![]() Tyrosinase gene that is inactive at the cat’s core body temperature, leaving a The allele produces a temperature-sensitive Gene causes temperature-sensitive pigment expression. Most cat coat color traits show little influence from theįascinating exception to this rule. Population geneticists prefer to work with codominant genes? The dominance hierarchy at the albino locus is: C > c b = c s > c a > c. Produce white cats with either lightly pigmented ( c ac a) pale blue eyes or unpigmented ( cc) pink eyes. Rare albino alleles, c and c a, which when homozygous All three alleles ( C, c s, and c b) are dominant to the very With darker base body color and turquoise (aquamarine) eyes. (similar to the color of the “points” on the Siamese) and yielding green orĪnd yields a combination phenotype called “Tonkinese”: a Siamese-patterned coat Reduction in pigment production, reducing a black coat to very dark brown The homozygous c b c b genotype has a similar but smaller Light beige with dark brown “points” in the classic Siamese pattern. Production in the eyes produces bright blue eyes, while reducing pigmentĭensity in the hair shaft reduces the basic coat color from black/brown to a The homozygous genotype c sc s reduces pigment expression across most Both alleles are recessive to the full-color allele, C, but are codominant with each other. ![]() Two alleles at the albino locus, pointed, c s,Īnd sepia, c b, provide an example of codominance. Where the hetrozyogote resembles neither homozygote. the shorthairedĪllele, which completely masks the recessive longhaired allele) to codominant, Granules in the hair shaft, leaving large areas between the clumps containingĭominance is a continuous phenomenon, which runs the gamutįrom completely dominant (e.g. The dominant dense allele, D, producesĭense color, whereas the recessive dilute Has two alleles that affect the distribution of pigment granules in theįur. Heirarchy of these alleles is B > b > b l (Figure 2). Will find cats homozygous for these recessive alleles in Berkeley’s The light-brown allele, b l,įurther reduces melanin density to produce a medium brown coat, called Via importation of Siamese cats during the 1800’s. The dark-brown allele, b, reduces black to a dark brown,Ĭommon and occurs almost exclusively in pedigreed cats such as Siamese and This black color is evident in all-blackĬats, the black stripes of a tabby cat, and the dark ear-tips, feet and tails Three alleles that control the density of eumelanin granules in the hairĭominant and produces a black (actually super-dark brown) coat. Granules are thought to be elongated like footballs, and to reflect light in Granules are thought to be spherical in shape and absorb almost all light, There are two different kinds of melanin: Shape, size, and arrangement of these granules affect coat color. The colors in hair, skin, and eyes are caused by Such a mating is called a test cross (Table 1). Observing the phenotypes of its offspring from a mating with a longhairedĬat. It is possible to infer the genotype of a shorthaired cat by Dominant alleles are usually symbolized byĬapital letters and recessive alleles with lower case letters. Over-rides, or dominates the effect of the recessive longhaired allele. This is because the shorthaired allele, L, is dominant to the longhaired allele, l, which means that in a heterozygote It isn’t possible to determine the longhaired genotype of a shorthaired cat simply by This genotype is homozygous (both alleles are the same). The genotypeĪt a locus is a determined by the identities of those two alleles.įor example, the genotype of a longhaired cat at the longhaired locus, which controls fur Thus, each cat has two alleles of each gene one inherited from each parent. Indicating that it has a physical location on the chromosome. All the genes in all the chromosomes comprise Genes provide the information necessary to produce a cat. One member of each pair comes from Mom and First, we will consider the effects ofĬats have 19 pairs of chromosomes. ![]() Phenotype is a product of the interaction between genotype and environment. Important Concepts and Facts about Cat GeneticsĪspect of an organism that can be described or measured. However, the European wild cat ( Felis silvestris) may also haveĬontributed to the genetic composition of the domestic cat by hybridizing with The most likely wild African candidate for the ancestralĬat is the African wild cat ( Felis libyca). Generally believed that domestication occurred in Egypt Although there is not complete agreement on the origin of ![]()
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