are all calico cats female ?

[plowerydope]

i've heard that all calico cats are female.
the small sampling of felines i know/have known
holds to this, but i was wondering if it's true.

thanks!

patrick

[light strand]

Yes they are. Apparently calico color is a sex-linked genetic trait. Here is a really good explanation.

[light strand]

Damn, I should have read the ENTIRE article myself

The story is different for male cats. Males have only one X chromosome, and it is never inactivated. Whatever color gene is present on this X chromosome will determine the color of the cat. Males can be calico or tortoiseshell only if they are born with 2 X-chromosomes and a Y (XXY), allowing one X to be inactivated. This genetic defect (XXY) is very rare.

So the answer should be.....male calicos are very rare, but they do exist.

[TV time]

Not quite true. The huge percentage of calico cats are indeed female. However, there are a very, very few that are male. Which makes them, very, very valuable.

[sunstone]

The genes for orange and black coat color are carried on the X chromsome. All normal females are XX. Therefore, a queen could have the gene for black on each of her two X chromosomes (and be black) or she could have the gene for orange on each of her two X chromosomes (and be orange) OR she could have a gene for black on one X chromosome, and a gene for orange on the other X chromosome (and be orange and black...known as calico)

Since normal male cats are XY, and the genes for orange and black are not found on the Y chromosome, male cats can have a black gene on the X chromosome and be black, or they can have an orange gene on the X chromosome and be orange.

Any male calico (black and orange) cat would have to have the genetype XXY...that is an extra X chromosome, so the cat would be sterile. Very very sterile, and not useful for breeding.

As an aside, in some parts of the US, what are known as calico cats are black, orange, and white. The white is caused by an unrelated gene on genes other than the X or Y...and it causes the hair to be white, regardless of what gene is present. You can see the effect of the gene on cats...with low penetrance, there is a small white patch on the throat and/or chest. With more penetrance, the white is found in other parts of the body. Horses and dogs have similar genes that cause white areas on the body.

[Netbrian]

TV Time: You got the explanation generally correct, but from the different books on cats I've read, I've gathered that while male calico cats, while very rare, aren't really valuable. Of course, they'd often be valuable to the owners, but then again, wouldn't any cat?

[happyheathen]

Calicos and tortoiseshell (torties) are tri-color.

Cats carry their color genens on the X chromosone.

Each X can contian a max of 2 colors.

ergo, to get 3 colors, one either needs:

two X's (female)

some really wierd genetic structure.

In the early 70's (when I was breeding cats) there had been a total of 6 known fertile tricolor males (none of whom "threw" tricolor sons)

[Rushgeekgirl]

While I have nothing significant to share...
I took in a female pregnant calico. She had three calico female kits, one black female with a tiny white belly patch, and two orange and white striped males.

Anybody want a kitten?