Cats of a Different Color

by R. Roger Breton and Nancy J. Creek

LINKS:
  Feline Genetics Primer & free genetics software
  Canine Genetics Primer & free genetics software
  FSpeed
  Breeders Assistant Pedigree Software
  DMOZ Cat Genetics Resources
  Other Resources

This in-depth article is reproduced with kind permission of R. Roger Breton.


Our word 'tabby', used to indicate a cat with stripes or irregular patterns, comes from the Spanish tabi - a kind of cloth with irregular tie-die-like markings.

Contents

 1. Cells, Chromosomes, and Genes
 2. Mitosis and Mendel
 3. Meiosis
 4. Male, Female, and Maybe
 5. Mutations
 6. The Mapped-out Genes
 6.1 The Body-Conformation Genes
 6.2 The Coat-Conformation Genes
 6.3 The Color-Conformation Genes
   6.3.1 The Color Gene
   6.3.2 The Color-Density Gene
   6.3.3 The Orange-Making Gene
   6.3.4 The Eight Cat Colors
 6.4 The Albinism Gene
 6.5 The Agouti Gene
 6.6 The Tabby Genes
 6.7 The Color-Inhibitor Gene
 6.8 The Spotting Gene
 6.9 The Dominant-White Gene
 6.10 Polygenes
 7. The Eye Colors
 8. Naming the Colors
 9. The Standard Colors
 9.1 The Standard Solid Colors
 9.2 The Standard Patch Colors
 9.3 The Standard Tortoiseshell Colors
 9.4 The Standard Calico Colors
 9.5 The Standard Tabby Colors
 9.6 The Standard Tabby-Patch Colors
 9.7 The Standard Tabby-Tortoiseshell Colors
 9.8 The Standard Tabby-Calico Colors
 10. The Specific Tabby Colors
 10.1 The Bronze Tabby Colors
 10.2 The Silver Tabby Colors
 10.3 The Abyssinian Colors
 10.4 The Silver Abyssinian Colors
 11. The Shaded Colors
 11.1 The Smoke Colors
 11.2 The Shade Colors
 11.3 The Chinchilla Colors
 11.4 The Tortoiseshell Chinchilla Colors
 11.5 The Golden Chinchilla Colors
 11.6 The Golden Tortoiseshell Chinchilla Colors
 12. The Oriental Colors
 12.1 The Oriental Solid Colors
 12.2 The Burmese Colors
 12.3 The Tonkinese Colors
 12.4 The Siamese Colors
 12.5 The Tortoiseshell-Point Siamese Colors
 12.6 The Lynx-Point Siamese Colors
 12.7 The Tabby-Tortoiseshell-Point Siamese Colors
 13. The White Colors
 13.1 The Van Colors
 13.2 The Full-Inhibited While Color
 13.3 The Full-Spotted White Color
 13.4 The Dominant White Color
 13.5 The Blue-Eyed Albino White Color
 13.6 The Albino White Color


1. Cells, Chromosomes, and Genes

From a 35-pound Main Coon to a 5-pound Devon Rex; from the small folded caps of a Scottish Fold to the great, delicate ears of a Balinese; from the 4-inch coat of a Chinchilla Persian to the fuzzy down of a Sphinx; from the deep Ebony of a Bombay to the translucent white of a Turkish Angora; from the solid color of a Havana Brown to the rich tabbiness of a Norwegian Forest Cat: the variety and beauty to be found in the domestic cat are beyond measure. When these characteristics are coupled with the genetically patterned and environmentally tailored personalities of the individuals, it can be seen that each animal is as unique as it is possible to be. There truly is a cat for everyone.

Wide as the range of cats is, it pales when compared with the varieties of 'the Other Pet'. Why should the dog exhibit such a wide spectrum of body types, looking like completely different creatures in some cases, while cats always look like cats (as horses always look like horses)? The secrets behind the wide variations in possible cats, and why cats, unlike dogs, resist gross changes and always look like cats, can be found in its genetic makeup.

In order to understand what happens genetically when two cats do their thing, it is necessary to understand a few basic things about genetics in general. To study genetics, is to study evolution in miniature, for it is through the mechanism of genetics that evolution makes itself felt. In 'The Making of the Cat', our article on feline evolution, we showed how the gross evolution of the cat came about, and how this gross mechanism was applied to the European Wildcat to evolve the African Wildcat, the immediate forerunner of our cats. We will examine this mechanism itself to better understand how the first domestic cat has become the dozens of breeds available today, and how cat breeders use this mechanism to create new breeds or improve existing ones.

Cats, like people, are multi-cellular creatures: that is, their bodies are composed of cells, lots and lots of cells. Unlike primitive multicellular creatures, cat bodies are not mere colonies of cells, but rather societies of cells, with each type of cell doing a specific task. To one specific type of cells, the germ cells (ova in females and sperm in males), fall the task of passing the genetic code to the next generation. The method the Great Engineer has developed to carry this out is one of the most awesome, most elegant, and most beautiful processes in nature.

The cells of a cat, with few special exceptions, are eukaryotic, that is, they have a membrane surrounding them (acting as a sort of skin), are composed of cytoplasm (cell stuff) containing specialized organelles (the parts that do the cell's task), and have an inner membrane surrounding a nucleus. It is this nucleus that contains all the genetic materials.

Within the nucleus of a cell are found the chromosomes, long irregular threads of genetic material. These chromosomes are arranged in pairs: 19 pairs in a cat, 23 pairs in a human. It is these 38 chromosomes that contain the 'blueprint' for the individual cat.

When inspected under a microscope, the chromosomes reveal irregular light and dark bands: hundreds of thousands, perhaps millions per chromosome. These light and dark bands are the genes, the actual genetic codes. Each gene controls a single feature or group of features in the makeup of the individual. Many genes interact: a single feature may be controlled by one, two, or a dozen genes. This makes the mapping of the genes difficult, and only a few major genes have been mapped out for the cat.

The chromosome is itself composed primarily of the macromolecule DNA, (deoxyribonucleic acid): one single molecule running the entire length of the chromosome. DNA is a double helix, as two springs wound within each other. Each helix is composed of a long chain of alternating phosphate and deoxyribose units, connected helix to helix by ladder-like rungs of four differing purine and pyridamine compounds.

It is not the number of differing compounds that provide the secret of DNA's success, but rather the number of rungs in the ladder (uncounted millions) and the order of the amino acids that make up the rungs. The four different amino acids are arranged in groups of three, forming a 64-letter alphabet. This alphabet is used to compose words of varying length, each of which is a gene (one particular letter is always used to indicate the start of a gene). Each gene controls the development of a specific characteristic of the lifeform. There is an all-but-infinite number of possible genes. As a result, the DNA of a lifeform contains its blueprint, no two alike, and the variety and numbers of possible lifeforms have even today barely begun.

2. Mitosis and Mendel

When a cell has absorbed enough of the various amino acids and other compounds necessary, it makes another cell by dividing. This process is called mitosis, and is fundamental to life.

Not too long ago, it was thought that the chromosomes were generated immediately prior to mitosis, and dissolved away afterwards. This turned out not to be true. The extremely tiny chromosomes, normally invisible in an optical microscope, shorten and thicken during mitosis, becoming visible temporarily.

The rather complex process of mitosis can perhaps be explained simply in a step-by-step manner:

  1. The cell senses sufficient growth and nutrients to support two cells.
  2. The invisible chromosomes duplicate themselves through the wonder of DNA replication. Various enzymes are used as keys to unlock and unwind the double helix into two single helices. Each of these helices then uses other enzymes to lock the proper parts (the amino acids and other stuff) together to build a new second helix, complete with all transverse rungs, so that the results will be exact replicas of the original double helix. This winding and unwinding of the DNA can take place at speeds up to 1800 rpm! The two daughter chromosomes remain joined at a single point, called the centromere.
  3. The chromosomes wind themselves up, shortening and thickening, making them visible under the microscope, and attach themselves to the nuclear membrane.
  4. The nuclear membrane dissolves into a fibrous spindle, with at least one fiber passing through each centromere (there are many more fibers than centromeres).
  5. The fibers stretch and pull the centromeres apart, moving the chromosomes to opposite sides of the cell.
  6. The spindles dissolve into two new nuclear membranes, one around each group of chromosomes.
  7. The cell divides into two daughter cells.
  8. The chromosomes of each daughter cell unwind back into invisibility and mitosis is complete. Genetically, each daughter cell is an exact duplicate of the parent cell.

Since the genetic coding is carried in the rungs of the DNA and only consists of four different materials arranged in groups of three to form words of varying length written with a 64-letter alphabet, the instructions for a 'cat' may be considered to consist of two sets of 19 'books,' each millions of words long, one set from each of the cat's parents. The numbers of possible instructions are more than astronomical: there are far more possible instructions in one single chromosome than there are atoms in the known universe!

A single gene is a group of instructions of some indeterminate length. Somewhere among all the other codes is a set of instructions composing the 'white' gene, and what that set says will determine if the cat is white or non-white.

Since a cat receives two sets of instructions, one from each parent, what happens when one parent says 'make the fur white' and the other says 'make the fur non-white'? Will they effect a compromise and make the fur pastel? No, they will not. Each and every single gene has at least two levels of expression (many have more), called alleles, which will determine the overall effect. In the case given, the 'make the fur white' allele, W, is dominant, while the 'make the fur non-white' allele, w, is recessive. As a result, the fur may be white or non-white, not pastel (we're only speaking of the 'white' gene here, a gray cat is caused by an entirely different gene).

 

_W _w
W_ WW Ww
w_ wW ww

Single-Cell Mendelian Pattern

In order to understand how this works, lets run through a couple of simple examples using the white gene. A cat has two and only two white genes. Since each white gene, for the purposes of our examples, consists of one of two alleles, W or w, a cat may have one of four possible karyotypes (genetic codes) for white: WW, Ww, wW, ww. Since W is dominant to w, the codes WW, Ww, and wW produce white cats, while the code ww produces a non-white cat.

The double-dominant WW white cat has only white alleles in its white genes. It is classed as homozygous (same-celled) for white, and will produce only white offspring, regardless of the karyotype of its mate.

The single-dominant Ww or wW white cat has one of each allele in its white genes. It is classed as heterozygous (different-celled) for white, and may or may not produce white offspring, depending upon the karyotype of its mate.

The recessive ww non-white cat has only non-white alleles in its white genes. It is classed as homozygous for non-white, and may or may not produce white offspring, depending upon the karyotype of its mate.

Assuming these cats mate, there are sixteen different possible karyotype combinations. Since each cat in these sixteen combinations will pass on to their offspring one and only one allele, there are four possible genetic combinations from each mating. There are sixty-four possible combinations of offspring.

Inspecting these possible offspring, several patterns emerge. Of the 64 possible offspring, 16, or exactly one-quarter, have any given pattern. This means that one quarter of all possible matings will be homozygous for white, WW, two quarters will be heterozygous for white, Ww or wW (which are really the same thing), and one quarter will be homozygous for non-white, ww.

Since homozygous white and heterozygous white will both produce white cats, three-quarters of all possible combinations will produce white cats, and only one-quarter will produce non-white cats. This 3:1 ratio is known as the Mendelian ratio, after Gregor Johann Mendel, the father of the science of genetics.

 

WW Ww wW ww
_W _W _W _w _w _W _w _w
WW W_ WW WW WW Ww Ww WW Ww Ww
W_ WW WW WW Ww Ww WW Ww Ww
Ww W_ WW WW WW Ww Ww WW Ww Ww
w_ WW wW wW ww ww wW ww ww
wW w_ WW wW wW ww ww wW ww ww
W_ WW WW WW Ww Ww WW Ww Ww
ww w_ WW wW wW ww ww wW ww ww
w_ WW wW wW ww ww wW ww ww

Two-Cell Mendelian Pattern

Further inspection leads us to several conclusions. If a homozygous white cat mates, all offspring will be white. If two homozygous white cats mate, all offspring will be homozygous white. If a homozygous white cat mates with a heterozygous white cat, there will be both homozygous white and heterozygous white offspring in a 1:1 ratio. If a homozygous white cat mates with a homozygous non-white cat, all offspring will be heterozygous white. Thus, a homozygous white cat can only produce white offspring, regardless of the karyotype of its mate, and is said to be true breeding for white.

If two heterozygous white cats mate, there will be homozygous white, heterozygous white, and homozygous non-white offspring in a ratio of 1:2:1. The ratio of white to non-white offspring is the Mendelian ration of 3:1. If a heterozygous white cat mates with a homozygous non-white cat, there will be both heterozygous white and homozygous non-white offspring in a 1:1 ratio.

If two homozygous non-white cats mate, all offspring will be homozygous non-white. Homozygous non-white cats are therefore true-breeding for non-white when co-bred.

Geneticists differentiate between what a cat is genetically versus what it looks like by defining its genotype versus its phenotype. A homozygous white cat has a white genotype and a white phenotype. Likewise, a homozygous non-white cat has a non-white genotype and a non-white phenotype. A heterozygous white cat, on the other hand, has both a white genotype and a non-white genotype, but only a white phenotype.

Naturally, in a given litter of four kittens the chances of having a true Mendelian ratio are slim (slightly better than 1:11), so several generations of pure white kittens could be bred, still carrying a recessive non-white allele. In all good faith you then breed your several-generations-all-white-but-heterozygous female to a similar several-generation-all-white-but heterozygous male and Voila! A black kitten! The non-white genotype has finally shown itself.

This Mendelian patterning is the basic rule of genetics. Since the rule is so simple, why is it so hard to predict things genetically? The reason is that we are dealing with more than one gene from each parent. The number of possible offspring combinations is two to the power of the number of genes: one gene from each parent is two genes, two squared is four possibilities; two from each parent is four, two to the fourth is sixteen; three from each is six, two to the sixth is 64; ... There are literally hundreds of millions of genes for one cat, yet a mere hundred from each parent produces a 61-digit number for the possible offspring combinations!

3. Meiosis

Since each cell contains the entire chromosome set, 19 pairs, how is it possible for a parent to pass on only the genes from one chromosome of a pair, and not both. This is accomplished via the gametes: the germ cells, ova for females and sperm for males. Within the gonads (ovaries or testes), these special cells go through a division process known as meiosis.

Unlike the normal process of mitosis, where the chromosomes are faithfully replicated into duplicates of themselves, in meiosis the resultant gametes have only half the number of chromosomes, one from each original pair. This involves a double division.

As in mitosis, meiosis begins when the cell senses sufficient growth and nutrients to support division. The invisible chromosomes are duplicated through DNA replication. As usual, the two daughter chromosomes remain joined at the centromere. The chromosomes wind themselves up, shortening and thickening, becoming visible under the microscope. Each new chromosome twin aligns itself with its homologous counterpart: the twin chromosome from its opposite number in the original chromosome pair. The two twin chromosomes intertwine into a tetrad and exchange genes in a not clearly understood process that randomizes the genes between the twins. The tetrad attaches itself to the nuclear membrane. The nuclear membrane dissolves into a spindle, with at least one fiber passing through both centromeres of each tetrad. The fibers stretch and pull the tetrads apart, pulling the chromosome twins to opposite sides of the cell. Once the chromosome twins are at the poles of the spindle, the spindle dissolves and reforms as two separate parallel spindles at right angles to the original spindle, with at least one fiber through each centromere. At this time there are effectively two mitoses taking place. The parallel spindles pull the centromeres apart, forming four separate groups of chromosomes, each of which consists of one-half the normal number. The spindles dissolve and four new nuclear membranes form, one around each group of chromosomes. The chromosomes unwind back into invisibility, the cell divides into four gametes, each having 19 chromosomes, and meiosis is complete.

At the moment of conception, a single sperm penetrates a single ovum. The ovum absorbs the sperm, merging the sperm's nucleus with its own and pairing the two sets of chromosomes. The ovum has now become a zygote, which begins dividing through the normal mitosis process, and a kitten is on its way.

4. Male, Female, and Maybe

The 19 pairs of chromosomes in a cat carry the numbers 1 through 18, plus X and Y. The X and Y chromosomes are very special, for they determine the sex of the kitten. A female cat has two X chromosomes, XX, while a male cat has one X and one Y chromosome, XY, so if we follow the Mendelian pattern for sex determination we find that the female parent can provide only an X chromosome to her offspring, while the male parent can provide either an X chromosome or a Y chromosome. The resulting kittens are either XX or XY, as determined by the father. The same rule also applies to people (Sorry guys, if you and the wife have seven girls, it's your fault, not hers!).

Since the sex chromosomes follow the same rules as the other chromosomes, why bother mentioning them separately? Because they don't exactly follow the same rules: the X chromosome is longer than the Y chromosome, and it is this extra length that carries the codes for the female. When there is only one set of these extra codes, they act as recessives, allowing the male characteristic to dominate. When there are two sets, they act as dominants, and suppress the male characteristics. Thus, female and male kittens.

We could end the argument here if it weren't for two complications. First, the extra-length of the X chromosome carries some genes that are for other than sex characteristics (such as the gene for orange fur): such characteristics are said to be sex-linked, and operate differently in males and females.

A further complication comes with incomplete separation of the X gene twin at the centromere.

An X-X gene twin has its centromere exactly where Ys would become Xs. If an X were to fracture at the centromere during the process of separation, it would become an effective Y. This is rare but by no means unheard of, and produces a 'false' Y (shown as y to differentiate it) from a female XX parent.

Another variation is incomplete separation, where only a 'false centromere' is separated from the gene twin, with or without a part of the twin, causing one gamete to have 18 chromosomes (neither an X or a y while the other has 20 (either two Xs, an Xy, or two ys, depending on the point and angle of fracture).

These variations on the sex chromosomes mean that a female, being XX in nature, can produce ova with the following: XX, Xy, yy, X, y, or - (no sex chromosome). A male, being XY, can produce sperm with XY, Yy, X, Y, y, or -. A zygote, taking one gamete from each parent, may then be any of 36 possibilities.

 

XX
XX Xy yy X y -
XY XY XXXY XXYy XYyy XXY XYy XY-
Yy XXYy XYyy Yyyy XYy Yyy Yy-
X XXX XXy Xyy XX Xy X-
Y XXY XYy Yyy XY Yy Y-
y XXy Xyy yyy Xy Yy y-
- XX- Xy- yy- X- y- --

X and Y Chromosome Variations

Since at least one X is required (can't build a puzzle without all the pieces), we may immediately ignore Yyyy, Yyy, yyy, Yy-, yy-, Yy, yy, Y-, y-, and --.

In a like manner, XXXY, XXYy, and XYyy have too many pieces and are unstable, usually dying at conception, in the womb, or soon after birth (and invariably before puberty) from gross birth defects due to over-emphasis of various sex-linked traits.

Turner females, X-, show all normal female characteristics save that they have difficulty reproducing due to the absence of a paired sex chromosome, which inhibits normal meiosis.

Kleinfelter superfemales, XXX, tend to exhibit an unusually strong maternal instinct, often refusing to wean or surrender their young. This leads to psychological damage in the young, usually resulting in antisocial behavior.

Kleinfelter supermales, XYy or Xyy, tend to exhibit a generally antisocial behavior, often leading to unnecessary fighting to the point of inhibiting mating. As an interesting aside, among us humans approximately 5 per cent of convicted male felons are supermales. This is far above the percentage of Kleinfelter supermales in the overall population.

Hermaphrodites, XXy and XXY, have male bodies but tend to exhibit various female characteristics, often adopting orphan kittens or other young. One such cat adopted a litter of mice, which it lovingly raised while gleefully hunting their relatives. Hermaphrodites are almost invariably sterile, sometime having both sets of sexual organs with neither fully developed. This is the most common of the aberrant sexual makeups.

Pseudoparthenogenetic females, XX-, or males, XY-, are identical to normal cats in every way save that their sex and sex-linked characteristics come only from one parent.

Gene-reversal males, Xy, suffer partial gene reversal, receiving a normal X from one parent and a y from the other parent's X. This is the rarest of the aberrant sexual makeups.

Pseudoparthenogenetic and gene-reversal animals often suffer from birth defects and other signs of the aberrant genetic construct.

Normal females, XX, and males, XY, are by definition the norm and vastly outnumber all other type combined. Chances are less than 1:10,000 that any given cat has a genetically aberrant sexual makeup, the most common of which is hermaphroditism, about 1:11,000.

5. Mutations

Going back to genes in general, those genes that are found in the African Wildcat, felis lybica, the immediate ancestor of our cats, are termed 'wild.' These genes may be considered to be the basic stock of all cats.

Since all cats do not look like African Wildcats (brown tabbies), it is obvious that some changes have taken place in the genetic codes. These changes occur all the time, and are called mutations. Unlike the distortions shown in cheap post-apocalypse or ecological-disaster movies, mutations rarely occur at the gross level, but rather at the level of the genetic codes themselves.

Mutations occur when, in the course of mitosis or meiosis, there is an imperfect replication or joining of the components of the DNA macromolecule. Such imperfections can occur as a result of a chemical imbalance within the body that affects replication. Most commonly these days such an imbalance is caused by the introduction of some foreign agent into the body (such as nicotine or, for an extreme example, thalidomide) which acts as a catalyst and affects the keying action of the enzymes during replication. Such agents are called mutagens.

The greatest of all mutagens is radiation. It is believed that the vast majority of spontaneous mutations, such as extra toes, long hair, albinism, etc., that keep reoccurring in an otherwise clean gene pool are caused by solar radiation, cosmic rays, the Earth's own background radiation, and most probably, by radioactive isotopes of the atoms making up DNA itself, most significantly carbon-14. (One of the dangers of nuclear war, other than the obvious, is that the increase in background radiation and atmospheric carbon-14 may increase the numbers of spontaneous mutations to the point where the germ cells lose viability, and whole species, even genera, would go the way of the dinosaur.)

Mutations are the very essence of evolution (or of a breeding program, which is merely evolution guided by man). It is through mutation that the survival of the fittest takes place.

To illustrate this, let's assume a species of striped cat living on the plains. He undergoes a mutation creating a spotted coat (the stripes are broken up). For our plains friend, the spots don't blend as well as stripes with the long shadows and colors of the grasses, his prey can see and avoid him better, and he soon evolves out. This was a detrimental mutation (most are).

Now let's assume the same species of striped cat living in woodlands. He undergoes the same mutation creating a spotted coat. In his case, the spots blend better with the dapple of light and shadow playing through the trees, his prey can't see or avoid him as well, and spots are soon the 'in' thing. This was a beneficial mutation. From the same parent stock we soon have two differing sub-species, one striped, living on the plains, and one spotted, living in the woods.

In a domestic situation, a litter is born to two normal cats, wherein one of the kittens is hairless. Thinking the hairlessness is different enough to be a desired feature, especially for those with allergies, the kitten is very carefully bred to other cats, back and forth over several generations, until the hairlessness breeds true. Thus the Sphinx, a hairless domestic cat and the ultimate in hypo-allergenic cats, was developed.

6. The Mapped-out Genes

As stated earlier, a few of the common cat genes have been identified and mapped. These genes are grouped according to the effects they have: the body-conformation genes that affect the shape of the body or body parts; the coat-conformation genes that affect the texture and length of the coat; and the color-conformation genes that affect the color and pattern of the coat.

The color-conformations genes are themselves divided into three groups: the color genes which control the color of the coat and its density; the color-pattern genes which control the pattern of the coat and expression of the color; and the color-masking genes which control the degree and type of masking of the basic color.

6.1 The Body-Conformation Genes

The body-conformation genes affect the basic conformation of the parts of the body: ears, tail and feet. There are literally thousands of body conformation genes, but only a few have been mapped: normal or Scottish fold ears, normal or Japanese bobtail, normal or Manx taillessness and spinal curve, and normal or polydactyl feet.

6.2 The Coat-Conformation Genes

The coat conformation genes affect such things as the length and texture of the coat.

Note that there are three different Rex mutations producing almost identical effects. There are still three different genes involved, however.

6.3 The Color-Conformation Genes

The color-conformation genes determine the color, pattern, and expression of the coat. Since these characteristics are among the most important of the cat's features, at least from a breeding point of view, more emphasis is given the color conformation genes than the others.

These genes fall into three logical groups: those that control the color, those that control the pattern, and those that control the color expression. Each of these groups contains several differing but interrelated genes.

6.3.1 The Color Gene

The first of the genes controlling coat color is the color gene. This gene controls the actual color of the coat and comes in three alleles: black, dark brown, or light brown. This three-level dominance is not at all uncommon: the albinism gene, for example, has five levels.

The black allele, B, is wild, is dominant, and produces a black or black-and-brown tabby coat, depending upon the presence of the agouti gene. Technically, the black is an almost-black, super-dark brown that is virtually black; true black is theoretically impossible, but often reached in the practical sense (so much for theory).

The dark-brown allele, b, is mutant, is recessive to black but dominant to light brown, and reduces black to dark brown.

The light-brown allele, bl, is mutant, is recessive to both black and dark brown, and reduces black to a medium brown.

6.3.2 The Color-Density Gene

The second of the genes controlling the coat color is the color-density gene. This gene controls the uniformity of distribution of pigment throughout the hair and comes in two alleles: dense, D, and dilute, d.

The dense allele, D, is wild, is dominant, and causes pigment to be distributed evenly throughout each hair, making the color deep and pure. A dense coat will be black, dark brown, medium brown, or orange.

The dilute allele, d, is mutant, is recessive, and causes pigment to be agglutinated into microscopic clumps surrounded by translucent unpigmented areas, allowing white light to shine through and diluting the color. A dilute coat will be blue (gray), tan, beige, or cream.

6.3.3 The Orange-Making Gene

The second of the genes controlling coat color is the orange-making gene. This gene controls the conversion of the coat color into orange and the masking of the agouti gene and comes in two alleles: non-orange and orange.

The non-orange allele, o, is wild and allows full expression of the black or brown colors. The orange allele, O, is mutant and converts black or brown to orange and masks the effects of the non-agouti mutation of the agouti gene (all orange cats are tabbies).

This gene is sex-linked; it is carried on the X chromosome beyond the limit of the Y chromosome. Therefore, in males there is no homologous pairing, and the single orange-making gene stands alone. As a result there is no dominance effect in males: they are either orange or non-orange. If a male possesses the non-orange allele, o, all colors (black, dark brown, or light brown) will be expressed. If he possesses the orange allele, O, all colors will be converted to orange.

In females there is a homologous pairing, one gene being carried on each of the two X chromosomes. These two genes act together in a very special manner (as a sort of tri-state gene), and again there is no dominance effect.

If the female is homozygous for non-orange, oo, all colors will be expressed. If she is homozygous for orange, OO, all colors will be converted to orange. It is when she is heterozygous for orange, Oo, that interesting things begin to happen: through a very elegant process, the black-and-orange tortoiseshell or brindled female is possible.

Shortly after conception, when a female zygote is only some dozens of cells in size, a chemical trigger is activated to start the process of generating a female kitten. This same trigger also causes the zygote to 'rationalize' all the sex-linked characteristics, including the orange-making genes. In this particular case, suppression of one of the orange-making genes in each cell takes place in a not-quite-random pattern (there is some polygene influence here). Each cell will then carry only one effective orange-making gene.

Since the zygote was only some dozens of cells in size at the time of rationalization, only a few of those cells will eventually determine the color of the coat (the orange-making genes in the other cells will be ignored). If the zygote were homozygous for non-orange, oo, then all cells will contain o, and the coat will be non-orange. Likewise, if the zygote were homozygous for orange, OO, then all cells will contain O, and the coat will be orange. If, however, the zygote were heterozygous, Oo, then some of the cells will contain O and the rest of the cells will contain o. In this case, those portions of the coat determined by O cells will be orange, while those portions determined by o cells will be non-orange. Voila! A tortoiseshell cat!

A female kitten has two X chromosomes, and therefore two orange-making genes, one from each parent. Assuming for the sake of discussion an equal likelihood of inheriting either allele from each parentan assumption that is patently false, but used here for demonstration onlythen one quarter of all females would be non-orange, one-quarter would be orange, and one-half would be tortoiseshell. A male kitten, on the other hand, has only one X chromosome, and therefore only one orange-making gene. Keeping the same false assumption of equal likelihood, then one-half of all males would be non-orange and one-half would be orange. This means that there would be twice as many orange males as females if our assumption were correct.

Our equal-likelihood assumption is not correct, however. The orange-making gene is located adjacent to the centromere and is often damaged during meiosis. This damage tends to make an orange allele into a non-orange allele, giving the non-orange allele a definite leg up, so to speak, in a 7:3 ratio. This means that among female kittens 49% will be non-orange, 42% will be tortoiseshell, and only 9% will be orange, while among male kittens 70% will be non-orange and 30% will be orange: there will be more than 3 times as many orange males as females. That's why there are so many Morris-type males around.

Since a male has only one orange-making gene, there cannot be a male tortie. An exception to this rule is the hermaphrodite, which has an XXY genetic structure. Such a cat can be tortie, since it has two X chromosomes, but is almost invariably sterile. In fact, despite the presence of male genitalia, a hermaphrodite is also an underdeveloped female, and may have both ovaries and testes, with neither fully functional.

6.3.4 The Eight Cat Colors

All possible expressions of the color, orange-making, and color-density genes produce the eight basic coat colors: black, blue (gray), chestnut or chocolate (dark-brown), lavender or lilac (tan), cinnamon (medium brown), fawn (beige), red (orange), and cream.

The brown and dilute colors are rarer (hence generally more prized) because they are recessive. A table of all possible combinations of the three genes controlling color will show all eight basic coat colors, among which are six female or twelve male black cats but only one female or two male fawn.

Note that although tortoiseshell females are two-color they introduce no new colors.

It may also be noted that red and cream dominate any of the true (black or brown) colors: a red coat is red regardless of whether the color gene is black, dark brown, or light brown. The color gene is masked by the orange-making gene. This, coupled with the fact that males are either red or non-red require that the color chart show oO and Oo as distinctly separate. A male has only the first of the two genes: o from oO or O from Oo. In some texts, the orange-making genes are indicated as o(O) and O(o) to emphasize the sexual distinction.

 

Sex BB Bb Bbl bb bbl blbl
ooDD M/F Blk Blk Blk DBr DBr MBr
ooDd M/F Blk Blk Blk DBr DBr MBr
oodd M/F Gry Gry Gry Tan Tan Bge
OoDD M
F
Red
Blk/Red
Red
Blk/Red
Red
Blk/Red
Red
DBr/Red
Red
DBr/Red
Red
MBr/Red
OoDd M
F
Red
Blk/Red
Red
Blk/Red
Red
Blk/Red
Red
DBr/Red
Red
DBr/Red
Red
MBr/Red
Oodd M
F
Crm
Gry/Crm
Crm
Gry/Crm
Crm
Gry/Crm
Crm
Tan/Crm
Crm
Tan/Crm
Crm
Bge/Crm
OODD M/F Red Red Red Red Red Red
OODd M/F Red Red Red Red Red Red
OOdd M/F Crm Crm Crm Crm Crm Crm

The Eight Cat Colors

6.4 The Albinism Gene

The first of the color-conformation genes affect coat pattern is the albinism gene. This gene controls the amount of body color and comes in five alleles: full color, C, Burmese, cb, Siamese, cs, blue-eyed albino, ca, and albino, c.

The full color allele, C is wild, is dominant, and produces a full expression of the coat colors. This is sometimes called the non-albino allele.

The Burmese allele, cb, is mutant, is recessive to the full color allele, codominant with the Siamese allele, and dominant to the blue-eyed albino and albino alleles, and produces a slight albinism, reducing black to a very dark brown, called sable in the Burmese breed, and producing green or green-gold eyes.

The Siamese allele, cs, is mutant, is recessive to the full color allele, codominant with the Burmese allele, and dominant to the blue-eyed albino and albino alleles, and produces an intermediate albinism, reducing the basic coat color from black/brown to a light beige with dark brown 'points' in the classic Siamese pattern and producing bright blue eyes.

The Burmese and Siamese alleles are codominant, that is they each have exactly as much dominance or recessivity. It is possible to have one of each allele, cbcs, producing a Siamese-patterned coat with a darker base body color and turquoise (aquamarine) eyes: the Tonkinese pattern.

The blue-eyed albino allele, ca, is mutant, is recessive to the full color, Burmese and Siamese alleles and dominant to the albino allele, and produces a nearly complete albinism with a translucent white coat and very washed-out pale blue eyes.

The albino allele, c, is mutant, is recessive to all others, and produces a complete albinism with a translucent white coat and pink eyes.

The albinism genes combine in some rather interesting ways:

Notice how the dominance characteristics among the alleles are normal except for the combination of Burmese and Siamese, which produce the Tonkinese pattern.

 

C cb cs ca c
C normal normal normal normal normal
cb normal Burmese Tonkinese Burmese Burmese
cs normal Tonkinese Siamese Siamese Siamese
ca normal Burmese Siamese BE Albino BE Albino
c normal Burmese Siamese BE Albino Albino

The Albinism Gene

6.5 The Agouti Gene

The next gene controlling the pattern of the coat is the agouti gene. This gene will control ticking and comes in two alleles: agouti, A, and non-agouti, a.

The agouti allele, A, is wild, is dominant, and produces a banded or ticked (agouti) hair, which in turn will produce a tabby coat pattern.

The non-agouti allele, a, is mutant, is recessive, and suppresses ticking, which in turn will produce a solid-color coat. This gene only operates upon the color gene (black, dark brown, or light brown) in conjunction with the non-orange allele of the orange-making gene and is masked by the orange allele of the orange-making gene.

6.6 The Tabby Genes

The last of the genes affecting the coat pattern is the tabby gene. This gene will control the actual coat pattern (striped, spotted, solid, etc.) and comes in three alleles: mackerel or striped tabby, T, Abyssinian or all-agouti-tabby, Ta, and blotched or classic tabby, tb.

The mackerel-tabby allele, T, is wild, is co-dominant with the spotted tabby and Abyssinian alleles and dominant to the classic-tabby allele, and produces a striped cat, with vertical non-agouti stripes on an agouti background. This is the most common of all patterns and is typical grassland camouflage, where shadows are long and strait.

A spotted tabby is genetically a striped tabby with the stripes broken up by polygene influence. There is no specific 'spotted-tabby' gene. This spotted coat is a typical forest camouflage, where shadows are dappled by sunlight shining through the trees. Do not confuse the spots of our domestic cats with the rosettes of the true spotted cats: entirely different genes are involved.

The Abyssinian allele, Ta, is mutant, is codominant to the mackerel-tabby allele and dominant to the classic-tabby allele, and will produce an all-agouti coat without stripes or spots. This all-agouti coat is a basic type of bare-ground camouflage, seen in the wild rabbit and many other animals.

A special case occurs when both the mackerel-tabby and Abyssinian alleles are expressed, TTa. This will produce a unique coat consisting of the beige ground color with each hair tipped with the expressed color. By selective breeding, the ground color has become a soft gold, producing the beautiful golden chinchilla cats.

The blotched- or classic-tabby allele, tb, is recessive to both the mackerel-tabby and the Abyssinian alleles and will produce irregular non-agouti blotches or 'cinnamon-roll' sworls on an agouti background. When the 'cinnamon-rolls' are clean and symmetrical, and nicely centered on the sides, a strikingly beautiful coat is achieved.

The 'coat of choice' in Europe is the classic tabby (hence the name), probably because of the similarity in appearance of a large mackerel tabby domestic cat and the European Wildcat, the former being soft and cuddly and the latter prone to remove fingers. In the U.S., the reverse is true.

6.7 The Color-Inhibitor Gene

The first of the color-conformation genes controlling color expression is the color-inhibitor gene. This gene controls the expression of color within the hair and comes in two alleles: the non-inhibitor, i, and the inhibitor, I.

The non-inhibitor allele, i, is wild, is recessive, and allows expression of the color throughout the length of the hair, producing a normally colored coat.

The inhibitor allele, I, is mutant, is dominant, and inhibits expression of the color over a portion of the hair.

The inhibitor allele is variably expressed. When slightly expressed, the short down hairs (underfur) are merely tipped with color, while the longer guard and awn hairs are clear for about the first quarter of their lengths: the coat is said to be smoked. When moderately expressed, the down hairs are completely clear and the longer hairs are clear for about half their lengths: the coat is shaded. When heavily expressed, the down hairs are completely clear and the longer hairs are clear for about three-quarters (or more) of their lengths: the coat is then tipped or chinchilla.

Neither allele has anything to do with the actual color or pattern, only with whether that color is laid upon a clear undercoat or one of the beige ground color.

6.8 The Spotting Gene

The next gene controlling color expression is the white-spotting gene. This gene controls the presence and pattern of white masking the normal coat pattern, and has four alleles: non-spotted, s, spotted, S, particolor, Sp, and Birman, sb. The presence of the particolor and Birman alleles of this gene are still subject to argument at this time: their effect is not.

The non-spotted allele, s, is wild, is recessive, and produces a normal coat without white.

The spotted allele, S, is mutant, is dominant, and produces white spotting that masks the true coat color in the affected area. This is a variably expressed allele with a very wide expression range: from a black cat with one white hair to a white cat with one black hair.

The particolor allele, Sp, if it exists, is a variation of the spotted allele affecting the pattern of white. The classic particolor pattern is an inverted white 'V' starting in the center of the forehead and passing through the centers of the eyes. The chin, chest, belly, legs and feet are white. Variable expressions of this allele range downward to a simple white locket or a white spot on the forehead.

The Birman allele, Sb, if it exists, is a variation of the spotted allele producing white feet. Variable expression ranges from white legs and feet to white toes only.

Unlike the white gene or the albinism gene, the white-spotting gene does not affect eye color: if your all white cat has green eyes, it is most definitely a colored cat with one big white spot all over.

6.9 The Dominant-White Gene

The final gene controlling color expression is the dominant-white gene. This gene determines whether the coat is solid white or not, and comes in three alleles: non-white, w, white, W, and van, Wv. The existence of the van allele is open to argument: it may be a separate gene.

The non-white allele, w, is wild, is recessive, and allows full expression of the coat color and pattern.

The white allele, W, is mutant, is dominant, and produces a translucent all-white coat with either orange or pale blue eyes. Blue-eyed dominant-white cats are often deaf, orange-eyed cats occasionally so. Interestingly, a white cat may be odd-eyed, having one blue and one orange eye. Such a cat is often deaf on the blue side.

The van allele, Wv, if it exists, is a variation of the white allele allowing color in the classic van pattern: on the crown of the head (often two small half-caps separated by a thin white line), on the ears, and on the tail. Variable expression controls cap size and shape and the presence of color on the ears and tail. Occasionally, the caps will be missing and only the ears and/or tail will be colored.

It is important to remember that, genetically speaking, white is not a color, but rather the suppression of the pigment that would normally be present. A heterozygous white cat can and often does produce colored kittens, sometimes with no white at all.

6.10 Polygenes

The genes described above control color and coat, and several breed-specific body features, but what about the genes that control the body structure itself? Can we not develop a cat with long floppy ears (sort of a bassett-cat)? The answer is a qualified no. Not within the realms of normal breeding, and not without a much better means of genetic engineering than is currently available to us. The reason cats (and horses) resist major changes, whereas dogs do not, is because the genes controlling these features are scattered among the genetic codes of other genes (remember, a gene is not a physical entity but rather a series of instructions). This type of scattered gene is called a 'polygene.' Polygenes are in firm control of many of those things that define the cat, and breeding programs can only change these characteristics slowly, bit-by-bit.

7. The Eye Colors

There are no specific genes for the eye colors. Rather, the color of the eyes is intimately linked to the color and pattern of the coat via several polygenes.

 

Eye Color Abr Description
Copper cpr Deep copper-orange
Orange org Bright orange
Amber amb Yellow-orange
Yellow yel Yellow
Gold gld Dark yellow with hint of green
Hazel hzl Dark greenish-yellow
Green grn Green
Turquoise trq Bluish-green(common in Tonkinese)
Siamese Blue sbl Royal Blue to medium grayish-blue
Dominant-White Blue wbl Medium blue
Dominant-White Odd odd One blue, one orange
Albino Blue abl Very pale blue, almost gray
Albino Pink pnk Pink

The Eye Colors

There is much about eye color that is not yet understood. As an example, the British Blue usually has orange or copper eyes while those of the Russian Blue are usually green, in spite of the fact that the breeds have identical coat genotypes.

The range of eye color is from a deep copper-orange through yellow to green. The blue and pink eyed cats are partial or full albinos, with suppression of the eye color.

There is a definite interaction between the color genes, B, b, and bl, the color density genes, D and d, and eye color. This interaction is especially evident in those cats with Siamese coats where the eye color can range from a strikingly deep, rich blue for a Seal Point coat to a medium-pale, grayish blue for a lilac point coat.

8. Naming the Colors

When it came to naming the colors, those who did so were firm believers in using the thesaurus: never call a color brown when you can call it chocolate or cinnamon.

The colors naturally fall into distinct groups: the 'standard' colors, the shaded colors, the 'exotic' colors, the oriental colors, and the whites. Each group may then be subdivided into several distinct smaller groups, each with a common characteristic. Each color name is followed by its karyotype in three groups (as they were discussed above), and the usual eye colors. Bear in mind that all possible combinations of color and pattern will eventually be realized, but not necessarily recognized: especially by the various cat fancies.

9. The Standard Colors

The standard colors form the basis for all other colors in nomenclature and karyotypes. The following descriptions of the standard colors are representative of the colors as used with various breeds. No attempt has been made to provide an exhaustive listing.

Since the orange-making allele, O, and orange suppression allele, o, are only found on the X chromosome, this is expressed in males as a single O or o, and in females as a double OO or oo. This is indicated in the following tables as O or o for those color groups not incorporating either tortoiseshell or calico.

A color group having tortoiseshell or calico colors has both the orange-making allele, O, and orange suppression allele, o. These alleles are only found on the X chromosome. Therefore, tortoiseshell and calico colors are only found on females (XX) and hermaphrodites (XXY).

9.1 The Standard Solid Colors

The standard solid or self colors are the fundamental rendition of the eight basic coat colors. Solid colors are called 'self colours' in Britain.

The blacks technically have brown undercoats, but selective breeding has managed to eliminate the brown undercoat and has produced cats that are 'black to the bone.'

The subtle differences possible in blues (grays) has made this one of the most popular colors among breeders, with several breeds being exclusively blue. Blues, regardless of pattern, are often referred to as 'dilutes.'

The terms 'chestnut' and 'chocolate' are synonymous, as are the terms 'lavender' and 'lilac.' Some breeds are called 'chestnuts,' and other breeds may be called 'chocolates.' The genes are the same.

Since the orange-making gene, OO, also masks the non-agouti allele, a, of the agouti gene, red and cream solids are genetically identical to red and cream tabbies. Careful selective breeding has made the non-agouti areas (the stripes) to widen and overlap, effectively canceling the paler agouti background and obscuring the tabby pattern. A generation or two of random breeding, however, and the stripes will return.

 

karyotype
color genes pattern genes expression genes
solid or self color dense orange albino agouti tabby inhib spot domW usual eyes
black black s. B* D* o C* aa ** ii ss ww cpr org grn
dk brn chestnut s. b* D* o C* aa ** ii ss ww cpr org
lt brn cinnamon s. blbl D* o C* aa ** ii ss ww org
orange red s. ** D* O C* ** T* ii ss ww cpr org
gray blue s. B* dd o C* aa ** ii ss ww cpr org grn
tan lavender s. b* dd o C* aa ** ii ss ww cpr org gld
beige fawn s. blbl dd o C* aa ** ii ss ww org gld
cream cream s. ** dd O C* ** T* ii ss ww cpr org

The Standard Solid Colors

9.2 The Standard Patch Colors

The standard patch colors, also called solid-and-white colors or bicolors, are formed by combining the white-spotting gene, S*, with the standard solid colors.

If, instead of the normal random white spotting gene, the particolor gene, Sp*, is present, then the coat will show white in the particolor pattern.

If both the random white-spotting and particolor genes, SSp, are present, then a composite pattern will be evident.

If the Birman gene, sbsb, is present, then the pattern will be white feet only.

 

karyotype
color genes pattern genes expression genes
patch color dense orange albino agouti tabby inhib spot domW usual eyes
black black p. B* D* o C* aa ** ii S* ww cpr org grn
dk brn chestnut p. b* D* o C* aa ** ii S* ww cpr org
lt brn cinnamon p. blbl D* o C* aa ** ii S* ww org
orange red p. ** D* O C* ** T* ii S* ww cpr org
gray blue p. B* dd o C* aa ** ii S* ww cpr org grn
tan lavender p. b* dd o C* aa ** ii S* ww cpr org gld
beige fawn p. blbl dd o C* aa ** ii S* ww GENEorg gld
cream cream p. ** dd O C* ** T* ii S* ww cpr org

The Standard Patch Colors

9.3 The Standard Tortoiseshell Colors

The standard tortoiseshell colors, also called the torbie colors, are formed by combining both the dominant and recessive sex-linked orange genes, Oo, with the standard solid colors.

A tabby pattern may be visible in the orange areas, with any tabby pattern being permitted. In some individuals, the agouti and non-agouti orange areas may offer such contrast as to produce a false tri-color (black-orange-cream).

 

karyotype
color genes pattern genes expression genes
tortie color dense orange albino agouti tabby inhib spot domW usual eyes
black tortie B* D* Oo C* aa T* ii ss ww cpr org
dk brn chestnut t. b* D* Oo C* aa T* ii ss ww cpr org
lt brn cinnamon t. blbl D* Oo C* aa T* ii ss ww org
orange
gray blue t. B* dd Oo C* aa T* ii ss ww cpr org grn
tan lavender t. b* dd Oo C* aa T* ii ss ww cpr org grn
beige fawn t. blbl dd Oo C* aa T* ii ss ww org grn
cream

The Standard Tortoiseshell Colors

9.4 The Standard Calico Colors

The standard calico colors, also called the tortoiseshell-and-white colors, are formed by combining both the dominant and recessive sex-linked orange-making genes, Oo, with the standard patch colors. As with the standard patch colors, any white-spotting pattern is permitted.

 

karyotype
color genes pattern genes expression genes
calico color dense orange albino agouti tabby inhib spot domW usual eyes
black calico. B* D* Oo C* aa T* ii S* ww cpr org
dk brn chestnut cs. b* D* Oo C* aa T* ii S* ww cpr org
lt brn cinnamon c. blbl D* Oo C* aa T* ii S* ww org
orange
gray blue c. B* dd Oo C* aa T* ii S* ww cpr org grn
tan lavender c. b* dd Oo C* aa T* ii S* ww cpr org grn
beige fawn c. blbl dd Oo C* aa T* ii S* ww org grn
cream

The Standard Calico Colors

9.5 The Standard Tabby Colors

The standard tabby colors are formed by adding the agouti gene, A*, to the solids. This causes the otherwise solid color to show the pattern dictated by the tabby gene: light and dark stripes (mackerel allele, T*) or blotches (blotched allele, tbtb).

The brown tabby corresponds to the black solid: sufficient undercoat color shows in the agouti areas to provide a brownish cast. When in mackerel pattern, this is the 'all wild' genotype, and represents the natural state of the domestic cat.

The red tabby, when in mackerel pattern, presents an alternate stable coat often found on feral domestic cats, usually as a pale ginger.

 

karyotype
color genes pattern genes expression genes
tabby color dense orange albino agouti tabby inhib spot domW usual eyes
black brown t. B* D* o C* A* T* ii ss ww cpr org yel hzl
dk brn chestnut t. b* D* o C* A* T* ii ss ww cpr org yel hzl
lt brn cinnamon t. blbl D* o C* A* T* ii ss ww org yel hzl
orange red t. ** D* O C* ** T* ii ss ww cpr org yel hzl
gray blue t. B* dd o C* A* T* ii ss ww cpr org yel hzl
tan lavender t. b* dd o C* A* T* ii ss ww cpr org yel hzl
beige fawn t. blbl dd o C* A* T* ii ss ww org yel hzl
cream cream t. ** dd O C* ** T* ii ss ww cpr org yel hzl

The Standard Tabby Colors

9.6 The Standard Tabby-Patch Colors

The standard tabby patch colors are formed by combining the white spotting gene, S*, with the standard tabby colors. As with the standard patch colors, any white-spotting pattern is permitted.

 

karyotype
color genes pattern genes expression genes
tabby patch color dense orange albino agouti tabby inhib spot domW usual eyes
black brown t. p. B* D* o C* A* T* ii S* ww cpr org yel hzl
dk brn chestnut t. p. b* D* o C* A* T* ii S* ww cpr org yel hzl
lt brn cinnamon t. p. blbl D* o C* A* T* ii S* ww org yel hzl
orange red t. p. ** D* O C* ** T* ii S* ww cpr org yel hzl
gray blue t. p. B* dd o C* A* T* ii S* ww cpr org yel hzl
tan lavender t. p. b* dd o C* A* T* ii S* ww cpr org yel hzl
beige fawn t. p. blbl dd o C* A* T* ii S* ww org yel hzl
cream cream t. p. ** dd O C* ** T* ii S* ww cpr org yel hzl

The Standard Tabby Patch Colors

9.7 The Standard Tabby-Tortoiseshell Colors

The standard tabby-tortoiseshell colors, also called the torbie colors, are formed by combining both the dominant and recessive sex-linked orange genes, Oo, with the standard tabby colors.

 

karyotype
color genes pattern genes expression genes
torbie color dense orange albino agouti tabby inhib spot domW usual eyes
black torbie B* D* Oo C* A* T* ii ss ww cpr org grn
dk brn chestnut t. b* D* Oo C* A* T* ii ss ww cpr org
lt brn cinnamon t. blbl D* Oo C* A* T* ii ss ww org
orange
gray blue t. B* dd Oo C* A* T* ii ss ww cpr org grn
tan lavender t. b* dd Oo C* A* T* ii ss ww cpr org gld
beige fawn t. blbl dd Oo C* A* T* ii ss ww org gld
cream

The Standard Tabby-Tortoiseshell Colors

9.8 The Standard Tabby-Calico Colors

The standard tabby-calico colors, also called the tabby-tortoiseshell-patch colors, torbie-patch colors, or torbico colors, are formed by combining the dominant and recessive orange-making genes, Oo, with the standard tabby patch colors.

 

karyotype
color genes pattern genes expression genes
torbico color dense orange albino agouti tabby inhib spot domW usual eyes
black torbico B* D* Oo C* A* T* ii S* ww cpr org yel hzl
dk brn chestnut t. b* D* Oo C* A* T* ii S* ww cpr org yel hzl
lt brn cinnamon t. blbl D* Oo C* A* T* ii S* ww org yel hzl
orange
gray blue t. B* dd Oo C* A* T* ii S* ww cpr org yel hzl
tan lavender t. b* dd Oo C* A* T* ii S* ww cpr org yel hzl
beige fawn t. blbl dd Oo C* A* T* ii S* ww org yel hzl
cream

The Standard Tabby-Calico Colors

10. The Specific Tabby Colors

The specific tabby colors have unusually striking patterns and contrasts. Being tabby colors, these colors are most often used with shorthaired breeds where the patterns are completely revealed. The abyssinian colors are shared between the shorthaired Abyssinian and the longhaired Somali. The following descriptions of the specific tabby colors are representative of the colors as used with various breeds. No attempt has been made to provide an exhaustive listing.

NOTE: Since the orange-making allele, O, and orange suppression allele, o, are only found on the X chromosome, this is expressed in males as a single O or o, and in females as a double OO or oo. This is indicated in the following tables as O or o for those color groups not incorporating either tortoiseshell or calico.

A color group having tortoiseshell or calico colors has both the orange-making allele, O, and orange suppression allele, o. These alleles are only found on the X chromosome. Therefore, tortoiseshell and calico colors are only found on females (XX) and hermaphrodites (XXY).

10.1 The Bronze Tabby Colors

The bronze tabby colors are formed by exagerating standard tabby colors through the effects of various polygenes. Ideal coats have striking patterns against an even agaouti ground color. The bronze spotted tabby colors are bronze tabby colors with the mackerel striping broken into spots. Ideal coats have evenly spaced round spots on a solid agouti ground color. Only six of the eight possible colors are recognized.

 

karyotype
color genes pattern genes expression genes
bronze tabby color dense orange albino agouti tabby inhib spot domW usual eyes
black bronze tabby B* D* o C* A* T* ii ss ww gld
dk brn b. chocolate t. b* D* o C* A* T* ii ss ww cpr gld
lt brn blbl D* o C* A* T* ii ss ww
orange copper t. ** D* O C* ** T* ii ss ww cop
gray b. blue t. B* dd o C* A* T* ii ss ww cpr gld
tan b. lavender t. b* dd o C* A* T* ii ss ww cpr gld
beige blbl dd o C* A* T* ii ss ww
cream b. cream t. ** dd O C* ** T* ii ss ww gld

The Bronze Tabby Colors

10.2 The Silver Tabby Colors

The silver tabby colors are formed by adding a moderate expression of the inhibitor gene, I*, to the bronze tabby colors. The silver spotted tabby colors are silver tabby colors with the mackerel striping broken into spots. Ideal coats have jet black spots on a silvery agouti background. Only six of the eight possible colors are recognized.

 

karyotype
color genes pattern genes expression genes
silver tabby color dense orange albino agouti tabby inhib spot domW usual eyes
black silver tabby. B* D* o C* A* T* I* ss ww hzl grn
dk brn s. chestnut t. b* D* o C* A* T* I* ss ww hzl grn
lt brn blbl D* o C* A* T* I* ss ww
orange s. red t. ** D* O C* ** T* I* ss ww hzl grn
gray s. blue t. B* dd o C* A* T* I* ss ww hzl grn
tan s. lilac t. b* dd o C* A* T* I* ss ww hzl grn
beige blbl dd o C* A* T* I* ss ww
cream s. cream t. ** dd O C* ** T* I* ss ww hzl grn

The Silver Tabby Colors

10.3 The Abyssinian Colors

The abyssinian colors are standard tabby colors with the Abyssinian allele of the tabby gene, Ta*. This produces an all-agouti coat, similar to that of the wild rabbit. It should be noted that among the abyssinian colors there are two genetically different 'reds.' The two 'reds' are virtually identical in appearance: 'red,' which is in reality cinnamon, and 'true red,' which is red.

 

karyotype
color genes pattern genes expression genes
abyssinian color dense orange albino agouti tabby inhib spot domW usual eyes
black ruddy a. B* D* o C* A* Ta* ii ss ww org amb grn
dk brn chestnut a. b* D* o C* A* Ta* ii ss ww org amb grn
lt brn red a. blbl D* o C* A* Ta* ii ss ww org amb
orange true red a. ** D* O C* ** Ta* ii ss ww cpr org amb
gray blue a. B* dd o C* A* Ta* ii ss ww org amb grn
tan lavender a. b* dd o C* A* Ta* ii ss ww org amb grn
beige fawn a. blbl dd o C* A* Ta* ii ss ww org amb
cream cream a. ** dd O C* ** Ta* ii ss ww cpr org amb

The Abyssinian Colors

10.4 The Silver Abyssinian Colors

The silver Abyssinian colors are formed by adding a moderate expression of the inhibitor gene, I* to the abyssinian colors. This produces the all-agouti ticking on a pale silver undercolor.

 

karyotype
color genes pattern genes expression genes
silver abyssinian color dense orange albino agouti tabby inhib spot domW usual eyes
black silver abyssinian B* D* o C* A* Ta* I* ss ww grn
dk brn s. chestnut a. b* D* o C* A* Ta* I* ss ww grn
lt brn s. red a. blbl D* o C* A* Ta* I* ss ww yel
orange true s. red a. ** D* O C* ** Ta* I* ss ww org yel
gray s. blue a. B* dd o C* A* Ta* I* ss ww grn
tan s. lilac a. b* dd o C* A* Ta* I* ss ww grn
beige s. fawn a. blbl dd o C* A* Ta* I* ss ww yel
cream s. cream a. ** dd O C* ** Ta* I* ss ww org yel

The Silver Abyssinian Colors

11. The Shaded Colors

The shaded colors are formed by adding an expression of the color inhibitor gene, I*, to the standard colors. This causes a loss of color in a portion of each hair, and produces a stricking coat. The shaded colors are most often used with longhaired breeds, typically the Persian. The following descriptions of the shaded colors is representative of the colors as used with various breeds. No attempt has been made to provide an exhaustive listing.

NOTE: Since the orange-making allele, O, and orange suppression allele, o, are only found on the X chromosome, this is expressed in males as a single O or o, and in females as a double OO or oo. This is indicated in the following tables as O or o for those color groups not incorporating either tortoiseshell or calico.

A color group having tortoiseshell or calico colors has both the orange-making allele, O, and orange suppression allele, o. These alleles are only found on the X chromosome. Therefore, tortoiseshell and calico colors are only found on females (XX) and hermaphrodites (XXY).

11.1 The Smoke Colors

The smoke colors are formed by adding a light expression of the inhibitor gene, I*, to the standard solid colors. This causes the root of each hair to become colorless, while the bulk of the coat is colored. Only six of the eight possible colors are recognized.

 

karyotype
color genes pattern genes expression genes
smoke color dense orange albino agouti tabby inhib spot domW usual eyes
black (silver) s. B* D* o C* aa ** I* ss ww cpr org yel
dk brn chestnut s. b* D* o C* aa ** I* ss ww cpr org yel
lt brn blbl D* o C* aa ** I* ss ww
orange red s. ** D* O C* ** T* I* ss ww cpr org yel
gray blue s. B* dd o C* aa ** I* ss ww cpr org yel
tan lavender s. b* dd o C* aa ** I* ss ww cpr org yel
beige blbl dd o C* aa ** I* ss ww
cream cream s. ** dd O C* ** T* I* ss ww cpr org yel

The Smoke Colors

11.2 The Shade Colors

The shade colors are formed by adding a moderate expression of the inhibitor gene, I*, to the standard solid colors. This causes about half of each hair to become colorless. Only six of the eight possible colors are recognized.

 

karyotype
color genes pattern genes expression genes
shade color dense orange albino agouti tabby inhib spot domW usual eyes
black (silver) s. B* D* o C* aa ** I* ss ww cpr grn
dk brn chestnut s. b* D* o C* aa ** I* ss ww cpr grn
lt brn blbl D* o C* aa ** I* ss ww
orange red s. ** D* O C* ** T* I* ss ww cpr grn
gray blue s. B* dd o C* aa ** I* ss ww cpr grn
tan lavender s. b* dd o C* aa ** I* ss ww cpr grn
beige blbl dd o C* aa ** I* ss ww
cream cream s. ** dd O C* ** T* I* ss ww cpr grn

The Shade Colors

11.3 The Chinchilla Colors

The chinchilla colors are formed by adding a heavy expression of the inhibitor gene, I*, to the standard solid colors. This causes all but the tip of each hair to become colorless. Only six of the eight possible colors are recognized

 

karyotype
color genes pattern genes expression genes
chinchilla color dense orange albino agouti tabby inhib spot domW usual eyes
black (silver) c. B* D* o C* aa ** I* ss ww grn
dk brn chestnut c. b* D* o C* aa ** I* ss ww grn
lt brn blbl D* o C* aa ** I* ss ww
orange red c. ** D* O C* ** T* I* ss ww grn
gray blue c. B* dd o C* aa ** I* ss ww grn
tan lavender c. b* dd o C* aa ** I* ss ww grn
beige blbl dd o C* aa ** I* ss ww
cream cream c. ** dd O C* ** T* I* ss ww grn

The Chinchilla Colors

11.4 The Tortoiseshell Chinchilla Colors

The tortoiseshell chinchilla colors are formed by adding a moderate-to heavy expression of the inhibitor gene, I*, to the standard tortoiseshell colors. This causes all but the tip of each hair to become colorless. Only four of the six possible colors are recognized.

 

karyotype
color genes pattern genes expression genes
tortie chinchilla color dense orange albino agouti tabby inhib spot domW usual eyes
black tortie chinchilla. B* D* Oo C* aa T* I* ss ww cpr org yel
dk brn chestnut t. c. b* D* Oo C* aa T* I* ss ww cpr org yel
lt brn blbl D* Oo C* aa T* I* ss ww
orange
gray blue t. c. B* dd Oo C* aa T* I* ss ww cpr org yel
tan lavender t. c. b* dd Oo C* aa T* I* ss ww cpr org yel
beige blbl dd Oo C* aa T* I* ss ww
cream

The Tortoiseshell Chinchilla Colors

11.5 The Golden Chinchilla Colors

The golden chinchilla colors are formed by adding a moderate-to heavy expression of the inhibitor gene, I*, to the standard solid colors, while simultaneously combining the mackerel and Abyssinian alleles of the tabby gene, TTa. This produces a coat of undercoat-colored hairs tipped with the standard colors. Selective breeding has altered the undercoat polygenes to produce a striking warm-gold color. Only three of the eight possible colors are recognized. Only three of the eight possible colors are recognized.

 

karyotype
color genes pattern genes expression genes
golden chinchilla color dense orange albino agouti tabby inhib spot domW usual eyes
black golden c. B* D* o C* A* TTa I* ss ww gld
dk brn honey c. b* D* o C* A* TTa I* ss ww gld
lt brn blbl D* o C* A* TTa I* ss ww
orange copper c. ** D* O C* ** TTa I* ss ww cpr gld
gray B* dd o C* A* TTa I* ss ww
tan b* dd o C* A* TTa I* ss ww
beige blbl dd o C* A* TTa I* ss ww
cream ** dd O C* ** TTa I* ss ww

The Golden Chinchilla Colors

11.6 The Golden Tortoiseshell Chinchilla Colors

The golden tortoiseshell chinchilla colors are formed by adding a moderate-to heavy expression of the inhibitor gene, I*, to the standard tortiseshell colors, while simultaneously combining the mackerel and Abyssinian alleles of the tabby gene, TTa. This produces a coat with hairs of undercoat color tipped with the standard tortie colors. Only two of the six possible colors are recognized.

 

karyotype
color genes pattern genes expression genes
golden tortie chinchilla color dense orange albino agouti tabby inhib spot domW usual eyes
black golden t. c. B* D* Oo C* A* TTa I* ss ww gld
dk brn honey t. c. b* D* Oo C* A* TTa I* ss ww gld
lt brn blbl D* Oo C* A* TTa I* ss ww
orange
gray B* dd Oo C* A* TTa I* ss ww
tan b* dd Oo C* A* TTa I* ss ww
beige blbl dd Oo C* A* TTa I* ss ww
cream

The Golden Tortoiseshell Chinchilla Colors

12. The Oriental Colors

The Oriental colors are those colors most-often associated with cats of Oriental build. The following descriptions of the oriental colors are representative of the colors as used with various breeds. No attempt has been made to provide an exhaustive listing.

NOTE: Since the orange-making allele, O, and orange suppression allele, o, are only found on the X chromosome, this is expressed in males as a single O or o, and in females as a double OO or oo. This is indicated in the following tables as O or o for those color groups not incorporating either tortoiseshell or calico.

A color group having tortoiseshell or calico colors has both the orange-making allele, O, and orange suppression allele, o. These alleles are only found on the X chromosome. Therefore, tortoiseshell and calico colors are only found on females (XX) and hermaphrodites (XXY).

12.1 The Oriental Solid Colors

The Oriental solid colors are identical to the standard solid colors except for their names. Oriental color names tend to be used with cats of oriental build, effectively solid-color Siamese.

 

karyotype
color genes pattern genes expression genes
oriental color dense orange albino agouti tabby inhib spot domW usual eyes
black ebony B* D* o C* aa ** ii ss ww grn
dk brn chocolate b* D* o C* aa ** ii ss ww grn
lt brn caramel blbl D* o C* aa ** ii ss ww grn
orange red ** D* O C* ** T* ii ss ww grn
gray blue B* dd o C* aa ** ii ss ww grn
tan lilac b* dd o C* aa ** ii ss ww grn
beige fawn blbl dd o C* aa ** ii ss ww grn
cream cream ** dd O C* ** T* ii ss ww grn

The Oriental Colors

12.2 The Burmese Colors

The Burmese colors are formed from the standard solid colors by the reduction in color expression from full, C*, to the Burmese alleles, cbcb. This is a partial albinism and causes a slight reduction in color intensity: black becomes sable. These colors are used almost exclusively for the Burmese and related breeds, such as the Malayan and Tiffany.

 

karyotype
color genes pattern genes expression genes
burmese color dense orange albino agouti tabby inhib spot domW usual eyes
black sable B* D* o cbcb aa ** ii ss ww gld
dk brn champagne b* D* o cbcb aa ** ii ss ww gld
lt brn cinnamon blbl D* o cbcb aa ** ii ss ww gld
orange red ** D* O cbcb ** T* ii ss ww gld
gray blue B* dd o cbcb aa ** ii ss ww gld
tan platinum b* dd o cbcb aa ** ii ss ww gld
beige fawn blbl dd o cbcb aa ** ii ss ww gld
cream cream ** dd O cbcb ** T* ii ss ww gld

The Burmese Colors

12.3 The Tonkinese Colors

The Tonkinese colors are formed from the standard solid colors by the reduction of color expression from full, C*, to the combined Burmese and Siamese alleles, cbcs. This is a partial albinism and causes a downgrade in color expression, the body color becoming a light-to-medium brown and the points becoming Burmese. These colors are used only with the Tonkinese breed.

 

karyotype
color genes pattern genes expression genes
tonkinese color dense orange albino agouti tabby inhib spot domW usual eyes
black natural mink B* D* o cbcs aa ** ii ss ww trq
dk brn honey mink b* D* o cbcs aa ** ii ss ww trq
lt brn cinnamon mink blbl D* o cbcs aa ** ii ss ww trq
orange red mink ** D* O cbcs ** T* ii ss ww trq
gray blue mink B* dd o cbcs aa ** ii ss ww trq
tan champagne mink b* dd o cbcs aa ** ii ss ww trq
beige fawn mink blbl dd o cbcs aa ** ii ss ww trq
cream cream mink ** dd O cbcs ** T* ii ss ww trq

The Tonkinese Colors

12.4 The Siamese Colors

The Siamese colors are formed from the standard solid colors by the reduction of color expression from full, C*, to the Siamese alleles, cscs. This is a partial albinism and causes a downgrade in color expression, the body color becoming fawn and the points becoming Burmese. Only six of the eight possible Siamese colors are recognized.

 

karyotype
color genes pattern genes expression genes
solid (point) color dense orange albino agouti tabby inhib spot domW usual eyes
black seal point B* D* o cscs aa ** ii ss ww sbl
dk brn chocolate point b* D* o cscs aa ** ii ss ww sbl
lt brn blbl D* o cscs aa ** ii ss ww
orange red point ** D* O cscs ** T* ii ss ww sbl
gray blue point B* dd o cscs aa ** ii ss ww sbl
tan lilac point b* dd o cscs aa ** ii ss ww sbl
beige blbl dd o cscs aa ** ii ss ww
cream cream point ** dd O cscs ** T* ii ss ww sbl

The Siamese Colors

12.5 The Tortoiseshell-Point Siamese Colors

The tortoiseshell-point Siamese colors, or tortie-point Siamese Colors, are formed from the standard tortoiseshell colors by the reduction of color expression from full, C*, to the Siamese alleles, cscs. This is a partial albinism and causes a downgrade in color expression, the body color becoming fawn and the points becoming Burmese. Only four of the six possible tortie-point colors are recognized. Only four of the six possible tortoiseshell-point Siamese colors are recognized.

 

karyotype
color genes pattern genes expression genes
tortie point color dense orange albino agouti tabby inhib spot domW usual eyes
black seal t. p. B* D* Oo cscs aa T* ii ss ww sbl
dk brn chocolate t. p. b* D* Oo cscs aa T* ii ss ww sbl
lt brn blbl D* Oo cscs aa T* ii ss ww
orange
gray blue t. p. B* dd Oo cscs aa T* ii ss ww sbl
tan lilac t. p. b* dd Oo cscs aa T* ii ss ww sbl
beige blbl dd Oo cscs aa T* ii ss ww
cream

The Tortoiseshell-Point Siamese Colors

12.6 The Lynx-Point Siamese Colors

The lynx-point Siamese colors, or lynx-point siamese colors, are formed from the standard tabby colors by the reduction of color expression from full, C*, to the Siamese alleles, cscs. This is a partial albinism and causes a downgrade in color expression, the body color becoming fawn and the points becoming Burmese. Only six of the eight possible lynx-point Siamese colors are recognized.

 

karyotype
color genes pattern genes expression genes
lynx point color dense orange albino agouti tabby inhib spot domW usual eyes
black seal l. p. B* D* o cscs A* T* ii ss ww sbl
dk brn chocolate l. p. b* D* o cscs A* T* ii ss ww sbl
lt brn blbl D* o cscs A* T* ii ss ww
orange red l. p. ** D* O cscs A* T* ii ss ww sbl
gray blue l. p. B* dd o cscs A* T* ii ss ww sbl
tan lilac l. p. b* dd o cscs A* T* ii ss ww sbl
beige blbl dd o cscs A* T* ii ss ww
cream cream l. p. ** dd O cscs A* T* ii ss ww sbl

The Lynx-Point Siamese Colors

12.7 The Tabby-Tortoiseshell-Point Siamese Colors

The tabby-tortoiseshell-point Siamese colors, or torbie-point Siamese colors, are formed from the standard tabby-tortoiseshell colors by the reduction of color expression from full, C*, to the Siamese alleles, cscs. This is a partial albinism and causes a downgrade in color expression, the body color becoming fawn and the points becoming Burmese. Only four of the six possible tabby-tortoiseshell-point Siamese colors are recognized.

 

karyotype
color genes pattern genes expression genes
torbie point color dense orange albino agouti tabby inhib spot domW usual eyes
black seal t. p. B* D* OO cscs A* T* ii ss ww sbl
dk brn chocolate t. p. b* D* Oo cscs A* T* ii ss ww sbl
lt brn blbl D* Oo cscs A* T* ii ss ww
orange
gray blue t. p. B* dd Oo cscs A* T* ii ss ww sbl
tan lilac t. p. b* dd Oo cscs A* T* ii ss ww sbl
beige blbl dd Oo cscs A* T* ii ss ww
cream

The Tabby-Tortoiseshell-Point Siamese Colors

13. The White Colors

The white colors produce all-white coats (with the exception of the Van colors). The following descriptions of the white colors is representative of the colors as used with various breeds. No attempt has been made to provide an exhaustive listing.

NOTE: Since the orange-making allele, O, and orange suppression allele, o, are only found on the X chromosome, this is expressed in males as a single O or o, and in females as a double OO or oo. This is indicated in the following tables as O or o for those color groups not incorporating either tortoiseshell or calico.

13.1 The Van Colors

The van colors are formed from the standard solid colors by the van gene, Wv. This is a masking gene, covering the effects of the albino (except for bue-eyed and true albino colors, cb* and cc), agouti, tabby, inhibitor, and white-spotting genes. The van gene, a modified dominant-white gene, causes the coat to be white with color on the crown of the head, ears, and tail only. The preferred van color is auburn (orange). The tail is often tabby-ringed.

 

karyotype
color genes pattern genes expression genes
van color dense orange albino agouti tabby inhib spot domW usual eyes
black black van B* D* o ** ** ** ** ** Wv* org wbl odd
dk brn chestnut van b* D* o ** ** ** ** ** Wv* org wbl odd
lt brn cinnamon van blbl D* o ** ** ** ** ** Wv* org wbl odd
orange auburn van ** D* O ** ** ** ** ** Wv* org wbl odd
gray blue van B* dd o ** ** ** ** ** Wv* org wbl odd
tan lavender van b* dd o ** ** ** ** ** Wv* org wbl odd
beige fawn van blbl dd o ** ** ** ** ** Wv* org wbl odd
cream cream van ** dd O ** ** ** ** ** Wv* org wbl odd

The Van Colors

13.2 The Full-Inhibited While Color

The full-inhibited white color is not a color, but rather a masking of the color genes resulting in an absence of color. The full-inhibited white color is formed by a 100% expression of the inhibitor gene, I*, which masks all colors and patterns except spotted white, dominant white, blue-eyed albino white, and albino white.

Since the current trend in chinchilla coats is to have just a hint of tipping, certain kittens are bound to be born where the 'hint' is effectively zero, creating an all-white cat. Since the colors still exist, the eyes will be the proper color for the masked 'true' coat colors, and may be anything except dominant-white blue, albino blue, or pink.

 

karyotype
color genes pattern genes expression genes
white color dense orange albino agouti tabby inhib spot domW usual eyes
any full-inhibited w. ** ** ** ** ** ** I* ss ww any

The Full-Inhibited White Color

13.3 The Full-Spotted White Color

The full-spotted white color is not a color, but rather a masking of the color genes resulting in an absence of color. The full-spotted white color is formed by a 100% expression of the white spotting gene, S*, which masks all colors and patterns except dominant white, blue-eyed albino white, and albino white.

A full-spotted white coat may have a few non-white hairs, especially on a kitten. Since the colors still exist, the eyes will be the proper color for the masked 'true' coat colors, and may be anything except dominant-white blue, albino blue, or pink.

 

karyotype
color genes pattern genes expression genes
white color dense orange albino agouti tabby inhib spot domW usual eyes
any full-spotted w. ** ** ** ** ** ** ** S* ww any

The Full-Spotted White Color

13.4 The Dominant White Color

The dominant white color is not a color, but rather a masking of the color genes resulting in an absence of color. The dominant white color is formed by the dominant-white gene, W*, which masks all colors and patterns except blue-eyed albino white and albino white. The eyes are always orange, dominant-white blue, or odd (one of each).

 

karyotype
color genes pattern genes expression genes
white color dense orange albino agouti tabby inhib spot domW usual eyes
any dominant w. ** ** ** ** ** ** ** ** W* org wbl odd

The Dominant White Color

13.5 The Blue-Eyed Albino White Color

The blue-eyed albino white color is not a color, but rather a masking of the color genes resulting in an absence of color. The blue-eyed albino white color is formed by the blue-eyed albino allele of the albino gene, ca*, which masks all colors and patterns except albino white. The eyes are always albino blue.

 

karyotype
color genes pattern genes expression genes
albino white color dense orange albino agouti tabby inhib spot domW usual eyes
any blue-eyed a. w. ** ** ** ca* ** ** ** ** ** abl

The Blue-Eyed Albino White Color

13.6 The Albino White Color

The albino white color is not a color, but rather a masking of the color genes resulting in an absence of color. The albino white color is formed by the albino allele of the albino gene, cc, which masks all other colors and patterns. The eyes are always pink.

 

karyotype
color genes pattern genes expression genes
albino white color dense orange albino agouti tabby inhib spot domW usual eyes
any albino white ** ** ** cc ** ** ** ** ** pnk

The Albino White Color

1989-2003 R. Roger Breton and Nancy J. Creek


 Breeders Assistant for Cats Pedigree Software