What are tortoiseshell and calico cats ?

[amoore]

I found this neat article in a little paperback book and wanted to share this with you . The book is called "Why do pets do that ?

A tortoiseshell cat is one whose fur is a mottled black and orange color . A calico cat is black and orange with patches of white . The odd fact about both these types of cat is they are almost always female. Male calico and tortoiseshell cats are rare . Only one in every 3,000 calico cats that lives past kittenhood is a male .
The explanation for this strange occurrence comes from genetics . In the cells of all animals are threadlike structures called chromosomes. Carried on the chromosomes are tiny coded messages known as genes . An animal's genes determine almost everything about it - whether it is male or female , what color its eyes ,skin and hair (or fur) are ,and a lot more
Chromosomes as we know, come in pairs. One of these pairs determines whether the animal will be male or female .Females have two x chromosomes ,while males have one x and one y. In cats the coded messages for black and orange coat color are carried on the x chromosome,but not the y.
A male cat, because he has only one x chromosome, can be either black or orange in color .In order to be black and orange, the cat needs two x chromosomes, one carrying the gene for black fur and one carrying the gene for orange fur Since any animal with two X chromosomes must be female, all black and orange cats are female.The extremely rare male calico or tortoiseshell cat has three sex chromosomes,two X and one Y.

[jenluckenbach]

the last sentence has cleared up my question on HOW CAN A CALICO BE MALE? I never thought of having 3 sex chromosomes. Thanks for the info.

[Randi]

That was very interesting. I knew that most orangies are male, but the last bit was new to me. Thanks for posting!

[PayItForward]

Interesting insight into my Milly & Sandy.

[Kirsten]

The extreamly rare male calico or tortoiseshell cat has three sex chromosomes,two X and one Y.

That's new to me, thanks, very interesting! All I heard so far was that if there are male calicos, they are most likely hermaphrodites and can't have babies.

Edited because it just hit me that in Luna's litter, there were 4 tabby girls (including Luna) and one boy - black and orange!

Kirsten

[trayi52]

Well if i had known that I wouldn't have been trying so hard to find out what Grover was. Of couse she still would have been named Grover, what else do you name a cat that was found in a trashcan? Grover of course, and the grandchildren insisted so what else was I to do. I never knew that about the tortises and the calicos though. I had calicos when I was growing up, and they were females. Didn't enter my mind there was a reason for it.Thanks for the info amoore.

[amoore]

this is from CatFancy magazine (Jan2002) article by L.Shelton-

"the calico cat takes its name from a colorful cotton cloth imported from Calicut, India.

"the only breeds that can't have calico kittens are Abyssian, Burmese, Bombay, Chartreux, Egyptian Mau, Havana Brown, Korat, Ocicat, Russian Blue, Tonkinese, Siamese, Singapura, Somali...all other breeds have the genetic combinations necessary to make calicos.

"logic leads us to the conclusion that male calico and tortiseshells cannot exist, because males have only one x chromosome and, therefore, only one of the two basic colors needed...(but)

' A recent study of a group of 10,000 cats coming into veterinary clinics...found the incidence of calico/tortiseshell males to be 4 cats per 1000.

"11 of these male calicos were studied further...some were XXY (sterile) but over half were determined to have both XX and XY cells , and to be fertile.

[amoore]

Kirsten can you tell me how the little boy kitty is doing ?
Trayi52 you made a lucky find , when you found grover !
My research on these wonderful cats has really been fun !
I don't aim to stop , cats are so interesting !As well as loving wonderful creatures to own ! Or should i say to be owned by ?