female red tabbies, what are the genetics?

Hey folks,

I've wondered this for a while now and thought I'd "ask the experts". I apologize if this has been talked about before.

My brother has a female (spayed) red/white mackeral tabby DSH. I had always heard that this was impossible and that if it happened, the female would usually be sterile (same with tortoishell males).

I was wondering if she could have gotten a copy of the red gene from both parents and not gotten the black gene, or would she have to be a very odd "xxy type" female?

What combinations of parents would cause a red female tabby? (i.e. red tom and calico queen, etc?).

And, one final question... does the "cream" (dilute red) also function/work the same way (with regards to gender) as the regular red does?

Thanks for your time and help!
Art

The color gene comes on the X Chromosome. In the cases of males, they only get one X so they either get Black or Orange. Females get 2 Xs so can get Black-Orange (Tortishells) Black-Black (Black) or Orange-Orange (Orange). They are fertile, regular females. It is just rarer to get the Orange-Orange combination.

Males on the other hand can only get Black-Orange in the XXY and are infertile because of that defect.

Red females are not that rare nor are sterile.

You need the Red gene from both parents (on the X chromosome) for a female to be "red". So:

Tortie female (Red X, Black X) to a Red male (Red X) could produce either a red female or a tortie female.

OR

Red female (2 Red X's) to a Red male (Red X) you would get ALL red males and red females.

If both parents are carrying the dilute gene you can get cream females or blue cream females.

Thanks for your help!
That makes much more sense to me. I suppose the "rarity" of it is an old wive's tale of sorts.

Thanks again!
Art

I believe that only about 10% of red tabbies are female. IT is somewhat rare, but not nearly as rare as the male tri-color.

My friend had a litter of kittens, the mother was a stray rescue, she was a red tabby and all the kittens were either red, orange or cream.

Neko - you only have a choice of red or cream (the dilute of red). But you can have various shades of red - from dark to lighter

My oldest cat Scruffy is a red tabby female. She also had a litter of kittens.

The shade of red in non-dilutes is generally determined by which base colour (black or brown) the cat is genetically - ie. cats that are genetically B/B or B/b (black) but with the orange gene will produce a darker shade of red pigment than those which are genetically b/b (brown) and also have the orange gene. It's quite a fine distinction between the two though, I doubt anyone could visually tell the base genetic colour of a red cat by visual observation only!

ETA: forgot to add that on top of that there are also multiple genes which affect the depth of red colour expressed on top of that determined by basic black/brown colour genetics - they aren't yet full understood but are given the general name 'rufous polygenes'.

Interesting about the genetic black influence.

So how do you explain this:

My tortie rex (mainly black) was bred to a black smoke male. She produced 3 red tabby males in her first litter. I got a very dark red classic tabby male (surprise) and a medium red mackeral tabby male and a true red (light) male. He didn't have the tabby markings but was almost a true solid red - kinda looked like a red aby without ticking.

We do know the father was carrying the classic tabby gene

Thanks again for going more in depth about it. I think genetics are fascinating and if I ever become a breeder I will probably enjoy that side of things (or so I say now...).

I recently rescued a couple of feral kittens from a female calico. They are two brothers, one black and white, the other a red mack. tabby. And, within a couple of weeks of finding them, we found a cream and white male at our home...That was the first time I'd ever seen a cream in person and they are georgous! So, until we found a home for the cream boy, I had a whole spectrum of colors (including my brown spotted tabby male). Kinda interesting when they were all lined up.

Thanks again for your expertise!
Art