Article explains why ginger cats are generally male, calicos generally female.
Finally uncovered? I read about cat color genetics 30 years ago, at it was standard knowledge then that cats have either an orange or a black gene on each X chromosome. So in areas where the black gene is common, most of the orange cats are XY and all of the calico cats are XX.
What’s new in the link?
They’ve found the specific gene that causes it. They were expecting that a particular gene relating to colour was defective, but it’s actually a different gene located close to the colour gene that has an effect on the expression of the colour gene.
(My completely lay summary.)
For more information, I recommend Cats Are Not Peas: A Calico History of Genetics, by Laura Gould, which I read around ten or twelve years ago. Her interest in the subject was sparked by her calico male.
Thanks! That’s quite interesting.
Was he fertile? I’ve read that calico males are XX but phenotypically male, and as they are XX they don’t produce normal sperm. But maybe that’s not completely true.
I opened this thinking it was about humans.
One of the problems with putting emojis in thread titles. These things are all too often not clear.
Or XXY, or any of a number of other genetic abnormalities. Science never wants to fit into the neat little boxes humans like, and that’s especially so for biology.
I have a female orange tabby, and we’ve known she was genetically rare the whole time we have had her.
That’s a little different. The standard simple model predicts that calico males are impossible, and that orange females are uncommon. Even a single calico male proves that the simple model is incomplete, while a small number of orange females is entirely consistent with the model, as long as there aren’t too many of them.
And, in fact, if you have a region where there are more orange cats than black cats, the simple model would predict that many cats are orange, and a few are black males or calico females.
yes, of course. But most of those genetic abnormalities are rarely fertile. (not never, just rarely. As you say, biology is untidy.)
Don’t remember – too many years since I read it.
My sister-in-law has four orange tabbies – three male, one female.
They may also have XXY chromosomes, which in humans is called Klinefelter’s syndrome. Its incidence is unknown, because most men who have it don’t know it until and unless they undergo fertility testing; most of these men have very low sperm counts, or even none at all, and intact calico males are the same way.