There are about 70 breeds of cats nowadays, most recognized by all clubs of cat-fanciers, few - by single organizations only. A whole series of breeds that are cultivated in different European and American nurseries are waiting for their recognition and develop in the course of a separate group called " A Group of New Breeds". Some purebred cats are real leaders, for example Persians and Britains, which are under selection for hundred of years. But they include newcomers whose "age" is under ten years as well. The mutation boom of 50ths promoted the revealing and registration of some new breeds: Rexes, Kels, Sphinxes, and so on.
Every continent, every region of the world has its own favorite domestic animals, ordinary pussies and doggies that occur to be special, foreign breeds. So, what is "breed"?
A breed is a quite numerous group of domestic animals, historically formed as a result of a human selection (deliberate or accidental) with the same origin and the same physiological, morphological and exterior characters and peculiarities.
Primitive, local breeds of domestic cats that have been cultivated recently, are formed unconsciously and spontaneously, especially in Russia.
Cultivated, selective breeds, brought mostly from Europe and USA, have disclosed to us the cat as a special world. First of them were Siamese cats of Sergey V. Obrastsov. Persians, Exotics, and others have appeared much later.
The group of "New Breeds of Cats" as a result of directional selection is absolutely unknown in Russia.
Within every breed there cats distinguished by the same color, pattern of hair and corresponding color of eyes. They are united in a certain variety. And very few breeds are cultivated in single or several (two-three) colors only. Cats of a given color are divided in compliance with their sex, age and exhibition classes to provide equal conditions during examination and definition of winners of competitions. For the convenience of a data processing the FIFe created an EML system of breeds and colors coding. Most American organizations denote breeds by two letters in contrast to tree-letter system of FIFe. Because we have many cats form FIFe we also use this system and so escape from alternative versions while studying pedigrees. There's no monopoly of knowledge but the authorship of FIFe is recognized and held in respect by both colleagues and competitors.
Before we had revealed the mysterious world of Pussy that seemed to be so ordinary but so unexpected, we were stroked by the sparkling rainbow of its colors with such delicate and musical names. Not only Mother Nature produced many colorings but humans as well with their indefatigable desire to create and keep a suddenly twinkled color or tone. Nevertheless cat colorings form several clear groups:
1. Solid - white, one-color, tortoise.
2. Ticking - aguthy, tabby.
3. Tipping.
4. Selia, or Burmese color.
5. Color-point.
6. Bicolors and particolors.
Let's view following colorings: solid, self, traditional division.
1. White: white with blue eyes - w 61; white with red eyes, white with cupper eyes - w 64; white with cobalt-blue eyes (color-point) - w 67.
2. One-color: ebony, black - n; chocolate, chestnut, brown - b; cinnamon - o; blue - d; lavender, lilac - c; fawn, caramel, light-lilac - p; red - d; cream - e.
3. Tortoises or torti: tortoise (red-black) - f; chocolate-tortoise - h; cinnamon-tortoise - q; blue-cream - g; lilac-cream, lilac-tortoise - j.
General requirements to colorings of solid group:
- the same tone of coloring on all parts of head, body, limbs and tail;
- the same tone of coloring along the length of hair (nap and down);
- the same tone of coloring of nap and underhair (more delicate structure of down provides smaller amount of pigment inside and leads to some clarification of coloring, but with no proclaimed contrast);
- the same coloring of a hair and bald regions: tip of nose, edging of eyes and lips, and pads;
- an accordance of hair color and color of eyes, which is specially agreed on for each breed;
- absence of any hairs of different color. Several hairs on the same part of body are considered to be a spot. One id unable to distinguish hairs, that lost their color as a result of ageing (going gray) or injury (white hairs may often grow on injured regions), from residual white spotting, especially on critical points of middle line of body, along the abdominal side body from the tip of nose to the tip of tail - point where residual spotting may be displayed. Spots of the tip of nose, edging of eyes and lips, and pads show the discrepancy of the viewed coloring and the coloring fixed in genotype. Though... dark spots on the mucous membrane or nose mirror in old animals are only the sigh of age processes.
Kittens and young animals, whose color of hair and eyes are so far not formed completely, go under cut requirements. But by the adult, "open" class the color change should finish. Though age is indicated in an evaluative blank, competition leaves no allowances.
Let's consider white coloring. The active gene is dominant white - W.
Solid colors in cats are those that are formed as a result of absence of aguthy gene (A-) and provide a monotone coloring of hair of a whole cat body.
White color stands apart and appears when the white dominant gene W is in due to which a cat puts on a white coat. But as white ray of light contains multicolored rainbow, white coloring (that is in fact the absolute absence of color) hides very different and unexpected combinations of genes that are suppressed by the white coloring gene, the strongest, the most dominant and very tricky gene. Due to this, latter thing the world of cats doesn't consist of white animals solely - nature created a powerful barrier to the overwhelming power of this gene: its lethality in a homozygous form WW-lethal.
Domestic cat doesn't live in Arctic or Antarctic, and its white fur doesn't serves as a camouflage while hunting among snow, besides there's no prays for a small domestic cat their. Wood and field mice spend winter deep under snow in cosy holes with full larders, and most birds that stay in forest for a winter are too tough for a cat. A cat is a poor snow walker, if outdoors then makes a stroll around the house and harries to go back: to a barn, a pantry or to a plate of milk. A white hair of cat has nothing in common with protective coloration of a polar owl or hare, or white bear. Its white color indicates a complete breakage with a wild past. An embryo development falls under profound changes due to a W gene activity. This gene blockades forming of melanin in hair follicles and affects structure of main glands (endocrine organs), that control all protective reactions in organism: from immunity development during infections (internal enemies) to the ability to defend external enemies and attack, if necessary. Protective systems in wild animals produce a stereotype of an active avoidance of human as a natural enemy. To escape, to run away, to hide - this is the law of contact with human for most predators as well. But it's inappropriate for domestic animals. Humans during centuries gradually approached those who managed to overcome, block fear and aggression inside. White cats are the last step of this possess. Many of them are deaf and are able to survive only owing to human care. White cats often occur to be really hysterical - can't stand another master, easily go into panic when in unknown place and may scratch its own master's hands. White cats when breed with white partners often have small litters, increased degree of mortality of kittens during first days of life, and inborn abnormalities - cleft palate, rupture -are also frequent. This is the lethal effect of W gene that prevents its universal expansion.
Eye color also falls under its expression. Blockage of pigment synthesis in retina provides some blue-eyed cats to have one eye of blue color and another - of some other, ordinary tone: yellow-brown, cupper-red, yellow, or green. This doesn't mean that cells in other eye doesn't have W gene, but it just hasn't displayed itself in the retina. Still the conditions, under which there's a 100% effect of W gene upon retina and acoustic nerve haven't been determined. Sometimes a funny situation happens: one half of eye is of ordinary tone, another is blue, or an ordinary colored retina has blue speckles.
The majority of blue-eyed cats are deaf. The majority, not everyone. Deaf cats will not live long leading a wild or relatively free way of life. They don't here their enemies and quickly become prays of stray dogs, craws, perish under wheels of cars. At home, beloved and well groomed, they can live long and happily, sometimes defended by their deafness from masters' quarrels. Deaf female cats often occur good mothers, perceiving kitten signals both by bone conductivity and other "the eighth sense".
Some specialists appeal to exclude white, blue-eyed deaf cats out of breeding and prohibit exhibiting them, as if there's any reliable way to define keenness of hearing in a cat not in laboratory but in short contact during exhibition examination.
Requirements to breed mate white cats with partners with other colorings destroy historically formed notion of some breeds: for instance, Turkish Angora has recently been recognized as an original breed by FIFe in that very white coloring. Moreover such requirements look far-fetched because many people love white cats, especially they appreciate blue-eyed ones. And as for Turkish Angora, it's a special style to have different color of eyes because, according to a legend, Turkish favorite national hero, the struggler for freedom Athaturk had different color of eyes. White cat is even allowed to enter mosques.
So, does the color of eyes in white cats reflect something and if only blue-eyed cats are deaf? Special studies of supervisors of Ankara zoo, that was described by Roy Robinson, a famous English cat-fancier, a curator of animal liberation society and professional geneticist refutes an everyday tale about deafness of white blue-eyed cats. This data shows that a number of deaf animals among white ones, that have colored or different eyes is almost the same, though is a bit greater in the case of blue-eyed cats. This is not that surprising. The gene is still the same as in yellow-eyed or those with different eyes, but the degree of its influence on the process of forming of a nerve cord and its derivatives in embryo, of cause is more considerable in animals in which this gene displays itself on the stage of development of sense organs: vision and hearing. In the case where it denotes itself affecting retina, it more often affects the organ of hearing.
What a color of retina depends on? Still no one knows if there any genes that only manage the forming of eye color. The color of retina first of all depends on allele of series B responsible for the degree of oxidation of black pigment melanin, chocolate B, or brown bl. Under their control retina gets brown, cupper-red, or yellow. In presence of aguthy A gene in cat genotype that controls for a "wild", or protective type of coloring, retina gets green or green-yellow color. But this is not obligatory. Solid-colored Oriental and Russian blue cats have green eyes if aguthy gene is absent too. Selection of sires that have the desirable for a given breed color of eyes, fixes this character in posterity. Therefore all white cats of different breeds are divided into following groups of white coloring: white with blue eyes - W 61, white with red, cupper or yellow eyes - w 62. Some white Persian cats, descended from Czech nurseries sometimes have eyes colored with brown as oversaturated w 62, white with different eyes - w 63, white with green eyes - w 64.
General formula for all these types of colorings may be the following: Aa/aa, B-, C-, D-/dd, I-/ii, S-/ss, T-OO/Oo/OY/oY, Ww.
White with cobalt-blue eyes, or foreign white - w 67: A-/aa, B-, CsCs, D-, ii, ss, T-, OO/Oo/OY/oY, Ww.
The number of white colored breeds is now dramatically reducing. Long time it has included Turkish Angora, colored kittens born from white parents were left with no pedigree and breeding. Specialists of GCCF were the first to recognize colored Angoras, while FIFe at that moment has merely accepted white Angora as an independent breed and the discrimination has started, especially among blue-eyed representatives of this breed because of fear of deafness. Though a well-known proverb "Less to hear - easier to fall asleep" is not out place here.
For a long time Foreign-whites considered to be a separate breed, both Siamese cats as shorthaired and white Balineses as semi-longhaired in which acromelanism is suppressed by a white dominant gene, from under which the Siamese coloring is manifested as a cobalt-blue color of eyes and which prevents influence of W gene on hearing and other systems.
White Orientals, as well as white Javaneses have green eyes but may carry acromelanism gene: ...Cc/Ccs... W-.
White recessive gene is a talk of the town. Specialists distinguish one more group of white cats with blue eyes, whose coloring is ostensibly formed under control of genes ca, W, c, logically completing the allele raw of albino series of gene C: C > cb > cs > ca > c. We should make a reservation, that real albino cats with red eyes as well as white rats, mice and rabbits haven't been detected. White cats of type caca have not also been found during selection. After all, they should be born and should have light-blue eyes. Try to come to your instructor and say about such litter, and he will immediately point out a white male cat in adjacent flat or an easily opened door to the next room where your second male cat, alas, white-colored lives. It has been surmised that this was the way by which Russian white cats from Russian blue were raised, but at closer examination, all known Russian whites have almost one white ancestor of unknown origin, but with W- gene.
Cats with white recessive coloring doesn't have their own code and until their existence hasn't been demonstrated for sure, let's consider this coloring to be most likely possible theoretically.
In contrast to most breeds of dogs, where in the presence of white coloring a tip of nose and edgings of eyes and lips must be colored black, in cats this is prohibited because colored or black spots manifest latent coloring which leads to a considerably smaller marks during exhibition. However this should not prevent a cat, perfect in all other respect as a bicolor carrier in pedigree breeding.
Kittens often have residual darkening on head without clear outlines that almost disappear while maturing. Fanciers highly appreciate such animals supposing them not being deaf for sure.
White cats amaze exhibition visitors by their clear, well-groomed snow-white coat, but only their masters know all the troubles to reach this effect. The most problematic in white cats are yellow spots on forehead, chin, naso-lachrymal furrow, base of first finger of fore paws, area around urethra and caudal gland. These spots form under exposure of "lachrymal stone", saliva, urine and adipocere from special small glands. They are removed with dissolvent that are the part of special shampoos for white cats.
The state of exhibition cage is very important for white cats. Rusty, badly painted cage will at once bring down to negative result all efforts of preparations of hair.
However, in spite of hard care, the number of admirers of white cats doesn't diminish.
Translated by Tatiana Karpova (Moscow)
(MSU, Biology faculture, Dep. zoology and ecology).