Tortoiseshell colourings

I love tortie cats, but never had one till recently, when two came into my family within a few months of each other. Obviously, they are both female, but this set me thinking, since they are so different. Topaz is a mix of rich red and brown patches, with some black and white. Bluebelle is blue and cream, with the hairs much more integrated, though she does have some patches of each colour. I know nothing of their parentage - they were both stray kittens brought to me, the crazy cat lady.

I can see that Topaz is very much the female version of a red tabby , probably with a black or black tabby mother (Her brother, Amber, who is also with me, is a very deep red tabby). But is there a male version of a blue tortie? What are Bluebelle's parents likely to have been?

This is Topaz

And here is Bluebelle

Their parents could be of any color under the sun. Maybe one was a Tabby and the other was a Calico? My tortie is black and orange, her mother is grey and white and her dad is pure white. She had 3 brothers, one pure black, one pure white and one all grey. It's a mystery where her and her all black brother got their colorings cause her mom and dad were both indoor only cats lol.

Could be:

black female + orange male

orange male + black female

tortie female + black male

tortie female + orange male

The X chromosome is what determines coat color. It's possible for a male to be a tortie, but it's rare because it requires a genetic mutation called XXY (a.k.a. Klinefelter) syndrome. To get the tri-color coat, one X chromosome has to carry the orange gene, and one X chromosome has to carry the black gene to get the tri-color coat. That's the simplistic explanation. I don't want to get into discussion about alleles because that's a little over my head, but I can tell you that it would be extra extra extra rare for a male tortie to father a litter because most XXY syndrome carriers are sterile.

The person to ask here is Prof. Lyons.

She's our resident genetics expert... maybe a mod could move this to the genetics section?

Edit: Oops... nevermind. It's already in the genetics section

The non-tortie version of a blue/cream tortie would be either blue or cream . A gray cat or a very light orange cat, in non-show terms. Blue and cream being the dilute of black and red, respectively. I'm not very well-informed about how the dilute gene works. But, yes, she had to get blue from one parent and cream from the other, which parent was which is impossible to say.

Amber and Topaz' mother had to be either red tabby or a tortie herself, because boys get their color from their mother, so Amber had to get the red from her. Topaz is a very lovely classic tabby/tortie (torbie), which I've never seen before. I don't know if it's particularly rare or I just haven't seen it though :lol3:. Is Amber also a classic tabby (swirls not stripes)?

jmljml19 said:

Their parents could be of any color under the sun. Maybe one was a Tabby and the other was a Calico? My tortie is black and orange, her mother is grey and white and her dad is pure white. She had 3 brothers, one pure black, one pure white and one all grey. It's a mystery where her and her all black brother got their colorings cause her mom and dad were both indoor only cats lol.

Click to expand...

The all-black boy got the non-dilute black (gray is dilute of black) from his mother, obviously the gray one got the dilute. White is a masking color---they can be any genetic color "under" the white. The father cat had to be red "under" the white in order to make a tortie girl---she got the non-dilute black from her mama and the red from her daddy. The white boy kitten had to be either black or gray "under" his white.

Thanks for your comments - I did not know that red is transmitted through the female line - I had assumed that both Amber and Topaz got their red from their father.

AS for the tabby markings on Topaz, I have never seen a tortie with such definite tabby marking either, but apparently it is not uncommon.
Here is a picture of Amber, her brother. He also has classic tabby swirls, plus the very rich red colour.

My wild feral, Russell, is that rich red color with white markings too. He also has the 'swirls'. When people see him they always comment on his coloring. Your Amber could be his son, they look that much alike!

I did not know that red is transmitted through the female line - I had assumed that both Amber and Topaz got their red from their father.

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Just boys get their color from the mother only---girls get one color from each side . So that means every red male cat has a red or tortie/calico mother.

Wow, Amber is gorgeous too! I love classic tabbies. I have a deep red classic tabby named Nacho, but he's from a feral litter I brought inside and he's never tamed :/. So it's hard to get pictures of him. His mother is a red mackerel tabby, just a regular shade, not deep like his, and his father (I think) was the blue tom who was hanging around (I did see the mama mating with him but I suppose she could have hooked up with another male some other time), so I always wonder where he got his deep color. His 3 sisters are all torties, but only one has the very deep red like his.

That is really interesting - so their mother was red or tortie and the father could have been any colour.

Very interesting thread. Just wanted to add that Prof. Lyons told me you guys did a terrific job explaining everything, she didn't have much to add. Well done!