![]() ![]() Red males and tortie/calico/patched tabby females can be produced when only one parent has the red gene, but to produce a red female, you must cross a red male with a red/tortie/calico/patched tabby female. The reason red females are "uncommon" is that, statistically, the number of red males is equal to the number of tortoiseshell/calico, patched tabby, and red females. ![]() However, the generalization that "all calicos/torties are female" is true 99.999 percent of the time. While they are most commonly sterile, there *are* documented cases of fertile male calicos. Male calicos have genetic aberrations of various sorts, of which XXY is most common. This is also why male calicos are so rare: you have to have two X genes to be a calico. This is why you see more male red tabbies than females. A female cat who is homozygous for red (has it on both X genes) will be a red tabby. A female cat who carries one red and one non-red X will be a patched tabby, a tortoiseshell, or a calico (if she also has the dominant gene for white markings). ![]() Therefore, a male cat whose X carries red will be a red tabby. Red in cats is a sex-linked color, carried on the X gene. Having more white seems to encourage the formation of the big patches. The pattern of black/red or blue/cream can either be in big dramatic patches, brindling, or some of both. A blue-cream and white is generally referred to in the cat world as a dilute calico. This is the same gene that turns black cats 'blue' (grey), and red cats cream. A tortoiseshell that is homozygous for the recessive 'dilution' gene is referred to as a blue-cream, and that's what color it is: patches of soft grey and cream. A cat with patches of red and black is a tortoiseshell, or 'tortie'. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |