And speaking of calico…
Been meaning to look up why calico cats are always female. Here’s the skinny: calicos are usually white, orange and black (or tabby or gray or…whatevs). About 70% white on average – that has nothing to do with the topic at hand, but I thought it was interesting.
The X chromosome carries the gene for either ginger or black (or a variety of non-white colors). One color per X chromosome. So only XX (that is, female) beasts can have both ginger and black.
Except those poor little bastards with Klinefelter syndrome. They have XXY, XXXY or even XXXXY chromosomes. I don’t think it creates much of a problem in cats, but it can produce the occasional a male calico.
The gene for white isn’t on a sex chromosome, but elsewhere in the genome, so any old cat can carry it.
“But wait, Stoaty, you magnificent beast!” I hear you say, “most gingers are male. How that be?”
Male gingers carry the ginger gene on their one X chromosome. Female gingers have to have the ginger gene on both X chromosomes. That makes the ratio is about 3 to 1 male to female, and I believe ginger girls must have ginger daddies.
I think ginger and black without the white is how you get a tortie, but I’ve about come to the end of my genetic education.
If you ever yearn to feel stupid and slow, try looking into the genetics of chicken colors. Here’s a look at the basics.
January 27, 2021 — 7:38 pm
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