Why are orange cats usually male while calicos, which have orange patches, generally female?

Question

If the orange color is sex regulated, how does it also appear on the females?

In: Biology

Answer 1

Very simple version, cat X can be orange or black. Boys are XY so they can be X(orange)Y or X(black)Y. Girls are XX so they can be X(orange)X(black) to make tortoiseshell or have the white masking gene too to make calico and normal males can’t have two Xs. They have to be XXY or chimera.

More male cats are orange just because of random selection, it takes two orange Xs to make an orange girl so if you have a calico girl and black boy you can get orange boys but no orange girls. Orange girls need an orange or calico mom and orange dad. Since lots of cats are just breeding randomly you get pairings that can’t make orange girls.