Whether you call them red, marmalade, or orange, these sunshine cats will go a long way in brightening and lightening your home and your life. It is a theory that if a hybrid is bred in the other direction, (in the case of the Savannah, breeding a female serval to a male domestic or male Savannah) there would be a higher incidence of female sterility and male viability. They are silver and the non-agouti cats will have a black coat with a white ground color and oddly enough the spotting pattern remains visible in that white undercoat. The agouti signaling protein interacts with the melanocortin 1 receptor to switch between black and red pigments, creating a banding pattern in individual hairs. Because there are these different possible combinations, females have less of a chance of being only red than males do. This Genetics article is not meant to be a genetics book or a complete guide to the genetics of the Savannah cat. Dominance Theory is one that may affect Savannah breedings in that the incompatibilities may come from cellular information for fertility may be at different loci (see locus above) and therefore not translated correctly resulting in infertility. Consider this then the female can only pass on an X and the male can pass either an X or a Y. Black chausies with silver tipped fur occur and this is belived to be a form of agouti rather than smoke shaded or chinchilla locus a aa solid aa cat. Offspring can be agouti or non-agouti depending on the genetics of the mating. The areas outside of the dark tabby stripes are composed of agouti-banded hairs. These allow you to take a mouth swab of your cat. In rabbits, the wildtype is agouti with a light belly, and a recessive non-agouti allele causes a black coat. Genotype is the internal coded and inheritable information; the veritable blueprint or building blocks of the cat. This mutation has an autosomal recessive mode of inheritance, thus when two copies are present, pigment switching is prevented from occurring. This results in individual banded hairs with the visual effect of an intermediate color between the two pigments. What does this mean? Heterozygous for agouti. aa = The cat has two copies of the non-agouti gene (solid). Hairs in the darker stripes do not undergo the shift between black and red-yellow pigment production during their growth, and thus remain uniformly dark. Meiotic drive is of special interest to those Savannah breeders who work with the filial generations and is one school of thought as to why we have sterile males at those generations. When the cat is homozygous (genotype aa), it will result in black pigment production throughout the growth cycle of the hair. If both parents are spotted and carry for the classic (marbled) pattern and they both happen to pass on this recessive pattern, the two spotted parents can have a homozygous classic patterned kitten. Black Coronet by Becky Lanahan, used with permission Molecular genetics and evolution of melanism in the cat family. Sex in mammals, including humans, is determined by the two sex chromosomes; the X and the Y chromosome. Locus is the exact number location/position on the chain of 38 chromosomes, such as number 14 or number 3. Orange acts by changing black pigment to red and is epistatic (overwrites) to self (non-agouti) in cats. Repeating the breeding a few more times and only spotted kittens occur and we then know positively the spotted parent is homozygous for spotting because it takes two classic genes to make a classic pattern and the homozygous cat cannot pass on classic. The dominant allele, A , produces banded furs which help to create the tabby pattern. The Agouti gene is responsible for determining whether a mammal's coat is banded (agouti) or of a solid color (non-agouti). Currently, there are other theories based on the Rule such as meiotic drive above and others covered briefly below. The Agouti gene is responsible for determining whether a mammal's coat is banded (agouti) or of a solid color (non-agouti). In cats, the dominant form of the Agouti gene causes the tabby pattern, while the recessive form allows non-tabby coats. The agouti gene determines whether a cat has a tabby pattern or not, but the non-agouti gene doesn't work when the red pigment is expressed. Female Offspring Polygenetic traits (also called quantitative traits) rely upon multiple genes linking together to exhibit phenotype. Non-agouti does carry one of the tabby alleles and is seen as ghost spotting in a young cat/kitten. Offspring will be determined by the Agouti gene status of the mating partner. A third allele, possibly a mutation to a regulator or promoter region, is thought to cause black and tan color.