More Recent Comments

Monday, January 18, 2010

Epigenetics and the Calico Cat

This is our friendly calico cat. She lives on the farm where we are staying. Almost all calico cats are female—do you know why? It has something to do with epigenetics.

See: Calico Cats—it's one of my most popular postings.

Can anyone explain how some very rare calico cats might be male?


[Photo by Ms. Sandwalk]

6 comments :

Anonymous said...

XXY cat? Does that count as male in cats? It does in humans.

Unknown said...

could be chimeric

RaulFelix said...

Maybe a dispermic embryo, giving rise to an XX/XY chimera.

TwoYaks said...

If x-inactivation is now considered "epigenetic," the term has become so wish-washy and overly broad that it has ceased to have any meaning. I can understand some variation in terminology, but this is reaching absurd heights.

Larry Moran said...

TwoYaks says,

If x-inactivation is now considered "epigenetic," the term has become so wish-washy and overly broad that it has ceased to have any meaning.

I agree.
 

Ralf Muschall said...

If this happens as early as in the 20-cell-stage, the ovaries should have essentially all the same X active. Do the Barr bodies get unpacked completely during meiosis, or is there a correlation between the Xs of the offspring?