Dilute calico cats owe their coloration to a fascinating genetic interaction. Like all calicos, dilute calicos are almost exclusively female: the gene for coat color is located on the X chromosome.

The calico cat aspect (tri-color orange, black, and white patches) comes from X-chromosome inactivation, known as lyonization. Since coat color in cats is carried on the X chromosome, and females ...

A prime example of X inactivation is in the coat-color patterning of tortoiseshell or calico cats (Figure 1). In cats, the fur pigmentation gene is X-linked, and depending on which copy of the X ...