Why do you hardly ever find a male calico cat or a female orange tabby cat?

Question

Male calico cats are rare and orange tabby female cats are too, why?

Answer 1

For a cat to be calico, it must simultaneously express both of the alleles, O (orange) and o (black), which are two versions of the same gene, located at the same location on the X chromosome. Males normally cannot do this: they can have only one allele, as they have only one X chromosome. Over 90% of tortoiseshell cats are females. Occasionally a male calico is born. These may have Klinefelter's syndrome, carrying an extra X chromosome, and will almost always be sterile or they may be a chimera resulting from the fusion of two differently coloured embryos.

The sex-linked orange gene, O, determines if there will be orange fur. This gene only appears on the X chromosome. In cats with orange fur, phaeomelanin (orange pigment) completely replaces eumelanin (black pigment).
For males, O results in orange fur, and o means that the O gene will determine the color (the black or brown color may be broken up into patterns if the cat has the agouti gene), so this would be epistatic to agouti locus.
For females, OO results in orange fur, oo means that the gene will determine the color (patterns if the cat has the agouti gene), and Oo results in a tortoiseshell cat, in which the B gene determines the color of the dark patches. A cat with Oo and white spotting genes will be a calico. The reason for the patchwork effect in female cats heterozygous for the O gene (Oo) is "X chromosome inactivation" - one or the other X chromosome in every cell in the embryo is randomly inactivated, and the gene in the other X chromosome is expressed (see barr body).
Rufous polygenes, as yet unidentified, that affect the richness of the orange gene's expression.

Answer 2

Sort of Here's the bests I understand/can explain it Calicos To have both orange AND black on the same cat requires two X Chromisomes. XX= Female. Males don't usually have two X's. That's why calicos (white, orange, black) are almost always females. Occasionally, there will be a "male" that is XXY. It will apparently be a male, and can be calico. THey are almost always sterile As for female orange tabbies, I had one as a child. She had kittens, too. Odds of an orange tabby female are very low though. Unlike male caliocs, they don't have to be genetic "mutants" BUT the odds are stacked against them. For example, they would HAVE to have a mother and father both with orange. For example, a calico mated with an orange tabby male could potentially have female orange tabby kittens. From what I understand. Hope that answers your questions. Thumbs down to the person who said "A few rare cases have been reported in which sterile, deformed, or sickly kittens have been born as female oranges or male calicos, but they often die young and cannot reproduce." That is NOT true of female oranges. As I said, THEY are not a genetic mutation, they just beat "the odds" of having the exact right combination of parents and genes. (kinda like the odds of two brown eyed parents having a blue-eyed child). It's somewhat true of calico males. At least being sterile. I don't know about sickly. Again, they are a genetic mutation (XXY instead of XY)

Answer 3

"Gillian"'s answer is awesome! Male calicos are 1 in a million, and orange females really aren't rare anymore. Who knows, maybe male calicos won't be rare in a few more years!

There is nothing rare about male white cats.

Answer 4

You actually will never find a male calico. it is a gene that only occurs in the female felines. As far as I know there arehave been few studies but the results are the same. There are very few orange females - this is true. It is not a specific gene like the calico, but there are more powerful dominant genes such as the tortishell or the american black shorthair that dominate in litters.

Answer 5

The color traits needed for the calico coloring are carried, seperately on the X chromosomes. So while a female can get orange on one X and black on the other, a male, who only gets on X chromosome, can *generally* only get black or orange, not both.

Answer 6

What an excellent question! I never thought about why orange cats are always male!

Answer 7

Gillian is right - and there is actually research into the idea that the same chromosome when expressed in humans is related to down's syndrome - but it's a mystery why that effects men and women equally.

Answer 8

I've also heard that it is very rare for a all white cat to be male ? Stange how nature works isn't it !

Answer 9

Genetics.

Answer 10

both are sex linked traits!