Gene determinative of orange fur in cats (probably) found at last -- was difficult, as is in "Wrong" Place (catz!) [View all]

Last edited Wed Dec 4, 2024, 12:43 PM - Edit history (1)

It would be pretty easy to guess that Garfield was a tomcat even if you didn’t know his name—or didn’t want to peek under his tail. Most orange cats are boys, a quirk of feline genetics that also explains why almost all calicos and tortoiseshells are girls...

Scientists have long been fascinated by tortoiseshell and calico cats: the offspring of a black cat and an orange cat. Multicolored cats from such a cross are almost always female, suggesting the gene variant that makes fur orange or black is located on the X chromosome. The male offspring of such a cross are typically unicolor because they inherit just one parent’s X chromosome: We can guess, for instance, that Garfield’s mother is orange because he inherited his only X chromosome from her.

But female cats inherit an X chromosome from each parent. Cells don’t generally need both, so during embryonic development each cell randomly chooses one X to express genes from. The other chromosome rolls up into a mostly inert ball—a phenomenon called X inactivation. As a result, tortoiseshell cats end up with separate patches of black and orange fur depending on which chromosome was inactivated in that part of their skin. Calico cats add white fur into the mix because they have a second, unrelated genetic mechanism that shuts down pigment production in some cells...

But the gene encoding Mc1r [which is the determinate of red hair in other mammals] didn’t seem explain where cats’ orange fur came from. It isn’t located on the X chromosome in cats or any other species—and most orange cats don’t ave Mc1r mutations. “It’s been a genetic mystery, a conundrum,” says Greg Barsh, a geneticist at Stanford University...

https://www.science.org/content/article/gene-behind-orange-fur-cats-found-last



The Mystery Gene Was Hiding in Plain Sight, if one thought to look somewhere where other than where it was supposed to be.

Lesson in that about discovery and life.