Breeds of domestic cats, and especially care for them
Genetics colors of cats
If you are interested in obtaining the genetic bases of various colors, as well as those which are theoretically possible colors - This article is for you.
Colors cats are different variety of patterns and colors. Names that represent these colors are often based on genetic theory. Many people are confused when confronted with the names of colors bytuyuschimi among cat lovers. This article will help you understand these terms and their causes, but does not attempt to describe the mechanisms of inheritance and does not give the formulas for calculating the possible result of interbreeding of different colors.
1. Pigmentationcolor hair, skin and eyes depends on the presence of the melanin. Melanin is the body hair in the form of microscopic granules, which differ in shape, size and quantity, which causes differences in color.
There are two types of chemical melanin: eumelanin and phaeomelanin. Granules Eumelanin spherical and absorb almost all light, giving black pigmentation. Granules Phaeomelanin oblong (elliptical shape), and reflect light in the red-yellow-orange range.
Some genes can alter the density of melanin granules in such a way that we obtain different colors. The largest differences are observed in the dark (based on the eumelanin) colors.
With fewer pellets in the body of eumelanin hair black varies over chocolate (or brown) to the color of cinnamon. Chocolate is recessive relative to the black and cinnamon - about chocolate. Such mutations causing allele (B)
Mutations in the genes of a dark lead to the appearance of blue, lilac and fawn colors (fawn). This is due to grouping of pigment particles in the body hair. Blue - is a diluted black, it is a different shade of gray. Purple - diluted chocolate, it is sometimes compared with the color of frost, or lavender. Fawn (baby deer) - diluted cinnamon color - the color of coffee with milk or caramel. Such mutations are dependent on the location of alleles (D). Dilution recessive relatively saturated colors.
Red-key (phaeomelanistic) color are significantly less variation. The red color is usually described as orange or marmalade, and a Russian - red. Some cats are so pale pigmentation, which may be called yellow. Cream - a diluted red, the color of cream. For the red gene symbol is used (O). The black color is recessive to red.
red gene (O) associated with the X chromosome, so it depends on gender. Cats one X chromosome, so if the cat carries the red gene, it will be red. Cats have two X chromosomes, so the cat will be red if both X chromosomes carry the red gene. However, many cats red gene is only one chromosome, which leads to the appearance of black pigmentation in patches (patches). This combination of red and black tortoiseshell called (Tortoiseshell).
A typical tortoiseshell - a randomly placed spots of black and red. Some more red, some black.
Depending on the saturation, the spots can be black and orange and blue-cream (usually these are not called tortoiseshell, and just say - blue-cream). Variations of the black lead to the appearance of chocolate turtle (Chocolate Tortie) and koritsecherepahovyh (Cinnamon Tortie), and their variants are called dilute tortoiseshell lilovokremovymi (Lilac-Cream Tortie) and Olenenkokremovymi tortoise (Fawn-Cream Tortie).described mutations exist in Europe and the Western Hemisphere, and for hundreds of years. Another set of mutations was introduced from Asia, and introduced and Siamese cats Burmezskimi. Burmezy carry genes for color Sepia (Sepia) (cb), and Siamese - genes colored spot Point (Pointed) (cs). Such mutations vyzavet allele (C), their combination (cb / cs), as a tonkiyskoy cats, mink coat is (mink, mink).
The table does not show two color mutations albino, which typically have a one-color white hair, regardless of pigmentation genes. It is white with blue eyes (ca / ca), and white with pink eyes (c / c).
2. White colorThe color white - it's the absence of any pigmentation. Solid white coat may be obtained in three completely different cases:
1. White albino.It is a recessive variant, described in the previous section
2. Solid white spotsFactor white spots (S) is dominated by not fully affected by polygenetic modifications and usually leads to the fact that the cat is painted in white, not all. However, the spots can be placed so tightly that the animal is completely white. White spots are described in the following sections.
3. The dominant whiteThis mutation suppresses all other genes of pigmentation, and gives rise to white coat color and blue eyes. As the name implies, this is - the effect of the dominant white gene (W).
In the dominant white genes in other colors and patterns, and although there are, but they are completely hidden. The only way to determine the primary genotype - cross with colored cats are well-known genotype.
Hybridization of the two dominant whites usually leads to a completely white kittens, but if both parents - are heterozygous (W / w), then some of the main colors of the kittens may appear. If the genotype of white parents do not know the pedigree of the test or mating - mating outcome is unpredictable.
The dominant white is found in different species. Sometimes white Oriental Oriental cats are seen by some associations as a separate breed. In the dominant white color blue eye color is much deeper than the albino, and it is considered a virtue. Best blue eyes completely white mark in the Eastern Oriental cats carrying a gene repressed chocolate color.
Deafness in cats is associated with the genes of spots (S), and with the dominant white (W), but not an albino gene (c / c or ca / ��ca).
3. Ticking and TabbyThe preceding paragraphs describe the solid colors. However, these colors are not the most common. Many cats are ticked and ticked most of them the color that is different from the main drawing, called tabby.
ticking - the result of gene expression agouti (agouti) - denoted by (A), which leads to the appearance of hair on each strip light and dark pigmentation. Agouti gene allows full pigmentation of hair to start growing, then slows down the synthesis of pigment for a while, and then resolves. When hair reaches its full length and stops growing, the pigment synthesis stops. As a result, her hair tightly painted on the tip, then goes to a strip of yellow or orange, then again a densely pigmented area, coming down to the yellow or orange hair root.
agouti band found in black-and-key (eumelanistic), and red-and-key colors. In both cases, the band corresponds to the period of slowing production of melanin. Agouti band in black-and-key colors and causes eumelanin (no phaeomelanin), but the pigment granules are sparse and small islands, which gives a yellow or orange. Thus, agouti - a mixture of sites with no eumelanin and phaeomelanin pigmentation.
In the eumelanin-pigmented hairs, the band agouti usually yellowish shades. However, their color may be orange - a color is caused by a factor of red color. This polygenetic factor, while not isolated and is not identified, but breeders are able to select those animals that give warm color tabby. In particular, the brown tabby (Brown Tabby) - a genetically black, but the selection of individuals with a strong factor in red managed to get a rich brown color in the ticked hairs.
The mutation is responsible for solid colors is called non-agouti (non-agouti) (a / a), and is recessive. The effect of non-agouti inhibits ticked so that the pigment is evenly distributed throughout the length of hair, except the root, where usually ticked to some extent preserved.
In the tabby gene is responsible (T), which causes the stripes and spots on the primary color tikkiovannoy wool. Well-known types of tabby are given such descriptive names:
1. Mackerel tabby (Mackerel Tabby).ticked hair bands located on the main color (like a tiger). This is the most common tabby pattern.
2. Classic Tabby (Classic Tabby).are ticked hair patches, often in the form of a "bulls eye" on each side, or "butterflies" on the back. This figure is also called tabby spotted (Blotched Tabby).
3. Ticked tabby (Ticked Tabby).ticked hair evenly distributed throughout the body, the hair looks like a freckled. This figure is also called Agouti (Agouti Tabby), Abyssinian (Abyssinian Tabby) or wild.
4. Spotted tabby (Ticked Tabby).ticked hairs interspersed with spots or rosettes of primary color (like a leopard or jaguar).
classic tabby (tb) is recessive relative to Tiger (T), relative to the Abyssinian tabby recessive (Ta).
Genes agouti and tabby also be combined with all the colors of albino series - sepia, mink and colorpoint. Americans recognize Burmezskuyu Tonkiyskuyu and breed only black-and-c main non-agouti (eumelanistic non-agouti) coat color, not recognizing the manifestations of tabby. In Singapore (Singapura) is recognized only "sable agouti" (Sable Agouti Tabby) color - ticked tabby wax (seal sepia ticked tabby). Some associations allow Tabby Siamese cats (Siamese) - their color is called linkspoynt (Lynx Point) - a lynx spot.
Note that there is no solid red and cream colors. Although breeders are red and cream cats, looking uniformly colored, selecting for breeding the red gene carriers with a tendency to reduce the contrast of the figure, the letter "M" on his forehead, still present even in the most plain red-and-key (Phaeomelanistic) colors. [ / bbp]
ticked tabby with regard to the Abyssinian and Somali (Abyssinians, Somalis) give special names:
Sorrel Abyssinian sometimes called red, but it is - wrong. All these colors - black and basic. Red and Cream (Red, Cream) Somali and Abyssinian colors not recognized by the U.S. associations.
Note that the spotted tabby (spotted tabby) is not allocated as a separate genotype. Finally, it is not clear whether the spotted tabby tabby gene mutation, or is it simply the effect of modifications polygenetic tiger tabby (mackerel tabby). Some breeders suggest the existence of the spotted tabby in different species of wild cats, as confirmation that the spotted tabby independent mutation. In practice, however, spotted tabby gives progeny with pictures of spotted, to brindle, and breeders have continually selected producers to clear spots, otherwise the picture goes to the offspring of a tiger.
Tortoiseshell cats can also have tabby pattern. In tortoiseshell tabby (torbie), tabby pattern manifests itself in red, and black areas. The solid and ticked the band in the red areas, without interruption, switch to black areas.
4. ShadedIn an ordinary tabby, ticked hairs have light stripes, but they are not devoid of color. Typically, light yellowish stripes, but sometimes it can look orange.
Less color primary color stripes give agouti. Zatushevannost (Shading) extends the agouti band so that light areas can reach the hair root. This effect leads to the fact that the hair is dyed the tip, the color of which determines the basic color gene, and the hair is much lighter. If the bright part of the hair white tones - this is Silver (Silver, Silver), if the yellow or cream - gold (Golden).
There are several explanations of genetics shaded colors. Previously believed that gene chinchilla (Ch) (Chinchilla) - a modification of the gene albino. If this were so, it would have been impossible colors such as shaded sepia, mink and colorpoint. Experiments breeders deny this theory. Later, it was thought that zatushevannost is a separate gene, called gene inhibitor (I). But this theory could not explain all the varieties of shaded colors and success in getting their breeders. So, now believe that zatushevannost to have at least two genes, however, tentatively, this theory has also not been proved.
All these theories attempt to explain the genetic factors that inhibit the synthesis of pigment after reaching a certain length of hair. The combination of zatushevannosti with agouti and tabby gives rise to such color as the chinchilla (Chinchilla), shaded silver (Shaded Silver), Silver Tabby (Silver Tabby) and Smoke (Smoke).
In a chinchilla (Chinchilla), each hair is colored by the end of the well and pale to the root, so all the hair seems slabookrashennymi and the effect of tabby markings are not there. Tipping is so weak that even the color seems at first sight with white, but on closer examination, like sparkles.
In the shaded Silver (Shaded Silver), all the hair is dyed to the point where the band usually starts agouti. As well as monochrome and Chinchilla ticked areas are painted in pale the point where the where the band usually agouti, so drawing is not visible. However, in the shaded Silver colored tips are long enough so that the main color is clearly visible, especially on the head and back.
have silver tabby (Silver Tabby) tikkirovanye brightly colored hair and pale at the tip to the root, but have normal-colored hair the color saturation. The tabby pattern is enhanced by the contrast between almost white hair and patches of ticked basic color.
Smoke (Smoke) picture - the result of glossing over the continuous non-agouti coat color. All good hair dyed to the point where there was a band agouti, and then move to off-white undercoat. This looks like the main color, but if you blow into the coat, visible and contrasting white undercoat. It is also clearly visible in the movement of the animal.
Similar figures can be shaded and a golden undercoat. They are called golden chinchilla (Golden Chinchilla), Shaded Golden (Shaded Golden), Golden Tabby (Golden Tabby) and Smoky Gold (Golden Smoke). The difference from the white (silver), shaded, these animals warm undercoat of cream or apricot.
The most impressive black-and-key (eumelanistic) shaded colors, because they are more contrasty, but the red and cream colors are also very beautiful. The red-shaded main colors are often called "Cameo", they meet the usual name is given below:
Since zatushevannost combined with black-and-key, and a red main color, it can also occur in all tortoiseshell.
Theoretically, a golden undercoat is available in red and the main color, but breeders have so far such a combination are not worthwhile. The lack of contrast in the shaded Red Gold makes the effect is almost imperceptible, but the black spots Turtle Zolotistyi shaded tortoiseshell or golden Chinchillas it is quite possible to observe.
5. With white spotsvery common mutation that leads to the appearance of white spots. Color of spots sometimes referred to as "motley" (pinto, piebald). Spots are many varieties - from white sneakers, white feet, white-nose or chin. From small white areas, to the almost complete absence of sites with the main color.
White spots can be considered as a mask on the main color. Usually, the owners of cats that have survived the dark stripes only on the head and tail, consider their pets white. This is not right - in fact it is a cat with tabby markings, which is hidden under the white spots.
white spots occur in any color on any of the above figures. Commonly known as such colors, indicating the primary color, and adding, "With the white." For example, red mackerel tabby (Red Mackerel Tabby) with white spots is red mackerel tabby with white (Red Mackerel Tabby and White), and purple is purple and white.
Tortoiseshell with white (Tortoiseshell and White) has a special name - Calico (Calico, Chintz). Therefore, Blue-cream & white is sometimes referred to dilute Calico.
Factor white spot (S) - the dominant mutation. Homozygous cats (S / S) usually have more white area than the heterozygotes (S / s), but other genes may modify the degree of manifestation of white spots. Sometimes the spots may increase with age.
Factor White spots can give rise to a blue-eyed cats and cats with different colored eyes, if the spot covers one eye. This gene is associated with deafness, especially if white spots reach the ears. If the white patch covers the eyes and ears, then maybe that will turn a deaf cat with blue eyes. Deafness may affect one or both ears. This is caused by degeneration of the shell of the inner ear, which begins in the first days of life. Such deafness is incurable.
noticed that the white spot may be present on the cat white color! Of course, a spot on a white visually indistinguishable.
6. Explanation of notation in the article .
0 comments:
Post a Comment