US scientists discover gene behind orange cat color, unique among mammals

Scientists at Stanford Medicine have identified the genetic mutation responsible for orange coat color in domestic cats, a trait unique among mammals. The mutation occurs on the X chromosome, explaining why male cats are more likely to be fully orange than females. This sex-linked orange gene causes increased activity of the Arhgap36 gene in pigment cells, where it's not normally expressed. The discovery provides insights into molecular evolution and how genetic changes lead to new traits in animals.