Hello!

This is Cookie

Cookie is a male dilute tri-color (calico) cat.

Calico cats are recognized by their unique tri-colored coat that usually combines shades of black, orange, and white. They are not a specific breed, but a color pattern. 99.9% of calicos are female, with males extremely rare.

What a beautiful cat.

Klinefelter syndrome in cats

How do chromosomes determine coat color?

Coat color is determined by the genes present on the cat's chromosomes. Like humans, their genes act as instructions for the production of pigments that give color to a cat's fur.

The two main pigments determining a cat's color are eumelanin (black or brown) and pheomelanin (orange or cream). The genes that control the production and distribution of these pigments are found on several different chromosomes, but the X chromosome plays a particularly significant role.

The gene for orange and black color is located on the X chromosome. Depending on which allele it has inherited, a cat will express either orange or black color. If a cat has two X chromosomes, as with females, it can have orange and black colors. This is due to a process called X-inactivation or lyonization, where one X chromosome in each cell is randomly 'turned off' during the cat's development.

What does this mean?

Because the genetic determination of coat colors in calico cats is linked to the X chromosome, calicoes are nearly always female, with one color linked to the maternal X chromosome and a second color linked to the paternal X chromosome. In most cases, males are only one color (for instance, black) as they have only one X chromosome.

Male calicoes can happen when a male cat has two X chromosomes. This means that for them to be tri-colored, they would either have Chimerism or Klinefelter syndrome.

Generally, most male calico and tortoiseshell cats are infertile due to their genetic makeup.