genes for coat colour in cats

[Draco]

Is it possible for a tom cat to have tortise shell coat?

In biology I was told that some of the genes for coat colour where only found on the X chromosome not the Y, and that tortoise shell coats where only possible on females yet a friend of my parents has a male tortoise shell.

[MrMistery]

It might a cat with Klinefelter

[Draco]

So with the extra X chromosome it means it has two coat alleles instead of one therefore allowing the tom to have a tortoise shell coat if one cat passed on the ginger allele and the other passed on a different allele.

Intresting, Thanks MrMistery.

[canalon]

You should read about the calico phenotype

[Draco]

What I dont understand is how the extra X chromosome occurs. any ideas.

[Darby]

During sex cell production (meiosis), a chromosome goes the wrong way. One resulting cell is missing an X, the other has an extra.