# Query for US breeders - recessive yellow



## Cait

I am hoping that someone will be able to help me with some photos of the different expressions of the RY gene, especially with splashed. I have a baby in the nest who had fairly bright splashes but has darkened a little as he has aged (still not weaned). It is probably a cham, but since the splashed descend from US stock that was imported many many generations ago, I thought that it might be worth putting him back to his mother in future to try and find out more about the genetics. It would be good if I had some examples to compare to so all input appreciated


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## MojoMouse

I just thought I'd bump this, I'm interested as well. I don't know anything about recessive yellow, and can't find much information about it. Can it be bred to a strong yellow/fawn/red colour?


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## Jack Garcia

Recessive yellow _can_ get dark and ruddy, but I've never seen it as dark as a good dominant yellow. That doesn't mean that it can't get there, necessarily, just that it hasn't. Even when its dark, though, it tends to have a dull quality to it that Ay/* mice don't. Christina (Stina) has had some decent examples in the past. Here is her flickr account with the "recessive yellow" tag chosen: http://www.flickr.com/photos/stinaksu/t ... iveyellow/

Jennifer H (who is no longer active on this forum) also bred some a few years ago. I did not take this picture, so I will link to it instead of posting it as an image: http://i236.photobucket.com/albums/ff1/ ... CN3086.jpg If I remember correctly she was part of the group who had imported dominant red and used that to darken her recessive yellows.

Compared to dominant yellow, recessive yellow has no associated breeding or reproductive problems, no associated health problems related to obesity, and no heterozygous lethal aspect (it is a homozygous variety) or tumors. That's why the Germans and some Americans have moved toward it. It tends to "muddy up," and get sooty, though, and some of the ones I've seen had very wonky molts (though I don't know if that's endemic to the variety).

(There are uniquely four ways to get reddish mice: Ay/*, Avy/*, A/* with p/p, and e/e).

All types of red varieties appear better on a cinnamon or chocolate background because black or agouti backgrounds can retain too much black pigment.

A few years ago it was a fad of some of the newer breeders to breed recessive yellow everythings, so I'm sure there are more pictures out there. I just don't have any off-hand. I've never bred the variety on purpose!

The problem with recessive yellow splashed is that is that e/e dilutes anything that is also C-diluted to white or nearly-white, so you'd have a white mouse with off-white or yellowish splashes. It's not very distinctive.

By the way, the same genotype that causes red guinea pigs also causes recessive red mice, so roughly anything that is true for red guinea pigs is also true for recessive red (recessive yellow) mice. You might ask some breeders of red cavies.


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## Stina

the gene responsible for recessive yellow/red mice is also responsible for golden retrievers, yellow labs, irish setters, and pretty much any yellow/red dog there is. The same range of colors from nearly white to extremely deep red should be possible in mice that are e/e. I believe e/e has the potential to produce just as deep, if not more deep, reds as A^y. It has been a MUUUUCH shorter period of time that e/e has been bred for deep reds than A^y though, so I do not find it surprising that very few have been bred that come close to rivaling good A^y reds. The recessive aspect of e/e slows down the process fo deepening it, and also the fact that you cannot easily tell the difference between a young e/e and a young A^y so you have to be careful who is used for what...it is difficult to deepen the reds in e/e mice while keeping the mice e/e.

With a combo of what I've experienced and seen from others, both A^y and e/e are both prone to sootiness when not bred against it and bred with black backgrounds. e/e possibly a little more only b/c they can have a double dose of the non-agouti gene. Chocolate or cinnamon backed A^y or e/e cannot have black sootiness...since chocolate and cinnamon cannot produce black. Moulting issues and such I think are from poor breeding or health problems when young. I've very very rarely seen any moult lines in an e/e mouse, except when not chocolate/cinnamon based.

As far as splashed and tricolor would go...as jack said, you are likely to get poor definition...though with very careful breeding you could probably get something pretty decent looking. You would definitely need to start with the deepest reds you could find, and I would only use c^e as the c-dilute....c^e seems to remove less of the pigment in the brown/red ranges than the other c-dilutes, so you would keep more cream in the diluted areas. If you were to start with animals that are too light you would likely get cream on white with little definition between the splashed and unsplashed colors....with a deep rich red you should be able to get moderately red splashes on a cream diluted shade.


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## moustress

It'll be interesting to see how my 'new' recessive yellow/red tris come out. Roland had opined that the ones I produced in the past were A^vy, in which case it'll be a totally new ball game, as I lost all those in the accident except for two bucks, one of whom never produced any more litters, and other produced Tracker. Any yellow tris or splashed from his line might be A^vy, the others are all going to be ee.

Here's the pair that produced Tracker; that's him as a baby second from the bottom in the first photo. Windflower prbably should have called a yellow splashed.

Windflower is a satin tricolor(sic) and Gull is a BEW from a brindle/tri litter.


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## MojoMouse

Thank you so much for the effort taken in such informative replies!  It's greatly appreciated. It seems to be a variety with a lot of potential, but none of the drawbacks of Ay. If we had them here I'd work with them!


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