Orange cats

Why is Marigold orange? Why are orange females rarer than orange males?

Female cats have two “X” chromosomes. Male cats have an “X” and a “Y” chromosome. All colors, including the orange color, are attached only to the X chromosome. I will call it Xo. The Y has nothing to do with color. A male cat XY who has a single Xo chromosome, now XoY, is always orange. That is why there are many orange male cats.

To get an orange female, she must have two orange X chromosomes. She must be XoXo.

Marigold’s father had to be an orange cat to give her the Xo gene, as only orange males carry the Xo gene. Her mother would have been at least a non-orange XXo. She would not have to be orange. Of course, she could have been an orange XoXo. In either case she donated one Xo, and the orange father the second Xo. The result is an orange Marigold female, who is outnumbered by orange males by a factor of 3 to one.

If a female has one Xo and the second X is a different color (X?), the two colors blend XoX? and you get tri-color or calico cats which are females. If Marigold’s mother was not orange, this is the color cat she would be. The rare Male cats like this are genetic mutations and sterile.

Do you have an orange female cat?

Marigold

Marigold

Since this photograph was taken, she has been to a groomer and had much fur combed out. She is ready for summer.

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One Comment

  1. If you have XoX on a female the colors don’t quite blend. Because males only have one X, the body has adapted to only having one X. Females, therefore, “turn off” one of their X in each cell at some point during development. From then on, child cells will have the same color as the active X, orange or black.

    If the decision to decide is early, you have large blotches as in the calico, If later when there are more cells, you have the more finely divided look of the tortoiseshell cat.

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