Mary Allen
In the second part of the theory of colors, we devote ourselves to white, black, and red. The albino series leads from the wild color through several stages to the pure white rabbit. The black spread factor fixes yellow or black and sometimes can’t decide
There are several varieties of white rabbits: in addition to whites with blue eyes, which we will discuss later, there are whites with red eyes and whites with dark eyes. These two go back to a mutation of the color gene A, which contains the building instructions for the pigment-forming enzyme tyrosinase. Due to the mutation to a pigment cells are present, but the enzyme required for pigment formation is missing: the rabbit is an albino, often abbreviated to RA (roach). Since no other color gene comes into play without pigments, the gene formula for albinos is given as a—–. While albinos cannot show color, they do bring color when crossed with a non-albino.
If the enzyme tyrosinase is partially active due to the mutation to a result is a Russian-colored rabbit, a white animal with red eyes, but with dark markings on the nose, ears, legs, and flower (tail). Sometimes the English name Himalayan is used for this coloring.
Russian rabbits are born white, the markings only develop gradually. They are more intensely colored in winter and lighter in summer. It is a cold blackening, which means that the marks appear where the skin temperature falls below a certain threshold. This can be shown well by shearing a spot into the white coat. Dark hair grows back on the now cooler skin. The markings are black (anBCDg), blue (and), Havana (anBcDg), or mauve (anBcdg), depending on the genetic make-up, whereby only Russians or Californians with black markings are recognized here.
The marten am is also a partial albino. An animal with am and wild color factor G resembles a chinchilla. The type marten is only obtained in the non-wildly colored and cleaved form amanBCDg. The blue marten, which is bred to match the color of the Rex rabbit, also carries the information for blue in the gene formula: amanBCdg. In Siamese rabbits, sometimes called yellow martens, the marten gene is combined with the gene for yellow, so their gene formula is amanbCDg.
How Thuringian Sallander Becomes
The chinchilla gene achi is another variant of the albino line, turning colored furs into their respective black and white versions. In this mutation, the color-forming enzyme tyrosinase can form the dark eumelanin, but not the reddish phaeomelanin. The wild color becomes the chinchilla with black and white banded hair (achiBCDG). Combined breeding creates a whole range of exciting colors: the tan rabbit becomes the white-awned rabbit (Chicago), the Thuringian becomes a Sallander (aching), the yellow rabbit becomes a white rabbit with dark eyes (achibCDG). If the yellow initial animal had black awn tips, these become veil-like soot on the dark-eyed white rabbit: This is how the black-awned rabbit breed came about. In addition to the normal chinchilla gene achi, there is another variant that is referred to as the dark chinchilla. However, no breed is recognized in this color.
The so-called black spread factor B/b brings reddish-yellow coat colors into the color wheel. With AbCDG, a yellow rabbit is created with the characteristic wild color markings of a light belly, light circles under the eyes, and a border around the nose and jawbones. In the non-wild colored version AbCDg, you get the popular Madagascar color.
Mutation b affects the “switch” that switches back and forth between the formation of dark eumelanin and reddish phaeomelanin, as is necessary for wild-colored hair with its black-reddish bands. With the mutation to b, the switch stays on phaeomelanin, so to speak. Nevertheless, the formation of eumelanin is still possible in some cases, as shown by the dark tips of the hair, which are undesirable in yellow-colored animals.
Modeled on a Birch Trunk
This is even clearer in the case of Madagascar-colored rabbits, whose dark mask on the head and the sooty veil on the sides of the body and abdomen show that they can partially form eumelanin. The Madagascar color is also dependent on the cold to a certain extent and also darkens as the animal ages.
The black spread factor is not only available as B and b but in several mutation variants. Iron gray BE is dominant over the wild form B. With iron-gray the switch “sticks” so to speak on the other side than with b: Dark eumelanin is formed almost exclusively, which partially covers the wild color G. Homozygous iron-grey BEBEs are practically black, only in the split-breed form BeB does the rabbit show the blackish color with brown speckles. The attractive color is referred to as “golden steel” in the English-speaking world and is distinguished from “silver steel” with white speckles. This variant is obtained by introducing the chinchilla gene.
The mosaic factor bj leads to the Japanese AbjCDg, in which the two pigments are divided into black and reddish color fields. The Rhön rabbit combines the mosaic factor and the chinchilla gene; It has the same genetic formula as the magpie rabbit (achibjCDg), but it is selected for a finer pattern because the color of a birch trunk is the model for the Rhön. Finally, the mosaic factor forms the basis for the three-color check.