This is seriously one of the coolest things ever.
So recently I learned that a cat’s coat colouring is linked the the X chromosome. I also learned that only one of each sex chromosome can be “active” or allowed to replicate at a time. Boys have it easy since there’s an X and a Y so they both can be active simultaneously but girls have 2 X’s so the mom’s and the dad’s X duke it out for the first 4 days from conception until one “wins” and becomes deactivated.
Great, I thought I was going to be learning cool cat facts to show off to people so that they think I’m ultra cool not sitting through grade 11 biology all over again you might be thinking well don’t worry we’re getting there hold your horses and also it’s just one cat fact cause I didn’t want to overwhelm you. //if enough people want it we can do cat facts in which there are multiple, quick facts about cats that are just as cool//
So during those first 4 days, both X’s are duplicating like no one’s business and once one of them shuts down no new ones are created but the old ones are still kicking around. These old ones get spread around the body and intermingled with the other cells which is normally not visible obviously BUT in cats where it’s linked to their colouring you can actually see it!! Calico cats! The reason they have this type of fur pattern is the X chromosomes from the mom and the dad distributed around their body!!
Also the reason why calico cats are solely female; males don’t have it in ’em. (literally speaking)
See, I told you this was cool.