The Ticked gene inherited its symbol, Ta, from its symbol on the hypothesized Tabby gene. It is possible that a cat being homozygous vs heterozygous for mackerel (McMc vs Mcmc) could have some effect. This is because classic is the fundamental underlying pattern that is being erased from. However, spotted tabbies may still appear to have their spots in a whorl shape. If the cat is mcmc, the protein needed for the erasing is not being produced, so the polygenes cannot work to have it erase more or differently. We also now know that spotted can only modify mackerel tabby, probably because it uses that same “erasing” function as for mackerel. I represent this in my calculators by using spsp for mackerel, Spsp for broken mackerel, and SpSp for fully spotted, however, there are degrees in between these as well. What this tells us is that unlike in the traditional model, where two fully spotted cats can carry non-spotted, under this model it is extremely unlikely for two fully spotted cats to have a mackerel kitten. This model can still be useful, but it has since been shown that there is a spectrum between spotted and mackerel, the intermediate of which is broken mackerel, and it appears to be determined polygenically. Spotted tabby has been traditionally identified as a dominant trait on a single gene, with the symbol Sp. The Mackerel gene appears to have a function in “erasing” the base pattern, leaving behind vertical stripes rather than the blotchy classic pattern. In truth, the “base pattern” of all cats is classic, which can then be modified in various ways. The Mc locus, sometimes just known as the Tabby gene, determines whether the cat’s “base pattern” will be mackerel or classic. The hair shaft image above reflects the current data I have, and I intend to write a more in-depth article about the interaction between red pigment and agouti eventually. It causes the charcoal pattern in Bengals - in its homozygous form, it produces twilight charcoal, and when combined with nonagouti it produces midnight charcoal.Īs mentioned on the Sex-linked Red page, red pigment does not tend to play nice with the Agouti gene. It is denoted Apb, for the scientific name of the Asian leopard cat, Prionailurus bengalensis. We also know of one additional form of agouti, found in hybrids derived from the Asian leopard cat. Animals with extreme nonagouti have very sleek, glossy coats due to the effect of melanin on the structural integrity of the hair. There is no banding or paler root whatsoever, and the hair is completely pigmented. This form of agouti is found in some rodents, notably mice and guinea pigs, and is a complete and true nonfunctional agouti. It is also possible that there could be a yet-to-be-identified “extreme” nonagouti. This same fading is present in the stripes of the tabbies. In all the pictures that I have received, there is some degree of fading toward the base, which can vary in intensity and may be more brown or more gray in tone. There may be some faint banding, which can result in “ghost markings”, but the hair remains overall fully pigmented. It is recessive to the functional allele (A), which allows the tabby pattern to show. The allele for solid (a) is a nonfunctional version of Agouti. This makes the background color look generally lighter and more reddish or golden in tone compared to the stripes, which are more fully pigmented. There is a dark band of the base, then there is a band of golden taking up half or so of the hair shaft, and the tip of the hair has multiple shorter bands of black and red pigment. The hairs of a standard tabby cat look something like this. In a tabby cat, the background color is created by these signals turning on and off, resulting in a hair with alternating bands of black and red pigment. It does this by affecting whether black pigment or red pigment is made. ![]() The A locus, Agouti, is responsible for determining patterning in many different mammals. I am currently only collecting them for illustration reference and will not be sharing them or putting them on the site, if I ever do wish to do so I will ask. If you would like to help further my research, you can submit images to my email. The hair shaft illustrations on this page are all referenced from images submitted to me. There are three identified genes which have a clear effect on tabby markings, plus some other theorized genes and polygenes. This has now been disproven for some time. The old theory was that all tabby patterns were mutations on one Tabby gene, following a strict dominance hierarchy. ![]() There are many different varieties of tabby pattern. A tabby cat is a cat with a dark striped or spotted pattern on a paler background.
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