coloration in females - increases the plasterons of colored spots

So, the pigment cells reached the hair follicles and transformed into melanocytes, which may have already started producing pigment. This complex biochemical process is controlled by one's own genes. To convert the amino acid tyrosine (it enters the body with food) into melanin (more precisely, into the propigment (promelanin), from which melanin is formed in the next stage), the enzyme tyrosinase is required. The formation of this regulatory enzyme protein is determined by the gene of the so-called Color (C) locus.

Locus this, by the way, has been well studied and is present in all mammals, and is represented by a whole series alleles. The dominant allele C ensures the synthesis of normal tyrosinase, and then the individual is fully colored. The recessive mutant allele cs produces tyrosinase, which is somewhat unusual - its ability to perform its regulatory function is limited by temperature, in other words, this enzyme is activated only in the cold. Therefore, homozygous allele cs well-known Siamese cats have intense coloring only in the most cooled, protruding areas of the body - the muzzle (“mask”), ears, tail and paws.

A similar picture develops when a cat is homozygous for another mutant allele of the same series - cb. Color, called Burmese (otherwise Burmese), although darker and less contrasting than the color of the Siamese, it retains the same pattern of intense coloring of the protruding areas of the body (why are these colors also called acromelanistic). The Siamese's eyes are known to be blue or blue, while the Burmese's are golden. These signs are also determined by the action allele th cs and cb. The relationships between these alleles are, so to speak, parity.

Heterozygotes cbcs - the so-called Tonkinese - have a color intermediate between Siamese and Burmese and a specific turquoise eye color.

Two most recessive allele series C produce a defective, non-functional tyrosinase, and homozygosity for them leads to albinism, that is, the absence color, with the only difference being that white sasa homozygotes still have blue eyes, and cc homozygotes have pink eyes. Both of these allele are extremely rare in our cat populations, so when you see a white blue-eyed cat, you can be almost one hundred percent sure that its color is determined by the dominant W gene, and not by homozygosity for Ca.

Locus Color – color (color)

Color - albino allelic series

C>c b =c s >c a >c

C – normal gene / rich pigment

c a - albino blue eye

c - albino pink eye

The mechanism of action of recessive alleles locus Color

Changes the structure of the enzyme tyrosinase, making it thermolabile
Altered tyrosinase stops the synthesis of pigments at temperatures above 36 o C
The cat's body temperature is 37.6 o C - 38.6 o C, the skin temperature of the extremities is slightly lower - 36 o C, while pigment synthesis continues

Scheme of operation of defective tyrosinase

Phenotypic manifestation

c b - Burmese color.
The altered tyrosinase stops the synthesis of pigments at temperatures above 37 o C. At the cat’s body temperature, the pigment is not synthesized in full tone, the points are more intensely colored
c s – Siamese color– acromelanistic colors
The pigment is synthesized only on the points - the end parts of the body (muzzle, ears, paws, tail)
The color of the points is determined by other genes found in the genotype
c a - blue-eyed albinism. Phenotypically similar to dominant white
c – edge With leg-eyed albinism. Mutation lost

Genotypes of cats

C- (the trait replaces any gene in the Color series) – rich pigment
c b c b - burmese, Burmese color or sepia, low-contrast point, golden eye color
c s c s – Siamese, Siamese color, contrasting point color, colorpoint. Eye color bright blue
c b c s – heterozygote – Tonkinese, Tonkinese mink, intermediate contrast of points, turquoise eye color

May mask the effects of other genes color
Colorpoints have bright blue eyes. Golden eye color in sepia - Burmese, aquamarine eye color in heterozygotes - Tonkinese
Convergent strabismus associated with redistribution of fibers in optic nerve and atrophy of the internal bundle of the optic nerve

Dark spots appear on the color point coat when it cools.

Next in the process of being determined color gene B (Black) is responsible for the synthesis of the pigment melanin, which determines okra With; at the same time, its dominant allele forms the normal form of the pigment (black), and the recessive allele forms the oxidized one, i.e. chocolate. Like the C gene, Black has allelic series - in addition to the black and chocolate alleles, there is also the most recessive allele bl, which forms a highly oxidized form of eumelanin. If homozygotes and heterozygotes with the B allele have a black color (or derivatives from its combination with other non-allelic genes: seal point, blue, etc.), then homozygotes for the b allele and bbl heterozygotes have a chocolate color. And finally, cats with the blbl genotype will be a warm reddish-brown color (it is also called cinnamon, and in the Abyssinian breed it has its own name - sorrel).

Locus Black – black, chocolate, cinnamon

Black tabby or Brown tabby

Black-chocolate-cinnamon

B – normal gene

Mechanism of action of genes b and b l
Oxidation of the black form of eumelanin to brown and cinnamon

Phenotypic manifestation

Change of basic colors:

Black - brown, corresponding color of the nose, edging of the eyelids and paw pads;
Black agouti - brown agouti
Blue - lilac
Red in the tortoiseshell color line is lightened to cream or whitish.
On a solid red color the effect is not noticeable

Genotypes

A sex-linked mutation located on the X chromosome, O (Orange), leading to the development of red hair. colors, has already been described in detail in the section on general genetics. Its action leads to a disruption in the synthesis of eumelanin, as a result of which the cells form only a yellow pigment, the amount of which will determine the intensity of the coloring of the cat's fur: from pale red to brick red. Naturally, in tortoiseshell cats with the Oo genotype, the second color will depend on the genetic set of alleles in others loci, and above all in locus B.

The red series consists of only two colors: red and cream (dilution of red). The red color is gender-linked. This means that the locus of this gene is located on the X chromosome, and inheritance of red color carried out through this particular sex chromosome. The red color gene provokes the production of the pigment pheomelanin, as a result of which the cat's fur acquires different shades of red. To the intensity of red color, is influenced by the lightening gene, designated by the letter D (Dilutor). This gene in a dominant state allows the pigment to lie tightly along the entire length of the hair. A homozygous combination of recessive dd genes provokes a sparse arrangement of pigment granules in the hair, diluting the color. This creates a creamy color, as well as clarified variations of tortoiseshells (blue cream and lilac cream).

Red series cats always have an open tabby pattern. The solid red color appears as a result of breeding work, by selecting sires that have the most shaded, blurry tabby pattern.

Orange locus – orange, sex-linked

Orange non orange

o – normal gene

Red color , connected to the floor

The Orange gene is located on the female sex “X” chromosome, which also carries some harmful genes - baldness, hemophilia, etc.
Due to the effect of random inactivation of one of the X chromosomes, both a dominant and a recessive gene appear outwardly in a heterozygous form
When writing the color formula, the X chromosome is replaced by the sign O or o
The symbol of the chromosome that determines male gender - “y”, is preserved

Mechanism of action of the Orange gene

Synthesis of all pigment as pheomelanin

Phenotypic manifestation of the Orange gene - red, sex-linked

In homo- (OO) or hemizygote (Oy) – red color with preservation of ticked hair (pattern development)
In a heterozygote (Oo) - tortoiseshell color (random distribution of red spots mixed with another main color - not red). A few hairs of a different color are considered a spot

Genotypes

Color	Cat	Cat
Non orange - without red Tortoiseshell	oyOy	ooOO

Epistasis and pleiotropic action

In homo- or hemizygote masks the action loci agouti and black
In some cases, choleric character
Reduced blood clotting, increased vascular porosity, may be associated with linked inheritance of hemophilia genes

However, even with the same amount of pigment synthesized by cells, color The color of an animal can be intense, light, as if diluted. The phenomenon of such lightening color This is called Maltesian, or Maltesian, dilution; it is very common in the animal world: we know blue rabbits and blue mice, dogs and minks.

The intensity is determined color a gene called Dilutor (symbol D), that is, a diluent.

Gene D is not responsible for the synthesis of pigment, but for the distribution of its granules in the hair. Pigment cells, under the influence of this gene, form processes that extend into the hair, in which the pigment granules are “packed”, and under the influence of normal allele the processes of melanocyte cells are formed long, and when the mutant allele d - shortened. Simplified result of an action allele D can be defined as the dense arrangement of granules, and allele d - like loose. This arrangement of granules is externally perceived as a weakened, lighter color.
Some felinologists identify another, most recessive allele at the D locus - dm. In cats homozygous for this allele The hairs of the awn are lightened so that they become almost discolored towards the tip. As a result, the blue cat is covered, as it were, with a light silver coating.

An example of this color is the coat of the Russian Blue breed.

By the way, kittens from crossing such individuals and cats with a dark blue coat tone, as a rule, lose their silver tint.

Purple coat color in cats occurs as a result of a combination of recessive alleles two different genes - Maltesian lightening (its genetic symbol is d) and chocolate color(character b). Maltesian clarification, as stated above, is the basis of such colors, like blue (diluted black) or cream (diluted red). However, the mating of a blue cat and a chocolate cat, whose ancestors were of the same color, most likely will not produce not only lilac, but even blue and chocolate kittens, but only black ones. What is the reason for this unexpected result?

First of all, in the recessive nature of each of these alleles. In order for a sign defined by such alleles, manifested itself externally, they must be in a homozygous state, that is, the kitten must receive the same alleles both from father and mother. Lightening of the base color and chocolate tone are inherited independently of each other. From a genetic point of view, the blue cat is homozygous for the pair alleles lightening - dd. But the place of recessive alleles for chocolate color is taken by dominant alleles of the same gene, designated B (Black). Thus, a blue cat descended from the same ancestors must carry a pair of dominant alleles - BB.

The chocolate cat has the reverse genotype - DDbb. Since during the formation of germ cells exactly half of the genetic information gets into them, each parent passes on to their offspring only one allele from each pair. Consequently, the genotype of kittens will contain one dominant and one recessive allele genes D and B, Dd Bb, of which only dominant ones will appear - and all descendants will be black.

Of course, if you cross these black descendants - carriers of traits - with each other, among their kittens, along with black ones, you can find blue, chocolate, and even lilac, although the number of the latter will be the smallest. This is a situation of classical dihybrid splitting according to Mendel.

A similar picture will be observed in the case when the dd dilution alleles are combined in the cat’s genotype with alleles cinnamon color- blbl. Such individuals will acquire a soft beige coat color, bearing the felinological name “fawn”.

Lilac and beige, as well as chocolate and cinnamon colors, are common among cats of Oriental, Siamese, Burmese and related breeds, such as the Ocicat. But in the Persian, British and European breeds these colors, although included in the standard, are far from common. Apparently allele chocolate color was brought to Europe with cats of Eastern origin and was later introduced into the established breeds of the West.

Among outbred cats in Moscow, chocolate and lilac cats are extremely rare. Their ancestors may have included traditional Siamese (now called Thai) cats carrying allele b in a latent, heterozygous form.

For a long time, two rare colors found in cats of eastern origin remained a mystery to breeders - the so-called fawn and caramel. Fawn can be described as a warm golden brown, while caramel is a lighter, milkier modification of the former. It is currently believed that both of these colors are caused by the action of the dominant Dm gene, a lightening modifier that acts only if the cat’s genotype contains diluent alleles d.

The fawn is formed with the participation of the Dm allele against a background of blue color, that is, with the B-dd genotype, and caramel is formed against a background of lilac, with; genotype bbdd. The exact mechanisms of operation of this gene remain unclear.

Locus Dilution - dilution (Maltesian clarification)

Dark-dilution-dilution modification

D – normal gene

Lightener = Malthusian lightening

The mechanism of action of recessive alleles locus Dilution

d - deformation of discs in the medula of the integumentary hair

Conglomeration of pigment into clumps

Formation of voids in the hair shaft

d m - depigmentation of the hair tip

No epistatic effect noted

Increased number of anomalies in weakened cats colors

Phenotypic manifestation

Lightening the main colors :

Black - blue, change in color of the nose, edging of the eyelids and paw pads to slate gray;
Red - cream
Brown - lilac
Cinnamon - caramel, beige, deer
d m – “silver coating” in the “Russian Blue” and “Nibelung” breeds

Genotypes of cats

Cats can be monochromatic, or those in which both pigments – black (or its derivatives) and yellow – are mixed. Moreover, if you look closely, they are not mixed in some way, but forming alternating stripes on each hair - the so-called ticking.

Determines the presence of ticking dominant gene locus agouti- A (Agouti), which got its name from a South American rodent with an excellent color. In addition to ticking, cats with group colors agouti have two more characteristic features - a light mark in the shape of a human thumbprint - on the back of the ear and a pink or brick-red nose, surrounded by a border of the darkest color for a given color colors.

Recessive allele this locus is called “neagouti” (denoted a) and provides a uniform color of the hairs - specifically the hairs, but not necessarily the cat as a whole. That is, a cat with the aa genotype can be black, chocolate, cream, or even have a blue point color - depending on which alleles will be included in the other loci genes responsible for color. It is natural that cats with color agouti the color of the stripes on the hair also depends on the allelic state of the same genes - stripes can alternate between black and yellow, blue and yellowish, brick and light red, and so on.

How can it work? agouti-gene? Probably, alternation of pigment deposition occurs during hair growth according to the principle of a “built-in” biological clock, with periodic switching on and off of gene activity. One can also note the completely different character in the width and number of ticking strips in different cats. In other mammals that have similar colors, such as mice and dogs, agouti is considered a complex, complex genome and is represented not by two alleles, but by extensive allelic series.

Locus Agouti – agouti , neagouti

A - Agouti
a-non agouti

A – normal gene

Mechanism of action of the dominant gene A
"biological clock" principle
alternating switching on and off of gene A prohibits and allows eumelanin synthesis

Mechanism of action of the recessive gene a

Blocks the mechanism of switching domains in the structural part of the gene
Provides continuous synthesis of eumelanin in the hair papilla

Phenotypic manifestation alleles of the locus Agouti

Ticking (zoning) is the alternation of zones of black and red pigments along the length of the hair. The yellow Agouti stripe is an obligatory component of zonal colors
Tipping - intense pigmentation of the hair tip
Characteristic agouti markings on the face, legs and tail
Dorso-ventral distribution. The back is darker than the belly

Creates a uniform color
Complete staining of the nose and crumbs
The back and stomach are painted the same way

Characteristic markings agouti

Dark edging of brick-red nose and eyelids
- Light spot on the back of the ear
- Stripes from the outer corner of the eye, creating a diamond-shaped pattern on the cheeks
- A pattern resembling the letter “M” on the forehead
- Chest necklace
- Ring stripes on limbs and tail
- The rest of the pattern is due to the action of the Tabby locus

Epistatic action of gene a

By erasing the ticking of the hair, it masks the effect of the Tabby locus

Pleiotropic effect of gene a

Type nervous system– sanguine

Increased resistance to stress

If cats with the non-agouti genotype usually have a solid color (not counting acromelanistic and smoky variations), then agouti colors, as a rule, are combined with one or another pattern on the cat’s body. The alleles of the tabby series (T - Tabby) are responsible for the presence and type of such a pattern. Occasionally, however, in natural populations there are cats with pronounced ticking, but practically no pattern. The same color characterizes the Abyssinian cat breed.

Dominant, allele, responsible for the formation of this color, called the Abyssinian or ticked tabby, is designated Ta. However, heterozygotes for this gene, and occasionally homozygotes -TaTa, have residual elements of the pattern: “necklace” rings on the chest, faint stripes on the legs and a mark in the shape of the letter “M” on the forehead.

The most common pattern among Russian cats is the tiger pattern (or mackerel tabby) - that is, vertical stripes on the body in combination with those common to all patterned cats. colors elements: an "M" mark on the forehead, rings on the chest, curls on the cheeks, two rows of double spots along the belly and stripes on the tail and legs. This pattern is determined by the T allele, recessive to Ta. But the marbled color of cats, which is quite rare in our country, but common in Great Britain (includes a “butterfly” on the shoulders, two stripes along the back and streaks on the sides) is characteristic of homozygotes for the most recessive allele Tabby series - tbtb.
The most mysterious pattern remains the spotted one, consisting in its most complete expression of even, equal-sized round or oval spots on the sides (naturally, in combination with elements common to all patterns). When crossing spotted cats with each other, they always produce kittens only with the same pattern and never brindle. There are also no known cases of spotted kittens appearing in merle-colored couples. It would seem that the spotted pattern should be determined by an allele of the same tabby series, recessively inherited in relation to T and dominant in relation to tb, and designated something like tsp. Between brindle and spotted colors all transitional degrees are observed - from stripes broken in several places to almost round spots. There are also known individuals that have 2-3 stripes on the front of the body combined with spots on the back. This could be explained by the intermediate manifestation of the T and tsp alleles. It is interesting that out of hundreds of cats with intermediate brindle-spotted colors, there are literally only a few known with a broken marble pattern! A possible explanation for this phenomenon may be that tabby is a complex, extended locus, within which an exchange of sections of genetic material is possible (intragenic recombination). Another hypothesis about the origin of spotted colors suggests that breaks in brindle color and, as an extreme form of this phenomenon, spotting, are caused by the action of genes from another locus independent of tabby. But the latter assumption also does not explain the quantitative difference between the breaks in the stripes of the tiger and marble patterns.
The mechanism of pattern development is most likely also associated with the internal biological clock of the body’s development. Even in small white kittens, you can notice such a “pattern” formed by stripes of hair of different lengths and textures: longer and coarser ones alternate with thinner and shorter ones.
Probably, the different coloring of the hairs of the pattern (they are darker, painted entirely or with wide stripes of dark pigment) and the hairs of the background (with wider stripes of pheomelanin) is associated with different periods of maturation of hair follicles, different rates of hair growth, and therefore with different periods turning on/off genes responsible for pigment synthesis.

Tabby locus – tabby (picture)

Tabby
drawing
valid only against Agouti background

T a ≥T > t b =t mr > tsp

Abysiner–Tiger–blotched–marble-spotted

T – normal gene

Mechanism of action locus alleys Tabby

Determines the change in the depth of hair tipping, creating a pattern
Like agouti works on the principle of the “biological clock”
Appears only in the presence of the Agouti or Orange gene (“there is no red without tabby”)

Phenotypic manifestation allele T a

Ticked color without pattern on the body
The ticking rings are very small, their number reaches 18
With rich pigment creates a wild color Abyssinian cat - Wild or "roasted" - ruddy
When combined with chocolate (or cinnamon) it creates a sorrel color.
Residual pattern characteristic of agouti, remains on the muzzle

Pleiotropic effect allele T a

Oxidation of black pigment to orange (red not associated with gender)

Ttic>Ttabby
Zonar color without picture

Ttic is a separate locus, distinct from locus Tabby
The main difference from the Abyssinian tabby is that the pigment does not oxidize - “zone gray”
The gene is not only empirically identified, but also mapped to another chromosome
Shows dominant epistasis in relation to the Tabby locus
Widely distributed in cats of non-Oriental origin: European Shorthair, British Shorthair, found in Oriental breeds
Erases patterns in cats of “golden” colors

Phenotypic manifestation of T– Tiger tiger or mackerel

2-3 vertical solid stripes behind the shoulder blade and segmented “broken” stripes on the sides - European version
Narrow transverse rings and half rings on the paws and tail
“Belt” - dark stripe along the ridge

Phenotypic manifestation t b blotched tabby = classic tabby
marbled or classic tabby

Extended stripes forming rings and spirals on the sides
Butterfly pattern on the shoulders
Wide belt along the ridge
Wide stripes in the form of triangles on the paws and tail

Phenotypic manifestation t mr marble, sockets

Splitting of individual stripes and spots with the formation of rings and rosettes
The rosette is a closed or broken ring of dark wool with a clearing in the middle, in the center of which there may be a dark point
Found in the Bengal and Ussuri breeds
The type of inheritance is not fully determined
Conventionally, the gene is considered recessive in relation to Tiger and semi-recessive in relation to blotched tabby

Phenotypic manifestation of t sp
Spotting
spotting or spotting

The pattern consists of clear round spots in the shape of a coin
All stripes of the design are torn, including small stripes on the head and necklace
There are specks on the paws and the upper third of the tail. At the end of the tail there are ring stripes

Gene – stripe segmenter

Hypothetical gene causing brindle stripes to break
Very often, brindle in cats has an intermittent appearance on the rump and sides.
With extreme expression, a color close to spotted is formed, but the stripes on the paws and tail remain unaffected

Nevertheless, there are also mutations that can not only change the entire pattern of alternating black and yellow stripes, but also completely “wash away” the pattern from the cat’s body, despite its agouti genotype. Inheritance of such colors is one of most interesting problems genetics of cats. For many years it was believed that their appearance was caused by the action of the melanin inhibitor gene - I. The recessive allele of this locus - i - does not have any outwardly noticeable effect on pigment synthesis, and the dominant allele of the same gene stops melanin synthesis in such a way that the guard hairs are colored only top part, and the bases of the awn and the undercoat of the cat generally remain intact.

However, it quickly became clear that calling allele I dominant is not entirely correct. The fact is that its expressiveness varies within very wide limits. It was assumed that the activity of the inhibitor gene underlies several groups of colors. On the genetic background of non-agouti - aa - the guard hairs under the influence of this gene are uncolored for almost half the length, and the undercoat remains completely white. This color of cats is called smoky. But smoky colors with poorly bleached, grayish undercoat are often found.

In silver tabbies, colors that develop under the influence of an inhibitor gene based on genotype -A-, the hairs in the pattern are often colored almost to the base, while in the background guard coat only the tips remain colored. Moreover, very often in smoky cats the shadow pattern shows through, and the hairs in it are darker. This phenomenon is especially pronounced in kittens, and small “smokes” are confused with silver tabbies.

The extreme degree of activity of the inhibitor gene is the so-called shaded and shaded colors (chinchillas). These colors also develop on the Agouti genetic background. For the former, the tip of the hair is dyed approximately 1/3 of the length, and for the latter - only 1/8, without any stripes. This distribution of color throughout the hair is called typing. Naturally, the color of the hair tips depends on which alleles are contained in the B, D and O loci. The word "cameo" is added to the color names of shaded and shaded cats with red or cream hair tips.

The described variations in the manifestation of the melanin inhibitor give reason to assume a much more complex picture of gene interaction than the influence of only one allele I. Moreover, golden ones have been added to the silver group of colors associated with processes of partial disruption of pigment synthesis.

The first and main sign of golden color: from 1/2 (golden tabbies) to 2/3 (golden shaded) or 7/8 (chinchillas) part of each guard and cover hair is colored in a light or bright apricot, warm tone. The shades of this tone in different parts of the cat’s body may vary, but in no case should they turn into dull, grayish colors. The most common (not to say pleasant) addition to the color of golden tabbies and golden shaded cats are residual ticking stripes on the darkly colored part of the guard hairs, which either “smudges” the pattern (in tabbies) or gives a sloppy appearance to the color (in shaded cats). . This deficiency is so common that it is considered almost the norm.

It is extremely common to find color variations of cats, intermediate between golden and ordinary black tabbies: the guard hairs of such animals are painted “gold”, but the undercoat is gray. Usually the eyes of these individuals do not reach the emerald green color characteristic of golden colors.

Among golden cats with a pattern (tabby), there is another variation of the golden color - when both the undercoat and the background of the coat are well lightened, but the outer hairs in the pattern are darkened almost to the roots. In cats of this type, there are no ticking stripes in the pattern, and the “gold” itself is an intense, almost copper color, which is a clearly positive quality. Unfortunately, the sample of cats of this latter type is extremely small. So, among the golden colors, at least three different types can be distinguished, as well as all the transition options between them.
This is the first time a litter of golden chinchilla cats has been produced from silver chinchilla parents. Therefore, it was initially believed that the golden color is determined by the presence of the same semi-dominant inhibitor gene (genetic symbol I) that provides the silver colors of chinchillas, shaded, tabby and smoky cats.
However, the work of just one gene, even a semi-dominant one, could not explain all the color variations obtained in the silver-gold range. Therefore, geneticists have suggested the genes of rufism - that is, a group of genes that provide additional synthesis of the yellow pigment - pheomelanin. But this too vague assumption was not considered satisfactory.

Although not the most perfect manifestations, golden color is quite common in cat populations. The search for the genes responsible for such a seductive color continued. Researchers first of all paid attention to the so-called “Vavilov series,” that is, the similarity in color mutations in different groups of animals: for example, Siamese cats, Himalayan rabbits, and acromelanistic mice - they all have the same genetically determined color.

According to this law of parallelism, the dominant “broad stripe” gene, Wb, found in some rodents, was put forward as candidates for golden color genes. Under the influence of this gene, a wide yellow stripe is formed at the base of the hair, and the animal acquires a golden color. In the case of the normal allele of the wb gene, the result is an ordinary black tabby, but if an inhibitor gene is added to this genetic background, then a silver tabby is formed.
When alleles I and Wb are concentrated in one organism, silver or shaded chinchillas are formed. Another hypothesis, also based on the parallelism of colors, is the presence in cats of the “golden agouti” gene (genetic symbol Au), characteristic of dogs and mice. In most well-studied genetically mammals, the agouti complex is represented not only by two alleles, that is, gene variants known in cats (A - agouti and a - non-agouti), but by a whole series of alleles. The so-called “sable” color of dogs, for example, is associated precisely with the effect of the “golden agouti” allele and consists of a yellow coloration of the hair (with the exception of its dark ends). If we proceed from the assumption that the same gene is present in cats, then further discussions about the formation of the silver-gold color range will be similar to those outlined above, with the difference that the place of the hypothetical recessive wb will be taken by the usual agouti factor Au.
Currently, the most common bigenic theories for gold and silver colors, that is, based on two separate loci (or genetic complexes).

To get acquainted with one of the latest theories of inheritance of golden and silver colors, based on the interaction of two independent genes against the background of agouti or non-agouti mutation, we should recall some features of breeding not only these, but also smoky colors:

when crossing golden tabbies or shaded cats with each other, no silver offspring appears, while the appearance of golden shaded silver chinchillas when crossing silver chinchillas is a fairly common case;

Silver cats with a pattern when crossed can produce golden offspring only if the silver of the parents is not of sufficient quality - there is yellow ticking in the pattern, yellow overflowers on the face and other color defects;

during inbred breeding (inbreeding of cats with a pronounced golden color, golden offspring are born (sometimes lightened ones are produced); ·

When unrelated crossings of golden cats, as well as when crossing them with silver ones, among the golden descendants there are often kittens with gray and brown undercoat, and among the silver ones - with yellowish ticking along the hairs and yellow overcolors on the face and paws; ·

when crossing golden cats with black tabbies, all the offspring, or at least half of them, are ordinary black tabbies, but offspring of intermediate colors are also found, and in such individuals the undercoat is usually gray, and the “gold” is noticeable only in the guard hairs; ·

in unrelated crossings of smoky cats with each other or with monochromatic cats, offspring with a light gray “cold” undercoat often appear;

on the other hand, among monochromatic cats there are often individuals with a warm reddish overcolor on the coat and the tone of the undercoat.·
It remains to be assumed that the genes responsible for the silver color (inhibitors of melanin, and especially its yellow modification - pheomelanin) act independently of the genes of the golden color - inhibitors of eumelanin, black pigment (the fact that the golden color gene is also a pigment inhibitor is indicated by correlation of color with green - undercolored - eye color). In one of the latest works, these genes were named Bleacher and Eraser respectively (the name and genetic symbols are unofficial). Each of these genes must be represented by at least two alleles, acting naturally on an agouti or non-agouti background.

It is conventionally accepted that these genes have the same genetic activity. In reality, of course, the relationships between dominance and recessivity are not observed so strictly and the expression of genes varies over a fairly wide range, as evidenced by the often observed intermediate color forms.

Locus Inhibitor – tipped colors

Melanin Inhibitor

Inhibitor (I) = Bleacher or Bleaching (Bl) = Silvering (Sv)
Effective against Agouti, non agouti and Orange

i – normal gene

The dominant allele of this gene stops pigment synthesis at a certain stage of hair development

Widebanding
A group of genes encoding the width of the bleached part of the hair
Valid only against Agouti background

wb – normal gene

In the absence of an Inhibitor, the basal yellow stripe expands

With Inhibitor erases ticking and expands the white root zone

Additional modifier genes for typed colors

Gene U - erases the pattern from the body, leaving stripes on the limbs, similar to the Abyssinian tabby
A group of polygenes - getting rid of the residual pattern
Gene Confusion (disorder) – lack of coordination in the size of hair typing
Gene “Chaos” (Chaos) - shades dark stripes and darkens light ones

It is known that the degree of expression of a gene often depends on its dose, that is, the number of copies.

That is, a homozygous silver cat will have more pronounced “silver” than a heterozygous cat. In this case, one should take into account the ability of genes to double and increase their copy number as a result of mutations. Naturally, desirable color combinations are immediately fixed by breeders, and thus the number of copies of the gene in the population or nursery increases. As for the genes-modifiers of rufism, their role is now defined as factors that modify the intensity of the yellow pigment - from pale golden to bright copper. Probably, their effect is associated either with the intensity of pheomelanin synthesis, or with the degree of its concentration in the hair follicles.

Peculiarities of breeding work with color groups

At best, breeders try to solve the problem of improving color in parallel with improving the type of animal, coat texture, etc. Only for some breeds that are close in morphology to the natural type, such as European, Egyptian Mau, Bengal, Ocicat, the problem of improving color comes to the fore. When working with breeds of extreme appearance - Persians, Orientals - the quality of color is often sacrificed to improve the type. In order to consciously improve color, it is necessary to limit breeding work to the framework of this color. Otherwise, color loses its significance as a selective trait, that is, it is impossible to select and select sires based on its indicators.

Most large foreign catteries, as a rule, specialize in breeding cats of two to four colors that combine well with each other. Russian breeders, especially in the periphery, are often faced with a situation where breeders of the breed type in the desired color are not in the population and it is impossible to select the right pairs. Not so long ago, compatibility tables were very common in Russian clubs, showing the possibility of mating between manufacturers different colors, in order to avoid obtaining a breeding marriage. However, in recent years, with the recognition of standards for a number of “new” colors, the concept of color compatibility has largely lost its relevance. Of course, when breeding cats of any color, you won’t get transparent kittens - they will be some color. But numerous matings of “any with “any” have already managed to lead to the appearance of such persistent coloristic defects as a violation of the distribution of colors in bicolors, insufficiently pronounced “smoke”, ticking in chinchilla colors, etc. In the cameo group, experts “change” animals from color to color at each exhibition - and what can be done if the color of these cats is intermediate: either hot cream, or light red, and the degree of expression of silver is uneven across the body.
Due to the requirements for the quality of colors, some kind of compromise solution seems necessary. Unfortunately, our breeders are too prone to unjustified generalizations and have excessive trust in the printed word. A number of guides provide very specific recommendations for color combinations. And they are derived, as a rule, on the basis of some particular results obtained by the author.
In reality, these recommendations have almost no universality, and by automatically applying them to your nursery, you can get the opposite result to the desired one. If for some reason the breeder cannot limit work in the nursery to one or two colors, when selecting color pairs it is advisable to take into account the following points:

matching the eye color of the parents for those breeds in which the eye color is strictly standardized and corresponds to the colors (Persian, British). Since the inheritance of eye color in cats is determined by a complex polygenic system, matings between orange- and green-eyed sires turn out to be quite risky. Of course, this rule can be applied to white color only in the sense of the incompatibility of copper and green eyes, but not copper and blue.
In relation to Himalayan colors (colorpoints), this rule has specific application. The blue or blue color of the eyes of color-points is, of course, determined by the action of the cs allele, but the shade of this color correlates with the original yellow or green eye color of the parents. Light tones correspond to orange or copper, sky blue to yellow, dark violet to green;

give preference to those sires whose ancestors or descendants had a high-quality color of the same type as the intended partner. For example, the color ratio and distribution of white spots in bicolors are regulated not by the S allele itself, but by groups of modifier genes. We can only guess in what allelic state these genes are in a monochromatic cat and what the number of white spots will be in his descendants from white-piebald cats. Therefore, if a bicolor cat is supposed to be mated to a monochromatic cat, then there is a greater chance of getting a obviously good color ratio in the kittens if the cat’s mother or father had a high-quality bicolor color. It is with this in mind that breeders select pairs for nurseries if they plan to carry out breeding work with several colors. Moreover, since the work is carried out using repeated related matings, the state of the genes required for high-quality coloration turns out to be stable. Only in this way can groups of animals with consistently compatible colors be created.

White color

Almost the only color whose quality does not suffer when mated with any partners. If there is a possibility of deaf kittens (due to deafness in the cat or in her ancestors), it can be recommended to lower the dose of the gene by choosing a colored cat. Only if the animal’s residual color spot on its head has not gone away for a long time or has not gone away, it is necessary to breed it with a white partner.

Such a defect as mosaicism of eye color in white cats (half of the eye is blue, half is yellow) does not depend on the color of the parents and is observed both in the offspring of pure white and mixed pairs.

Black color

It is quite difficult to achieve good quality of this color in representatives of breeds with a well-developed undercoat. Lightened, gray or reddish, rusty tones often clog the color. When mating black cats with individuals of blue and lilac color, it should be remembered that particularly light colors are dangerous precisely because they lighten the undercoat of black offspring.
Naturally, it is better not to associate blacks and blue cats with the same “rust” color. Cats with warm chocolate and lilac colors, as well as tabby colors in warm or “golden” tones, are undesirable for mating with black individuals, since these mating options are fraught with the appearance of reddish tones in black offspring.

Blue color

In order to obtain good light blue colors, it is advisable to carry out breeding work, if not exclusively in blue color, at least in the group of lightened colors - lilac, cream. At the same time, lilac should not have a warm tone, and cream should not be “hot” (that is, have residual ticking). A warm tone produces “rust” in a blue color, and ticking is just as successful in polluting a blue color as it is in a cream color. Sometimes it is possible to select related groups (in the optimal case, lines) of intensely colored cats that give good bleached colors.

Chocolate and lilac colors

The main requirement for the quality of these colors is warm tones. They go well with each other, and as more or less desirable partners we can recommend intense red and cream cats (but without a pronounced residual pattern or ticking in the color!), and for chocolate and lilac tabbies - golden cats with a pattern.

Red and cream colors

These colors are difficult in that their background very often retains a pronounced pattern or ticking in the absence of the agouti factor, so that it is sometimes difficult to tell by the appearance of the animal whether it is a red tabby or just red.

This can be established by the offspring of matings with cats of the same color, however, such matings are not always desirable - the consequences of such crosses in tortoiseshell color are especially unpleasant: in the areas occupied by red, the pattern is clearly visible, and the rest of the body remains purely black. The preservation of the residual pattern in red and cream Neagoutis is more pronounced the less undercoat they have. The only way to overcome this coloristic feature is the breeding of red and cream cats only in this group of colors, in combination with selection and inbreeding with inbreeding for sires that have no pattern or with minimal expression of it.

Tortoiseshell colors

Selecting for the distribution of spots in tortoiseshell colors is a rather dubious task. For the most part, the inactivation of the X chromosome leading to this type of coloration occurs by chance. In the offspring of individual female kittens, however, one can notice some similarity with the maternal type of distribution of color spots, so perhaps there are some sex-linked genes that limit the timing of inactivation or selectivity in turning off one or another chromosome. However, if the tortoiseshell color of a cat is determined by the red color of its father, there is no point in trying to select for the quality and ratio of color areas.

Smoky colors

The main indicators of the quality of smoky colors are the uniformity of the smoke, that is, the uncolored part of the hair, and its contrast. Of course, it is better to breed smoky cats separately from monochromatic cats. However, as with the blue color, it is possible to select related groups of monochromatic individuals that have the allelic state of the eumelanin inhibitor modifiers necessary to produce quality smoke.

Bicolors and harlequins

The above situation is also suitable for bicolor colors. In the case of breeding harlequins and bicolors in the same breeding group, you should pay attention to the dose of the gene. So, for bicolors with insufficiently developed pezhins, you can select harlequin partners, and, for example, for bicolors with a single splash of white on the back, you should select bicolors with the correct color distribution.

Although most felinologists recognize the S gene as dominant, and bicolors as heterozygotes for it (Ss), nurseries are known that consistently reproduce bicolored animals without systematically separating harlequins and monochromatic individuals.

Obviously, with systematic selection and linear breeding, this gene is quite amenable to stabilization. White piebald type Van is somewhat isolated from other particolor colors.

It is recommended to breed cats with this type of distribution of white spots without using other white-piebald and even more so single-color variations in order to avoid the appearance of colored spots on the back, staining of the ears and other color defects. The stability of inheritance of Van white piebald is also indicated by the existence of a breed bred only in this color.

Tabby

The easiest to breed is the marbled color. Although it comes in a variety of designs - wide or narrow, bordered or unbordered - virtually all of these variations meet the requirements of the standard.

Ticked Tabby

In most breeds it is not a desirable color, although it is quite easy to breed.

Abyssinian tabby

The highest expression of ticked, completely devoid of pattern - also easy to maintain. The only danger comes from unrelated crossbreeding. Since the absence of stripes on the legs and tail is the result of the action not so much of the Ta allele itself, but of the modifiers accompanying it, when crossing individuals from different populations, the effects of a shadow (fuzzy) pattern on the limbs occasionally occur.

Brindle and spotted

Brindle and spotted, the types of patterns are inconvenient due to their tendency to mutual transitions. In order to maintain this or that pattern in its maximum expression, it is necessary to breed cats of a given color “inside” or select marble partners for them, but not to mix these two types of pattern.

Colorpoint

The quality of acromelanistic colors, that is, the contrast of markings and body color, depends not only on the temperature regime and hormonal characteristics, but is largely hereditary. Often, in one litter, among month-old kittens of the same color, you can find both clearly contrasting and “blurred” variants. This deficiency is especially common in blue and tortoiseshell animals. To overcome it, it is better, of course, to limit breeding work to a group of colorpoints and not to use fully colored cats in matings, among which there may be carriers of modifier genes that darken the point color.

Golden and silver chinchillas and tabbies

As a recommendation, breeders of these complex colors can be advised, for the purpose of coloristic stability, to adhere to moderately inbred matings of those animals whose type of golden or silver color matches, with the exception of the characteristics of Rufism. Of course, within reason, you should not “improve” color-cluttering ticking or gray undercoat, and if you try to correct these shortcomings, then only by mating with an individual that currently has a minimum of such shortcomings. However, any inbreeding that lasts too long leads to a loss of progress in the breed. Therefore, when selecting unrelated pairs, it makes sense to again pay attention to the similar type of “gold” in the intended parents of the kittens.

Cameo, red and cream-silver tabbies

This is perhaps one of the most difficult color groups in breeding work. They combine the characteristics of red colors with their residual ticking with the difficulty of maintaining even typing in silver chinchillas. The recently recognized red and cream-silver tabbies have not only not simplified, but even complicated the situation in this group. It is extremely undesirable to breed red-silver tabbies with shaded or shaded cameos, since the requirements for these colors are exactly the opposite: tabbies must have the clearest possible pattern, and cameos must have even typing. In principle, you can use smoky cats when mating with cameo, but it is necessary to select sires with the most contrasting, evenly developed “smoke”. In any variants of crosses in this group, it is necessary to monitor the development of the color of the descendants of each pair, so as not to repeat unsuccessful combinations.

RED AND BLACK

OO - red

Oo – black

Oo – tortoiseshell.

AGOUTI AND NON-AGOUTI

COLORS OF THE RED SERIES

Two long-haired parents cannot produce a short-haired kitten.
Only the parents' colors determine the color of the kitten. The colors of other cats present in the pedigree do not have a direct effect on the color of the kitten.
A cat kitten always gets its color from its mother.
A cat kitten always receives a color that is a combination of the colors of the father and mother.
To produce a genetically red or genetically cream female kitten in a litter, the father must be genetically red or genetically cream, and the mother must also have a red or cream color in her genotype.
Dominant characteristics (dominant colors: white, silver, tabby, bicolor, etc.) cannot skip a generation. They cannot pass, for example, from grandfather to grandson, without manifesting themselves in the father.
A dominant colored kitten (black, red, tortoiseshell, etc.) must have a dominant colored parent.
Two parents of a recessive color (cream, blue, etc.) cannot produce a kitten of a dominant color (black, red, tortoiseshell, etc.)
A white kitten must have a white parent.
A kitten with a white undercoat (veiled, shaded, smoky) must have a parent with a white undercoat.
A veiled/shaded kitten must have at least one parent who is either veiled/shaded or a tabby.
A veiled/shaded parent can produce a smoky kitten, but a smoky parent cannot produce a veiled/shaded kitten.
A tabby kitten must have at least one parent who is either veiled/shaded or tabby.
A brindle tabby kitten must have a brindle tabby parent.
A spotted tabby kitten must have a spotted tabby parent.
Multi-colored individuals (tortoiseshell, blue-cream, calico, tortoiseshell and white, tortie-point, etc.) are almost always cats, but they can dress up and sometimes give birth to cats.
A bicolor kitten must have a bicolor parent.
Two color-point parents cannot produce a non-color-point kitten (see point 8).
It is possible to get a Himalayan kitten only if both parents are carriers of the Himalayan color (even if they themselves are a solid color).
If one parent is of the Himalayan color, and the other is not and is not even a carrier of the Himalayan color, then not a single kitten of the Himalayan color can be in the offspring.

COLORS

Black dominates Blue

FORMATION OF COLOR

Take on a spindle-shaped shape appropriate for migration and travel to the hair follicles.
Migrate to the centers of pigmentation, which are located in cats on the crown, back, withers and at the root of the tail. (These centers are clearly indicated by the colored areas of the coat in Van cats.)
Penetrate the hair follicle before its final formation. And only after that they become full-fledged pigment-producing cells - melanocytes.

d - the main color is weakened.

w - the presence of color determined by the genetic formula of the animal. W>w.
Wb locus (Wideband).

TABLE OF COLORS OF KITTENS

Main color
(w) White - white
(n) Black, Seal – black
(b) Chocolate – chocolate (dark brown)
(o) Cinnamon – cinnamon (light brown)
(d) Red - red
(a) Blue - light blue
(c) Lilac – lilac
(p) Fawn – fawn (beige)
(e) Cream - creamy

(f) Black Tortie (black with red)
(h) Chocolate Tortie – chocolate turtle (dark brown with red)
(q) Cinnamon Tortie (light brown with red)
(g) Blue Tortie – blue tortoise (blue-cream color)
(j) Lilac Tortie – lilac tortoise (lilac-cream color)
(r) Fawn Tortie – fawn tortoise (beige with cream)

Availability of silver
(s) Silver - silvery

Degree of white spotting
(01) Van
(02) Harlequin - harlequin
(03) Bicolour - bicolor
(09) Little White Spots

Tabby drawing
(22) Classic tabby – marbled
(23) Mackerel tabby – brindle
(24) Spotted tabby - spotted
(25) Ticked tabby - ticked

Point color type
(31) Sepia – Burmese
(32) Mink – Tonkinese
(33) Point – Siamese (color-point)

Elementary rules of genetics of cat colors

Two long-haired parents cannot produce a short-haired kitten.
Only the parents' colors determine the color of the kitten. The colors of other cats present in the pedigree do not have a direct effect on the color of the kitten.
A cat kitten always gets its color from its mother.
A cat kitten always receives a color that is a combination of the colors of the father and mother.
To produce a genetically red or genetically cream female kitten in a litter, the father must be genetically red or genetically cream, and the mother must also have a red or cream color in her genotype.
Dominant characteristics (dominant colors: white, silver, tabby, bicolor, etc.) cannot skip a generation. They cannot pass, for example, from grandfather to grandson, without manifesting themselves in the father.
A dominant colored kitten (black, red, tortoiseshell, etc.) must have a dominant colored parent.
Two parents of a recessive color (cream, blue, etc.) cannot produce a kitten of a dominant color (black, red, tortoiseshell, etc.)
A white kitten must have a white parent.
A kitten with a white undercoat (veiled, shaded, smoky) must have a parent with a white undercoat.
A veiled/shaded kitten must have at least one parent who is either veiled/shaded or a tabby.
A veiled/shaded parent can produce a smoky kitten, but a smoky parent cannot produce a veiled/shaded kitten.
A tabby kitten must have at least one parent who is either veiled/shaded or tabby.
All red cats have some degree of tabby. The ability to produce tabby offspring depends on whether the red cat (or tom) is a true tabby, i.e. does she have a tabby or veiled/shaded parent, or is she just a red cat with a pronounced tabby pattern.
A red tabby, unless it is a true tabby, cannot produce a tabby offspring of any other color unless it is bred to a true tabby (or a veiled/shaded one).
A brindle tabby kitten must have a brindle tabby parent.
A spotted tabby kitten must have a spotted tabby parent.
Multi-colored individuals (tortoiseshell, blue-cream, calico, tortoiseshell and white, tortie-point, etc.) are almost always cats, but they can dress up and sometimes give birth to cats.
A bicolor kitten must have a bicolor parent.
Two color-point parents cannot produce a non-color-point kitten (see point 8).
It is possible to get a Himalayan kitten only if both parents are carriers of the Himalayan color (even if they themselves are a solid color).
If one parent is of the Himalayan color, and the other is not and is not even a carrier of the Himalayan color, then not a single kitten of the Himalayan color can be in the offspring.

RED AND BLACK

OO - red

Oo – black

Oo – tortoiseshell.

Cats have one X chromosome and, depending on which gene it carries O or O, it will be red or black. Tortoiseshell coloring in cats appears only in the case of genetic mutations.

AGOUTI AND NON-AGOUTI

COLORS OF THE RED SERIES

As noted above, red series cats always have an open tabby pattern. The solid red color appears as a result of breeding work, by selecting sires that have the most shaded, blurry tabby pattern.

SILVER AND GOLDEN COLOR GROUPS

Smoky cats of the black series have the genotype: aaB-D-I-.

Red silvers have the genotype D-I-O(O). Red smokes can be genetically either agouti or non-agouti.

ELEMENTARY RULES OF GENETICS OF CAT COLOR

Two long-haired parents cannot produce a short-haired kitten.
Only the parents' colors determine the color of the kitten. The colors of other cats present in the pedigree do not have a direct effect on the color of the kitten.
A cat kitten always gets its color from its mother.
A cat kitten always receives a color that is a combination of the colors of the father and mother.
To produce a genetically red or genetically cream female kitten in a litter, the father must be genetically red or genetically cream, and the mother must also have a red or cream color in her genotype.
Dominant characteristics (dominant colors: white, silver, tabby, bicolor, etc.) cannot skip a generation. They cannot pass, for example, from grandfather to grandson, without manifesting themselves in the father.
A dominant colored kitten (black, red, tortoiseshell, etc.) must have a dominant colored parent.
Two parents of a recessive color (cream, blue, etc.) cannot produce a kitten of a dominant color (black, red, tortoiseshell, etc.)
A white kitten must have a white parent.
A kitten with a white undercoat (veiled, shaded, smoky) must have a parent with a white undercoat.
A veiled/shaded kitten must have at least one parent who is either veiled/shaded or a tabby.
A veiled/shaded parent can produce a smoky kitten, but a smoky parent cannot produce a veiled/shaded kitten.
A tabby kitten must have at least one parent who is either veiled/shaded or tabby.
All red cats have some degree of tabby. The ability to produce tabby offspring depends on whether the red cat (or tom) is a true tabby, i.e. does she have a tabby or veiled/shaded parent, or is she just a red cat with a pronounced tabby pattern. A red tabby, unless it is a true tabby, cannot produce a tabby offspring of any other color unless it is bred to a true tabby (or a veiled/shaded one).
A brindle tabby kitten must have a brindle tabby parent.
A spotted tabby kitten must have a spotted tabby parent.
Multi-colored individuals (tortoiseshell, blue-cream, calico, tortoiseshell and white, tortie-point, etc.) are almost always cats, but they can dress up and sometimes give birth to cats.
A bicolor kitten must have a bicolor parent.
Two color-point parents cannot produce a non-color-point kitten (see point 8).
It is possible to get a Himalayan kitten only if both parents are carriers of the Himalayan color (even if they themselves are a solid color).
If one parent is of the Himalayan color, and the other is not and is not even a carrier of the Himalayan color, then not a single kitten of the Himalayan color can be in the offspring.

DOMINANT AND RECESSIVE CHARACTERISTICS

Black dominates Blue

Black dominates Chocolate

Chocolate dominates Lilac

Chocolate dominates Light Brown

Red dominates Cream

White is dominant over all other colors

Tortoiseshell is dominant over Bluish-cream

Tortoiseshell and White (Calico) is dominant over Tortoiseshell and White (Bluish-cream and White)

The solid color is dominant over the Siamese

The solid color is dominant over the Burmese

Siamese dominates Albino with blue eyes

Variegated (almost white) dominates Solid color

Tabby with Ticking dominates Black

Ticking tabby (agouti) is dominant over all tabby varieties

The Brindle Tabby is dominant over the Marbled Tabby

White spotting dominates Solid color

Albino with Blue Eyes dominates Albino with Pink Eyes

The white undercoat dominates the solid color

FORMATION OF COLOR

The color of the coat depends on the type of pigment, the shape of the pigment granules and their distribution throughout the hair. Pigments perform a variety of functions in the body. They play an important role in cellular metabolism and visual reception, provide coloration to various organic structures and color adaptation of the integument to the external environment.
Today there is an amazing variety of cat colors. Some of them were inherent to them initially, others were obtained, developed and consolidated by restless breeders. But if you look at it, there are very few primary colors on which this entire palette is based. These are: black, blue, brown, lilac, chocolate, beige, red, cream, yellow. Of course, there is also white, but due to the fact that it is not a color, but quite the opposite - its absence, it is called a color symbolically.
The color of the coat depends on the type of a very complex substance in its composition - the melanin pigment, which creates a particular color. Melanin is produced in specialized cells called melanocytes. The source for its formation is the amino acid tyrosine (entered into the body with food). Through biochemical processes, tyrosine is converted into pigment. With the help of a protein catalyst called tyrosinase.
Information about the amino acids that make up tyrosinase is contained in a gene known as Colog - color. There are only four pigments in the cat world. The two main, basic pigments are eumelanin and pheomelanin. They exist in the form of pigment grains (mylanosomes) of various shapes.
The perception of color depends on the refraction of light passing through or reflecting from them. The granules form a somewhat elongated ellipsoidal or spherical shape and can vary widely in size.
Eumelanin is presented in three modifications: black pigment - eumelanin itself and two of its derivatives - brown and cinnamon pigments (mutant form of eumelanin).
Eumelanin granules give the hair high mechanical strength, which affects the elasticity of black wool. This pigment is very stable: insoluble in organic solutions and resistant to chemical treatment.
Pheomelanin granules are characterized by a classic yellow or orange color. Unlike eumelanins, they have a much smaller, spherical shape.
The scale-like structure of the cells of such hair is much less durable than the structure of cells containing eumelanin. And also, unlike eumelanin, which is present not only in hair, but also in skin, pheomelanin is present only in hair.
The process of color formation is called pigmentogenesis. It begins in the embryonic stage of development of the embryo, in the area of the neural tube, from where the anlage of future pigment cells is released, which, in order to gain the ability to produce pigment, must undergo a number of changes:

1. Take on a spindle-shaped shape appropriate for migration and go to the hair follicles.
2. Migrate to the centers of pigmentation, which are located in cats on the crown, back, withers and at the root of the tail. (These centers are clearly indicated by the colored areas of the coat in Van cats.)
3. Penetrate the hair follicle (follicle) before its final formation. And only after that they become full-fledged pigment-producing cells - melanocytes.

But everything will happen only if the gene for the dominant white color is represented in the cat by two recessive alleles (ww). If this gene is represented by at least one dominant allele W, the cells, losing the ability to migrate, remain in place and do not reach the centers of pigmentation; As a result, they do not have the ability to produce pigment, they will remain uncolored, that is, white.
Next, a complex biochemical process continues, the end result of which is the color of the cat. This process depends on the degree of influence and relationships of the simultaneous action of dozens of genes. In order to write down the minimum genetic formula of color, it is necessary to use almost the entire Latin alphabet, even if it does not contain the factors that determine the length, thickness and density of the coat, and there are many other characteristics on which the color of the coat depends.
After all, even two, at first glance, absolutely identically colored cats can have different genetic formulas and vice versa. The rules of inheritance of cat colors are currently considered the most studied and controlled.
Knowing them is necessary for breeders to correctly and competently plan breeding programs for their animals in order to obtain colors in the offspring that meet recognized standards.
A complex of genes is responsible for a cat's color. These genes can be divided into three main groups: the first includes genes that control coat color, the second those that affect the intensity of color expression, and the third determines the location of the pattern or its absence. Although each of these groups works in its own direction, there is a close relationship between them.

Loci responsible for color.
Locus A “agouti” - (agouti). The locus is responsible for the distribution of pigments along the length of the cat's hair and body.
The pigments eumelanin and pheomelanin form alternating stripes on each hair, the so-called “ticking”. Cats with agouti colors are characterized by the presence of a light mark in the shape of a human thumb print on the back of the ear, as well as a pink or brick-red nose, bordered by a narrow dark stripe.
A - promotes the formation of wild color.
a - “not agouti.” Under the influence of this allele, pigments are evenly distributed along the length of the hair. The hair of short-haired cats is colored evenly from base to end, while in long-haired cats there is a gradual decrease in color intensity towards the base of the hair. In small kittens, in bright light, you can detect a slight trace of a mottled pattern against a dark background, which disappears in an adult animal.
Black, chocolate, brown and blue cats have solid color, determined by the aa genotype.
Locus B (Blask). As in other animal species, it is responsible for the synthesis of eumelanin.
B - black color. b - brown (chocolate). To denote the dark brown coat color observed in cats homozygous for the b allele, breeders introduced the special term “chocolate color.”
b1 - light brown, the so-called cinnamon color (cinnamon).
Black color is completely dominant over brown, and in brown there is incomplete dominance of the b allele over b1. In cats, brown color is much less common than black, and it is practically absent in natural populations.
Locus C (Color) is a series of albino alleles.
C - ensures normal synthesis of pigments.
cch - silver color. However, R. Robinson does not recognize the existence of this allele in cats.
There is a group of alleles at this locus that causes uneven coloring on a cat's body. Such animals have a dark muzzle, ears, limbs and tail, and a much lighter body. These colors result from the presence of a temperature-sensitive form of tyrosinase, which is involved in the synthesis of melanin. At normal body temperature, the activity of this form of tyrosinase is sharply reduced, which leads to lightening of the color. The reduced temperature of the limbs, tail, muzzle and ears promotes the activation of the enzyme and triggers normal melanin synthesis, which ensures the development of the typical “Siamese” color. Experiments have shown that raising Siamese kittens in the cold leads to the formation of a solid dark color, and at elevated temperatures - a light color. This group includes two alleles cb and cs.
cb - Burmese albino. Homozygous cbcb animals have a dark sepia brown coloration, gradually becoming lighter towards the belly. The head, paws and tail of such animals are much darker.
ss - Siamese albino. Typical Siamese color. Homozygotes csсs have a body color the color of baked milk or lighter, as well as a dark muzzle, paws and tail. Siamese cats have a blue iris.
ca - blue-eyed albino. Cats of the Sasa genotype have white fur, light blue irises and translucent pupils.
c - albino with pink eyes. Its homozygotes also have a white coat color, but the iris is devoid of pigment.
Allele C is completely dominant over all other alleles of the locus. Intermediate dominance is observed between the cs and cb alleles. Csсb heterozygotes are called Tonkinese and have a color intermediate between Siamese and Burmese and turquoise eyes.
The ca and c alleles are recessive to all higher-level alleles, but how they interact with each other is unknown, since they are extremely rare.
Locus D (Dense pigmentation) - intensity of pigmentation.
D - full intensity pigmentation.
d - the main color is weakened.
Due to the gluing of pigment granules, the uniformity of their entry into the growing hair is disrupted, which leads to an accumulation of granule mass in some areas and a deficiency in others. Individuals homozygous for the d allele have a lightened color: blue, lilac, golden. Wild tabby cats have a lighter color while maintaining a warm yellowish tone.
Locus I (Melanin inhibitor). According to R. Robinson, one mutant allele is currently known at this locus.
I - this allele promotes the accumulation of pigment granules at the end of the hair. At the base of the hair, the amount of accumulated pigment is minimal, which looks like complete bleaching of the hair roots. This distribution of pigment throughout the hair is called tipping.
The effect of this allele can be observed mainly on long hair. The manifestation of the effect of allele I depends on the alleles of other loci. Thus, in cats homozygous for a, the effect of allele I is manifested in the appearance of a light or white undercoat. These colors are called smoky. In tabby cats, the light areas become almost white, and the dark hair in the area of stripes and spots synthesizes pigment almost completely. This color is called silver.
In ginger cats, there is a general weakening of pigmentation and discoloration of the undercoat - a cameo phenotype occurs. However, it has now been proven that the expressivity of allele I fluctuates very highly, and therefore it is not entirely legitimate to call it dominant. Maximum expression leads to the accumulation of pigment only at the end of the hair by 1/3 of its length in the so-called shaded ones, and by 1/8 in the shaded ones, or, in other words, chinchillas. The color of the ends of the hair depends on the alleles of the B, D and O loci.
i - normal distribution of pigments in the hair.
Locus O (Orange). The trait determined by this locus belongs to the group of sex-linked ones.
O - located on the X chromosome (sex chromosome), leads to the cessation of eumelanin synthesis.
Homozygous cats and homozygous cats have red color.
The effect of the allele is manifested only in the presence of allele A, allele a is epistatic in relation to O. Therefore, the vast majority of ginger cats have a characteristic striped pattern caused by the T locus (tabby).
o - color determined by the basic genetic formula of the animal. It appears as non-red spots on the body of a tortoiseshell cat, which can be black, blue, striped, etc.
Locus P (Pink eyed) - “pink eyes”.
P - color determined by the basic genetic formula of the animal.
p - cats homozygous for this allele have a characteristic lightened reddish-brown fur color and reddish-pink eyes. The mutation is extremely rare, and the nature of inheritance of this trait has not yet been sufficiently studied.
Locus S (Piebald spotting) - white spotting.
Represented by a series of multiple alleles.
S - presence of white spotting.
Sw - Van color - white with two small spots on the head and a colored tail.
Sp - spotted harlequin color.
s - solid color without white spots.
There is no doubt that, in addition to the main alleles of the locus, a large number of modifier genes are involved in the formation of spotted colors, just as it happens in animals of other species. Many authors believe that the white tips of the paws in breeds such as the Sacred Burmese or the Snowshoe are determined by genes unrelated to the S locus. Their appearance is associated with a recessive allele
Locus T (Tabby). It appears only against the background of allele A.
Allele a is epistatic to T.
T - determines the development of various patterns typical of wild representatives of the genus Felis and the immediate ancestor of the domestic cat Felis Libyca (Libyan cat). These colors are defined as tabby, brindle or mackerel.
Ta - Abyssinian. Named after the breed of cat for which it is most characteristic. The Abyssinian cat, while retaining the stripes on the face, completely lacks a motley pattern on the body. Sparse markings are visible on the front legs, thighs and tip of the tail. The hair has a clearly defined zonation (ticking).
tb - marble. Marbled cats have a characteristic pattern of wide dark stripes, spots and rings. The dark pattern is most clearly visible on the paws, tail and sides of the animal. The tb allele is recessive with respect to T and in a heterozygous state with it, Ttb gives striped coloring.
The Ta allele shows incomplete dominance in relation to the striped color allele T, as well as to the marbled color allele tb. Heterozygotes TTa and Tatb have residual pattern elements - ring stripes on the chest, faint stripes on the legs and “M” shaped markings on the forehead.
Locus W (White dominant). Dominant white color.
W - pure white coat color, resulting from the cessation of pigment synthesis at the very beginning of the chain of chemical reactions. The allele is incompletely expressive, and some kittens have a small dark spot on the head, which very rarely persists in adult cats. It also exhibits incomplete penetrance regarding eye color. Approximately 40% of white cats have blue eyes, and about half of them are deaf.
Blue eye color occurs due to a lack of pigment and the complete absence of tapetum in the iris, and deafness is due to a lack of pigment in the organ of Corti. The occurrence of these anomalies depends not so much on the dose of the gene, but on the presence of modifier genes and the activity of regulatory elements of the genome. Similar phenomena sometimes occur in white cats with residual pigmentation caused by the presence of the S allele. Sometimes such cats
have partially or completely blue irises.
This can be explained by a violation of the formation of melanoblasts during embryogenesis. In very rare cases, the piebald gene causes some degree of deafness.
The effect of the W allele is similar to the effect of the S allele, but its effect on the reproduction of melanoblasts is more serious. Due to the similarity of the effects caused, it was even suggested that the W allele is one of the alleles of the S piebald locus.
w - the presence of color determined by the genetic formula of the animal. W>w.
Wb locus (Wideband).
Variegated cats, descended from heterozygous chinchilla cats, have a lighter shade of coat than regular tabbies. Their appearance suggests that these animals differ from ordinary tabbies by the presence of an additional allele. It is known that in some species of mammals an allele has been found that causes the appearance of a yellowish tint against the agouti background as a result of the expansion of the band of yellow pigment. This allele is called (Wide band). The coloration resulting from the expression of this allele may be called "golden tabby". The decrease in the amount of black pigment caused by this allele, in combination with the effect of allele I, is responsible for the formation of the chinchilla color. There is an assumption about a dominant mode of inheritance of this trait.

Where do tortoiseshell cats come from?
We already know that if both genes in a pair are responsible for the same characteristic, that is, they are completely identical, then the cat will be called homozygous for this trait. If the genes are not the same and carry different traits, then the cat will be called heterozygous for this trait. One of the hereditary characteristics is always stronger than the other. Black is always dominant, it is a stronger characteristic. The lilac color is recessive and is inferior to black. Two variants of the same characteristic located at the same locus, called an allele, can be both dominant, both recessive, or one dominant and the other recessive. The fact that one of the characteristics “recedes” to another does not mean the disappearance of the weaker characteristic. The recessive characteristic remains and is preserved in heredity, in the genotype. At the same time, the phenotype, that is, visible (externally manifested) characteristics, can demonstrate completely different colors. Therefore, in a homozygous animal the genotype coincides with the phenotype, but in a heterozygous animal it does not.
Red and black are located on the same locus on the X chromosome. In this sense, red is a “sex-linked” color. Cats, therefore, have only one gene for color - they can be either black or red. Cats have two X chromosomes and therefore two genes for color.
If a cat has two genes, for example, black, it is homozygous for black and has a black color. If a cat has one gene for black color and the other for red, then it has a tortoiseshell color. Tortoiseshell cats are a very rare exception. In addition to red and black, there are other varieties of tortoiseshell color. The most common is blue-cream, or, more correctly, blue tortoiseshell. Cats of this color have one gene for blue color, the other for cream, as derivatives of black and red, respectively.
Derivatives from the black color are dark brown (seul brown), blue, chocolate (chocolate brown), cinnamon (cinnamon). Lilac is a derivative of chocolate and blue. Fawn is a derivative of cinnamon and blue.
In the case where both alleles are identical in their characteristics, we will be presented with a homozygous cat. If one color allele in a cat is dominant and the other is recessive, then it will show the color of the dominant allele in its phenotype. A pair of heterozygous cats with a dominant coat color can produce offspring with a recessive coat color (but not vice versa!). In a double recessive (for example, lilac color), the phenotype and genotype are the same.
It is often difficult to understand the meaning of the term "sex-linked" in relation to the red color. The main practical significance of this rule is the ability to determine the colors and sex of future kittens from matings of two animals, one of which is red. There is an important rule of genetics that states that cats inherit the color of their mother. The term “weakened” or “loose” or “diluted” is often used to define colors derived from the two main ones. However, this is not always correct. Derivative colors are formed in two ways: by reducing the pigment granules per unit area and by grouping the same number of granules into bunches.
The black color is formed by round pigment granules, which are spaced at an equal distance from each other. The blue color is formed by the same number of pigment granules, but grouped into bundles. Therefore, it is more correct to speak in this case not about “dilution”, but about “grouping”.
The development of a chocolate (brown) color is an example of true dilution. Black pigment granules are elongated into ellipses. There are fewer granules per unit area.
Of the two sex chromosomes, only the X chromosome determines whether a cat will be black or red. Therefore, we can say that the Y chromosome of a cat does not carry information about color. Although the previous statements are correct, we must not forget that the Y chromosome actually contains a wealth of information about the possible color of a cat's fur. The locus on the X chromosome responsible for coat color only determines whether genes related to color will affect black or red.

If you are interested in the genetic basis for obtaining different colors, as well as what colors are theoretically possible, this article is for you.

Pigmentation
White color
Ticking and Tabby
Shaded
With white spots
FAQ
Explanations of the notations in the article

Cat colors come in a variety of patterns and colors. The names for these colors are often based on genetic theory. Many people are confused when faced with the names of colors that exist among cat lovers. This article will help to understand these terms and the reasons for their occurrence, but does not attempt to describe the mechanisms of inheritance and does not provide formulas for calculating the possible result of crossing different colors.

1. Pigmentation

The color of fur, skin and eyes depends on the presence of melanin in them. Melanin is found in the hair body in the form of microscopic granules that vary in shape, size and quantity, which causes differences in color.

There are two chemical varieties of melanin: eumelanin and phaeomelanin. Granules Eumelanin spherical and absorb almost all light, giving black pigmentation. Granules Phaeomelanin oblong (ellipsoidal in shape) and reflect light in the red-yellow-orange range.

Some genes can change the density of melanin granules in such a way that different colors are produced. The greatest differences are observed in dark (eumelanin-based) colors.

With a decrease in the number of eumelanin granules in the hair body black color changes through chocolate(or chestnut) to color cinnamon. Chocolate is recessive to black, and cinnamon is recessive to chocolate. Such mutations will be caused by the allele (B).

Mutations of dark group genes lead to the appearance blue, lilac and colors fawn. This is due to the grouping of pigment particles in the hair body. Cyan is a diluted black and represents different shades of grey. Lilac is a diluted chocolate color and is sometimes compared to the color of frost or lavender. Fawn (fawn) is a diluted cinnamon color - the color of café au lait or caramel. Such mutations depend on the location of the allele (D). Dilution is recessive relative to saturated shades.

Red-based (phaeomelanistic) colors have significantly less variation. Red the color is usually described as orange or marmalade, and in Russian - red. Some cats have such pale pigmentation that they can be called yellow. Cream- this is a diluted red, the color of cream. For the red gene, the symbol is used (O). Black color is recessive to red.

Red gene (O) linked to the X chromosome, so it is gender dependent. Cats have one X chromosome, so if a cat carries the red gene, it will be red. Cats have two X chromosomes, so a cat will be red if both X chromosomes carry the red gene. However, in many cats, the red gene is carried on only one chromosome, resulting in black pigmentation in the form of patches. This combination of red and black is called tortoiseshell(Tortoiseshell).

Typical Tortoiseshell color is randomly located spots of black and red. Some have more red, some have more black. Depending on the saturation, the spots can be either black-orange or blue-cream (these are usually not called tortoiseshell, but simply called - blue cream). Variations of black lead to the appearance chocolate tortoiseshells(Chocolate Tortie) and cinnamon tortoiseshells(Cinnamon Tortie), and their diluted versions are called lilac-cream tortoiseshell(Lilac-Cream Tortie) and Fawn-cream tortoiseshells(Fawn-Cream Tortie).

The described mutations have existed in Europe and the Western Hemisphere for hundreds of years. Another set of mutations was introduced from Asia, and is represented by Siamese and Burmese cats. Burmese bear the genes for color Sepia(Sepia) (cb), and Siamese - color spot genes Point(Pointed) (cs). Such mutations will be caused by the allele (WITH), their combination (cb/cs), like the Tonkin cat, represents the color mink(mink, mink).

Plain (C-)	Sepia (c b c b)	Mink (c b c s)	Point (c s c s)
Black (B-D-)	Sable Wax Sepia	Wax Mink Natural Mink	Seal-point
Blue (B-dd)	Blue Sepia	Blue Mink	Blue-point
Chocolate (bbD-)	Chocolate Sepia Champagne	Chocolate Mink Champagne Mink	Chocolate point
Lilac (bbdd)	Purple Sepia Platinum	Lilac Mink Platinum Mink	Lilac Point Platinum point
Cinnamon (b 1 b 1 D-)	Cinnamon Sepia	Cinnamon Mink Honey Mink	Cinnamon-point
Fawn (b 1 b 1 dd)	Fawn Sepia	Fawn Mink	Fawn-point
Red (D-O(O))	Red Sepia (Fawn Sepia)	Red Mink	Red point, red point (Flame-point)
Cream (ddO(O))	Cream Sepia (Fawn Sepia)	Cream Mink	Cream-point

Not shown in the table are two more colors of the albino mutation, which usually have a solid white coat, regardless of pigmentation genes. These are white with blue eyes (ca/ca), and white with pink eyes (c/c).

2. White cats

White color is the absence of any pigmentation. Solid white wool can be obtained in three completely different cases:

1. White albino.

This is a recessive variant, described in the previous section

2. Solid white spots

White spot factor (S) is not completely dominant, is subject to polygenetic modifications and usually results in the cat not being entirely white. However, the spots may be so dense that the animal appears completely white. White spots are described in the next section.

3. Dominant white

This mutation suppresses all other pigmentation genes, and results in white coat color and blue eyes. As the name suggests, this is the white dominant gene effect. (W).

In the dominant white, genes for other colors and patterns, although present, are completely hidden. The only way to determine the underlying genotype is by crossing with colored cats of a well-known genotype.

Crossing two dominant whites will usually result in all white kittens, but if both parents are heterozygous (w/w), then some kittens may show primary colors. If the genotype of the white parents is not known from the pedigree or test crosses, the mating result is unpredictable.

Dominant white is found in various breeds. Sometimes white Oriental Orientals are considered by some associations as a separate breed. The dominant white color has a much deeper blue eye color than albinos, and this is considered an advantage. The best blue eye color is observed in completely white Oriental Oriental cats that carry a suppressed chocolate gene.

Deafness in cats linked to spotting genes (S), and with a dominant white (W), but not with the albino gene ( c/c or ca/ca).

3. Ticking and Tubby

The previous paragraphs described solid colors. However, these colors are not the most common. Many cats are ticked, and most are ticked in a different color than the main one, a pattern called tabby.

Ticking is the result of gene expression agouti- denoted (A), leading to the appearance of stripes of light and dark pigmentation on each hair. The agouti gene allows full pigmentation for hair that has begun to grow, then slows down pigment synthesis for a while, and allows it again. When the hair reaches its full length and stops growing, pigment synthesis stops. As a result, the hair is densely colored at the tip, then there is a stripe of yellow or orange color, then again a densely pigmented area, descending to the yellow or orange root of the hair.

Agouti stripes are found in both eumelanistic and red base colors. In both cases, the band corresponds to a period of slowing melanin production. Agouti stripes in black-based colors are also caused by eumelanin (not phaeomelanin), but the pigment granules are sparse and arranged in islands, giving a yellow or orange tint. Thus, agouti is not a mixture of areas with eumelanin and phaeomelanin pigmentation.

In eumelanin-pigmented hairs, agouti stripes are usually yellowish shades. However, their color may be orange- this color is caused by a factor redhead colors. This polygenetic factor has not yet been isolated or identified, but breeders know how to select animals that produce warm tabby colors. In particular, brown tabby(Brown Tabby) is genetically black, but by selecting individuals with a strong red factor it was possible to obtain a rich brown color in the ticked hairs.

The mutation responsible for uniform color is called non-agouti(non-agouti) (a/a), and is recessive. The effect of non-agouti suppresses ticking so that the pigment is evenly distributed along the entire length of the hair, except at the root, where ticking is usually preserved to some extent.

Behind tabby gene answers (T), which causes stripes and spots of the primary color to appear on ticked wool. Commonly known types of tabbies are given the following descriptive names:

1. Tiger Tabby (Mackerel Tabby).

Ticked hair in stripes is located on the main color (like a tiger). This is the most common tabby pattern.

2. Classic Tabby.

The ticked hair is arranged in patches, often in the shape of bull's eyes on the sides, or butterflies on the back. This drawing is also called spotted tabby(Blotched Tabby).

3. Ticked Tabby.

Ticked hair is evenly distributed throughout the body, the coat looks as if freckled. This pattern is also called Agouti(Agouti Tabby) Abyssinian(Abyssinian Tabby) or wild.

4. Patched Tabby.

The ticked hair alternates with spots or rosettes of the primary color (as on a leopard or jaguar).

Agouti and tabby genes in combination with the basic colors produce the following patterns:

	Agouti(A-)			Non-agouti(aa)
	Ticket Ticked	brindle Mackerel	Classical Classic	Ticket Ticked	brindle Mackerel	Classical Classic
	(Tb)	(T-)	(T b T b)	(Tb)	(T-)	(T b T b)
Black (B-D-)	Brown ticked tabby	Brown brindle tabby	Brown classic tabby	Solid black Black Solid
Blue (B-dd)	Blue ticked tabby	Blue brindle tabby	Blue classic tabby	Solid blue Blue Solid
Chocolate (dd B-)	Chocolate ticked tabby	Chocolate brindle tabby	Chocolate classic tabby	Solid Chocolate Chocolate Solid
Lilac (bb dd)	Lilac ticked tabby	Lilac brindle tabby	Lilac classic tabby	Solid Chocolate Chocolate Solid
Cinnamon (b 1 b 1 D-)	Cinnamon ticked tabby	Cinnamon brindle tabby	Cinnamon classic tabby	Solid Cinnamon Cinnamon Solid
Fawn (b 1 b 1 dd)	Ticked tabby fawn	Tiger tabby fawn	Classic tabby fawn	Solid Fawn Fown Solid

Red (D-O(O))	Red ticked tabby	Red brindle tabby	Red classic tabby	Same as Agouti (A-) Non-agouti does not show up on orange pigment
Cream (ddO(O))	Cream ticked tabby	Cream brindle tabby	Cream classic tabby

Classic tabby (tb) recessive to brindle (T), brindle is recessive relative to the Abyssinian (Ta).

Agouti and tabby genes are also combined with all albino colors - sepia, mink and colorpoints. Americans recognize the Burmese and Tonka breeds only with the black-based non-agouti color (eumelanistic non-agouti) color, without recognizing tabby manifestations. The Singaporean (Singapura) recognizes only " sable agouti" (Sable Agouti Tabby) color - wax ticked tabby(seal sepia ticked tabby). Some associations allow tabby Siamese cats (Siamese) - their color is called tabby point(Tabby Point), or links point(Lynx Point) - with a lynx spot.

Note that there are no solid red or cream colors here. Although breeders produce uniformly colored red and cream cats by selecting for carriers of the red gene with a tendency to reduce the contrast of the pattern, the "M" on the forehead is still present in even the most uniform red-base (Phaeomelanistic) colors.

Ticked tabby in relation to Abyssinians and Somalis (Abyssinians, Somalis) is given special names:

Ruddy Abyssinian = Brown Ticked Tabby

Blue Abyssinian = Blue Ticked Tabby

Sorrel Abyssinian = Cinnamon Ticked Tabby

Fawn Abyssinian = Fawn Ticked Tabby

Sorrel Abyssinian is sometimes called red, But it's not right. All these colors are black-based. Red and Cream(Red, Cream) Somali and Abyssinian colors are not recognized by US associations.

Note that spotted tabby is not identified as a separate genotype. It is not entirely clear whether the spotted tabby is a mutation of the tabby gene, or whether it is simply the effect of polygenetic modifications of the mackerel tabby. Some breeders point to the existence of spotted tabby in various species of wild cats, as confirmation that the spotted tabby is an independent mutation. In practice, however, the spotted tabby produces offspring with patterns ranging from spotted to brindle, and breeders must continually select sires with clear markings, otherwise the pattern of the offspring will shift to brindle.

Tortoiseshell cats can also have a tabby pattern. IN tortoiseshell tabby(torbie), the tabby pattern appears on both red and black areas. Solid and ticked stripes on red areas continue without interruption to black areas.

4. Shaded

In a regular tabby, the ticked hairs have light stripes, but they are not devoid of color. Typically, the light stripes are yellowish in color, but can sometimes appear orange.

Less commonly, agouti stripes add a tint to the main color. Shaded(Shading) expands the agouti stripes so that the light areas can reach the root of the hair. This effect results in the hair having a colored tip, the color of which is determined by the base color gene, and the hair itself is much lighter. If a light area of hair with white tones is Silver(Silver), if yellow or cream - golden(Golden).

There have been several explanations for the genetics of shaded colors. Previously it was believed that the gene chinchillas (Ch)(Chinchilla) is a modification of the albino gene. If this were the case, then colors such as shaded sepia, mink and colorpoint would not be possible. Breeder experiments refute this theory. It was later thought that a separate gene, called the inhibitor(I). But this theory could not explain all the varieties of shaded colors and the success of breeders in obtaining them. Therefore, it is now believed that at least two genes cause shading, however, this theory has not yet been proven experimentally.

All of these theories try to explain hereditary factors that suppress pigment synthesis after hair reaches a certain length. The combination of shading with agouti and tabby leads to the appearance of colors such as chinchilla(Chinchilla) Shaded silver(Shaded Silver) Silver tabby(Silver Tabby) and Smoke(Smoke).

U chinchillas(Chinchilla) each hair is well colored at the end and pale to the root, so all the hair appears lightly colored and there is no tabby pattern effect. The tipping is so weak that the color even seems white at first glance, but upon closer inspection it seems to sparkle.

IN Shaded Silver(Shaded Silver), all hair is colored where the agouti stripe usually begins. Like the Chinchilla, the ticked and solid areas are pale colored where agouti stripes would normally be, so the pattern is not noticeable. However, in Shaded Silver the colored tips are long enough so that the underlying color is clearly visible, especially on the head and back.

U Silver Tabby(Silver Tabby) Ticked hair is brightly colored at the ends and pale to the root, but solid hair has normal color saturation. The tabby pattern is enhanced by the contrast between the almost white ticked coat and the areas of base color.

Smoky(Smoke) pattern is the result of shading a solid non-agouti color. All hairs are well colored to the point where an agouti stripe would appear and then fade into an almost white undercoat. This color looks like the main color, but if you blow on the coat, a contrasting and white undercoat is noticeable. It is also clearly visible when the animal moves.

The same shaded patterns can be found on the golden undercoat. They are called Golden Chinchilla(Golden Chinchilla) Shaded Golden(Shaded Golden) Golden Tabby(Golden Tabby) and Golden Smoky(Golden Smoke). Unlike white (silver) shaded animals, these animals have an undercoat of warm cream or apricot color.

The eumelanistic shaded colors are the most impressive as they have more contrast, but the red and cream colors are also very beautiful. Red-based shaded colors are often called "Cameo", their correspondence to the usual names is given below:

Shell Cameo = Red Chinchilla

Shaded Cameo = Red Shaded Silver

Cameo Tabby = Red Shaded Silver

Smoke Cameo = Red Smoke

Since shading is combined with both black-base and red-base colors, it can appear in all tortoiseshell colors.

Theoretically, golden undercoat can also be obtained in a red-base color, but so far breeders have not found such a combination worthy of attention. Lack of contrast in Red Golden Shaded makes the effect almost indistinguishable, but in black spots Tortoiseshell Golden Shaded or Tortoiseshell Golden Chinchilla it is quite noticeable.

5. With white spots

A very common mutation that results in white spots. The spotted color is sometimes called "piebald". There are a lot of varieties of stains - from white slippers, white feet, to white nose or chin. From small white areas to almost complete absence of areas with the main color.

White spots can be considered a mask on the main color. Usually, the owners of cats whose dark stripes are preserved only on the head and tail consider their pets white. This is not correct - in fact, these are cats with a tabby pattern that is hidden under the white spots.

White spots are found in any color and in any of the patterns described above. It is generally accepted to name such colors by indicating the main color and adding " with white". For example, Red brindle tabby(Red Mackerel Tabby) with white spots is called Red brindle tabby with white(Red Mackerel Tabby and White), and Lilac becomes Lilac with white.

Tortoiseshell with white(Tortoiseshell and White) has a special name - Calico(Calico, Chintz). Hence, Blue cream with white sometimes called Diluted Calico(Dilute calico).

White spot factor (S)- dominant mutation. Homozygous cats (S/S) usually have a larger white area than heterozygotes (S/s), but other genes can change the extent of white spots. Sometimes white spots can increase with age (!).

The white spot factor can result in blue-eyed cats and cats with mixed eyes if the spot covers one eye. This gene is associated with deafness, especially if the white patches reach the ears. If the white patch covers the eyes and ears, then it is possible that the result will be a deaf cat with blue eyes. Deafness can affect one or both ears. This is caused by degeneration of the concha of the inner ear, which begins in the first days of life. Such deafness is incurable.

It has been observed that a white spot may be present on a cat white color! Of course, a spot on white is visually indistinguishable.

6. Frequently asked questions

Is it true that there are no tortoiseshell cats?

Tortoiseshell, blue-cream, patched tabby, calico, etc. colors are gender dependent. Therefore, they appear only in cats. It is extremely rare that they can appear in cats, but this is a genetic disorder. These cats have XXY instead of the normal XY chromosome combination and are usually infertile.

Why do all red cats have a tabby pattern?

This is the result of the manifestation of the agouti gene. The agouti gene regulates the presence of stripes of different colors on the hairs of the coat. The recessive non-agouti gene suppresses tabby and leads to uniform hair color along the entire length. This non-agouti gene does not affect the red pigment, so the tabby is always visible. Even a cat that is solid in non-red areas has tabbies in the red areas.

Is it true that there are only 3 main cat coat colors?

Yes its true. It is black, red and white. These colors appear to varying degrees under the influence of attenuating genes. Black fades into blue (various shades of gray, including silver) and chocolate (lilac and light brown). Light brown lightens to yellow-brown (fawn) and red to cream.

My cat is not a Siamese, why then does she have a Siamese color?

The Siamese spot (mask) gene comes from cats from Asia. These cats have been crossed with other breeds and the gene is now widespread and present in many non-Siamese cats. This gene is temperature sensitive and causes darkening of the extremities (ears, tail, muzzle) that are more sensitive to cold. Kittens are born completely white. If they live in cool conditions, their coat will darken as they age, while kittens raised in warm conditions will have a light coat, and sometimes only a small spot on the nose will darken. What's very interesting is that if you bandage a cat's leg, the new fur that grows under the bandage, where it's warmer, will be lighter than in the exposed areas. This is immediately unnoticeable, because old dark hair does not change color. As the cat sheds, the white patch will gradually appear. Spot areas will also lighten if your cat has been sick for a long time with a fever.

Why did two short-haired cats give birth to a long-haired kitten?

Recessive genes, in addition to the genes for calico color and true white coat color in cats with blue eyes, are also genes for long hair. They are spun, on average, every third generation. Therefore, if a long-haired cat is born with two short-haired cats, then that kitten's grandparents were long-haired.

What color can cats' eyes be?

Eye color is always genetically linked to color.

Colorpoint cats have blue eyes.

White cats and cats with white dominance may have:

Blue eyes - green, yellow, light brown - multi-colored (one blue and the other yellow or green).

Other cats may have yellow, green, but not blue eyes. Most cats have greenish-yellow to gold eyes. Colors such as “deep green” or “rich copper” are found in purebred cats that have been specially bred for this eye shade, but can sometimes appear in regular cats as well.

Are all white cats deaf?

The dominant white gene carries hereditary characteristics that weaken the structure of the inner ear in true white cats with blue eyes. In cats with different colored eyes, the ear on the side of the blue eye cannot hear. True white cats do not have a yellowish tint, they have pink skin and pink paw pads, and blue eyes without rims or spots of a different color. White color can also be caused by a recessive albino gene, which does not cause deafness.

7. Explanations of notations in the article

The article uses designations generally accepted in genetics, which, however, are not necessary to understand the essence of the matter. Typically, genes for different characteristics are designated by letters, usually the first letter of the gene name. Mutations of a gene are called allomorphs, or more commonly, alleles. Dominant alleles are indicated in capital letters, recessive alleles are indicated in lowercase letters.

Typically in genetics, multiple alleles are distinguished by superscript letters. For example, Black - (B), Brown - (b), and Light Brown is designated as b l. The article did not use superscript characters, so it turns out (bl).

Every cat has a pair of genes for each trait, one from each parent. A purebred black cat is designated as (B/B), and a chocolate (chocolate (brown)) cat is designated as (b/b). These are called homozygous, since they received the same set of genes from both parents. A black cat with a recessive gene for chocolate color is designated as (B/b) - its parents have different genes.

Cats with recessive traits (like (B/b)) are called heterozygotes. They are indistinguishable from homozygous individuals; differences appear only in the offspring. If the presence of a dominant gene determines a visible trait, the paper used a form like (B/-), where the minus indicates that the second gene is unknown or not important for the visible trait.

Cat to human age ratio

Table of probable colors of kittens

Loci responsible for color.

Where do tortoiseshell cats come from?

Red cats in breeding programs.

Use of red studs in breeding programs for Chocolate and Lilac cats.

Now a little about everyone.

Genetics of red and black.

Agouti and non-agouti

Red series colors

Silver and gold

ELEMENTARY RULES OF GENETICS OF CAT COLOR:

Dominant and recessive colors

Formation of color

Loci responsible for color.

Where do tortoiseshell cats come from?

White color

Van color

Bicolor or color with white

Burmese color

1. Pigmentation

1. White albino.

2. Solid white spots

3. Dominant white

3. Ticking and Tubby

1. Tiger Tabby (Mackerel Tabby).

2. Classic Tabby.

3. Ticked Tabby.

4. Patched Tabby.

4. Shaded

5. With white spots

6. Frequently asked questions

***Bicolor or* color *with white***

***Burmese* *color***