The Genes!

[Thestarcatcher]

My friend is breeding her Egyptian Mau, with her dsh. In hopes of creating a spotted orange cat...is this possible? I have talked to her about spay and neuter and benefits, but she is hoping to create a new “breed” which I also told her was a lengthy and unlikely process. The mau is pedigree, and male, and the female is a dsh orange tabby who looks A LOT . Like my peanut (who got the snippy snippy when she was 12 weeks). What should she expect? I know there are a few good geneticists on here!

1CatOverTheLine @Kieka lutece

 

[lutece]

What exactly is the question?

 

[lutece]

If your friend wants a red spotted "breed" I would suggest that she just get herself either a cinnamon spotted Ocicat, or red spotted Oriental. Those are common enough that she could find herself one. Cinnamon spotted Oriental would be a possibility too.

 

[lutece]

I looked through your previous posts to see what color the Mau is. Apparently your friend bought him with an agreement to neuter him. She should honor her agreement and do that.
A True Egyptian Mau?

 

[1CatOverTheLine]

My friend is breeding her Egyptian Mau, with her dsh. In hopes of creating a spotted orange cat...is this possible?

The answer to the initial question is, "no," since you're asking about the creation of a Breed - i.e. one which consistently throws true to a particular standard. Have your Friend read this simplified overview regarding the way the spotting allele works:

Spotted cats have at least one copy of the Striped version at the Tabby gene AND a copy of Spotted at the Gene 2 location.
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[Thestarcatcher]

What exactly is the question?

She was wondering if it was possible to create a spotted, orange tabby, using her spotted cat and her mackerel tabby. She said she is going to get him fixed, but wanted him to produce a litter so she could keep the offspring.

 

[Thestarcatcher]

If your friend wants a red spotted "breed" I would suggest that she just get herself either a cinnamon spotted Ocicat, or red spotted Oriental. Those are common enough that she could find herself one. Cinnamon spotted Oriental would be a possibility too.

And exactly what color variations. She said she did have a neuter agreement, however she said that the lady who she got him from unfriended her after she bought the cat and hasn’t asked since, so she has decided to take matters into her own hands. Not responsible, but she informed me that she wanted a small litter in order to keep one of the kittens.

 

[Willowy]

If the mama cat is orange, all her male offspring will be orange too. So yes on the orange part, unless she has all girls. The spotted part is a little more uncertain.

 

[abyeb]

She could get orange spotted cats, but they won’t be a new breed. EMau x DSH will be DSH.

 

[lutece]

She said she is going to get him fixed, but wanted him to produce a litter so she could keep the offspring.

Breeding a cat and then getting him fixed doesn't count as honoring a neutering agreement. It doesn't matter if the breeder isn't friendly or talkative. Your friend should honor the agreement she made when getting the cat. That is not just about responsible breeding, it is about being a responsible, trustworthy human being.

If your friend wants to modify the agreement she made, she should get in touch with the breeder and discuss it. If she is thinking about using the cat for breeding, she should work to develop a better relationship with this breeder, and learn as much as she can about his pedigree and the health of his relatives. Perhaps there is a reason this cat was sold as a pet; there may be something problematic in the bloodlines that would be a bad idea to perpetuate through breeding.

 

[lutece]

She was wondering if it was possible to create a spotted, orange tabby, using her spotted cat and her mackerel tabby.

In addition to the reference quoted by 1CatOverTheLine, here's another reference with information about the genes involved in spotted tabby cats.
Defining and Mapping Mammalian Coat Pattern Genes: Multiple Genomic Regions Implicated in Domestic Cat Stripes and Spots
In this study, they actually used an Egyptian Mau. The first cross of Egyptian Mau to non-spotted tabby resulted in broken mackerel patterns, not fully spotted individuals. That is what I would expect with this cross. Males would be broken mackerel red tabby, females would be broken mackerel torbie. In order to develop a true-breeding bloodline homozygous for spotting, your friend would then need to cross these F1 individuals with additional spotted cats. Where would your friend get these spotted cats? Hopefully your friend would not cross the F1 generation back to the Egyptian Mau father!!!

If your friend is earnestly interested in developing a breed or bloodline, her first step would be to develop good relationships with other breeders who can provide not only breeding stock, but also reliable information about the genetic and health history of all known relatives (not just those in the cat's pedigree, but also other relatives). Any time a new breed or color is being developed, it is inevitable that at some point there will be linebreeding or even inbreeding to fix the traits. It is essential, then, to have a good plan, and start with the most genetically sound and diverse breeding stock that you can, because the inevitable linebreeding will tend to fix negative traits as well as positive ones. It doesn't sound to me as though your friend is starting off on the right foot for this type of project.

 

[1CatOverTheLine]

It is essential, then, to have a good plan, and start with the most genetically sound and diverse breeding stock that you can, because the inevitable linebreeding will tend to fix negative traits as well as positive ones.

lutece - I hadn't much of anything further to offer here, but pared down your quote because I thought it imperative that this clause be repeated.

To be honest, knowing what little I know of modifiers and transfer proteins in Tabby genetics, I'd be more inclined to begin studying Bengal genetics, since in so doing, you'd be beginning with a Asian Leopard Cat [i.e. Prionailurus bengalensis bengalensis] foundation - a cat with an enormous variance in genetics which still consistently throws the same spotted coat (see Shomita Mukherjee's ground-breaking paper here):

Ecology Driving Genetic Variation: A Comparative Phylogeography of Jungle Cat (Felis chaus) and Leopard Cat (Prionailurus bengalensis) in India

After I was comfortable with ALC genetics (and perhaps even Tsushima Leopard Cat [Prionailurus bengalensis euptilura] genetics, as I consider the matter), I'd endeavour to have a long, intensive conference call with Les Lyons and breeder Terra Sinclair in Sacramento [Pocket Leopards] (and perhaps with even with Liza Gershony at U. C. Davis as well), regarding spotted phenotypes and the interaction of the ALC Agouti A2 allele, found in Savannahs and Bengals.

Beginning a New Breed program for, "a spotted orange cat," with Egyptian Maus - a breed in which melanosythesis switches back and forth between pheomelanin and eumelanin - rather than a breed or landrace in which the co-dominant O is already consistently throwing pheomelaninistic cats, is roughly the equivalent of trying to hit a tennis ball over a ten story building using a toothpick, since O is gender-linked, hence using an Egyptian Mau Sire would never result in furthering your goal.
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