Please help settle an argument

[kap]

S/O says there are only female Calico; I say, tho' rare, there are male ones. What say you?




















Hey, I don't want to sleep in the dog house. It's 45 degree outside!

[RAMd®d]

...but discretion *is* the better part of valor.

Is this the hill you want to die on?






I didn't think so.

[Stephanie]

http://en.wikipedia.org/wiki/Calico_cat

[voodoopenguin]

If wiki isn't sufficient an answer then this might help as it explains how it's possible for there to be a male calico.

http://vetmedicine.about.com/od/catbreed...cocats.htm

[PeterB]

OK, guess what -- this is a fairly common question on one of my Genetics exams.



The answer is -- there are rare male calico cats. (You are right, and your girlfriend is wrong.) The traditional calico cat color (black and orange spots on a white background) comes from X chromosome inactivation ("Lyonization" ) -- which occurs in a random manner, such that-- in a female cat-- one X containing the orange color is inactivated, versus the other X containing the black color. Whichever X is NOT inactivated, that color appears. It is random as to which X gets inactivated, so you end up with a mosaic of cells. Males, having only one X chromosome, can therefore either have orange spots OR black spots on a white background, but not both. One exception to that is a cat with the equivalent of human Klinefelter's Syndrome, XXY -- this is a male cat but with an extra X chromosome.

More reading:

http://en.wikipedia.org/wiki/Tortoiseshell_cat#Genetics
http://en.wikipedia.org/wiki/Cat_coat_ge...ted_colors

Edit: drat, Stephanie and vp beat me to it...

[vicrock]

PeterB is correct - O (orange) in cats is sex linked and is found only on the X chromasome, unlike the genes for other colors. Traditional XXY cats which show both black and orange pigment in males are XXY and are sterile.

However you can also have a chimera which is the result of two ova that fuse early in development. These cats are usually fertile.

http://tortietom.nidoba.nl/tortiete.html

Shows a chimera male - who was fertile. Scroll down to Floid

[kap]

Ok. Thanks for the confirmation everyone! It means I am winning the disagreement, correct ... or am I?

[vicrock]

You are correct.

[OWC Jamie]

She's not wrong.
She's mostly right. (and hopefully half left)

[Don C]

Remember, that you may be right but that does NOT mean you won the argument.

Go ahead and declare victory if you must, but at the same time, be looking for an extension cord to run to the heater in the doghouse.