# The Tan Gene



## hyshqa

Of the show line mice I got recently I was told that the black female I've got is a carrier of the tan gene, identified because she has a small number of tan coloured guard hairs on her belly/sides in front of her back feet (not very visible unless you look for them), but from the reading I've done I'm sure I read that the tan gene is dominant so that if she did have one tan allele that would make her a 'carrier' it would show on her phenotype? All of his other black mice he said were fox carriers because of equivalent _white_ guard hairs which I could believe because fox is recessive, but I just don't know about the 'tan carrier' I have. She and the fox carriers came from at least one black tan parent and are all siblings, so could she be a fox carrier with slightly tan guard hairs because of her parents?

I plan to put her to my fox buck once he's a little older so I suppose I'd find out then; my knowledge on genetics is poor but if I've worked this out right then if she's a fox carrier half the litter would have the fox phenotype and the rest would be carriers, whereas if she's a tan carrier (if that's actually possble..) then none would show either fox or tan but would all be a combination of fox and tan carriers?


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## ian

tan is dominant so she cant be a 'carrier' could be a poor tan but I think you would notice a pale belly on a black, tan gurad hairs can be caused by breeding tan into self lines and makes sense she has them if she has tan parents. Possibly she could be have the potential to create foxes.It depends what your fox buck is, whether he has two tan genes or just one?

If you buck is homozygous tan and if your doe is carrying 'fox' then you will end up with 50% fox, 50% tan but they will be carrying fox. 
If your buck is heterozygous for tan and your doe is carrying fox then you should get a fairly random mix of selfs, foxes and tans but atleast they will all be atleast carrying the recessive fox causative genetics.


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## WillowDragon

Tan is dominant, it would show with only one copy of the gene... Tan hairs are normal on pet type mice hon, in fact show breeders have a devil of a time breeding them out.

A fox mouse is a tan mouse with the c locus gene to dilute the red to white, generally the chinchilla gene. The chinchilla gene is recessive, but without the dominant tan gene aswell, you wouldn't see it.


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## hyshqa

Well that's a lot more complicated than I thought it would be! Looks like I've got a LOT more research to do before I get down to breeding these two 

How on earth did the fox buck come about then (a champagne siamese fox at that!!)- both his parents are chocolate selfs, as are his grandparents, and all his siblings were chocolate selfs (though I think there were some very slightly broken chocolates). He was just a weird one that was popped out! :lol:


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## WillowDragon

Any c locus gene dilutes the red gene... A siamese fox is simpley a siamese with the tan gene.


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## hyshqa

I see, thanks  But then how did he aquire a tan gene if it is dominant but neither of his parents or grandparents had tan or fox phenotypes? Can it come in different forms that don't show or something? (Or is he just a mystery! :? :lol


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## nuedaimice

Is he really a fox or does he just have a light belly color because he is a siamese or does he have a white spot on his belly tracing back to the spots earlier in the pedigree?

A fox would not be possible out of two Self mice. And by Champagne Siamese Fox, are you saying he is Champagne in color (which is normal for a Siamese) or he has Champagne colored points? Siamese can have lighter bellies which is a fault, but if he is actually a Siamese Fox, then I would question the parentage. Especially if it is a line of nothing but Chocolate Self bred to Chocolate Self. My two questions would be where did the Tan (dominant gene) come from and where did the Siamese pop up from (were there more Siamese mice in the line)? And are his points dull looking like he is actually a Chocolate Siamese?


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## moustress

nuedai: that's one way to explain the diluted belly.

Either that or the odd siamese mousie carries tan, as that is one of the ingredients for fox. Only through test breeding could you know; unless the 'breeder' has some other info to explain this.


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## hyshqa

I'm hardly an expert but I'd say he's definately a fox:










So if fox is physically impossible to get from two selfs then I probably wasn't told the truth about his parents. That or I misheard him or something 

I've been told recently through this forum that he's not a champagne, he's a shaded siamese ?. Here he is so you can make your own judgement:










His breeder wouldn't have any more of an idea, he seemed as surprised as everyone else to see his chocolate self doe pop that out and said he must just be a throw back from way back up his parentage that he didn't know about. I'll be breeding from him with at least one of my does so I'll see what I can get from him 

Thanks so much for all the information guys, very much appreciated!


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## nuedaimice

I posted in another thread that he looked like a Colorpoint Beige (U.S.) or a Black Eyed Siamese. I can't tell if his points are chocolate or poor black points.

Now, either the parentage is wrong OR there is the off chance that it is a random mutation that caused the a^t gene to appear. I have heard that it happens a lot in UK stock, but I don't how true that is. And that the tan gene is the most common for it to happen with.


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## cjdelphi

I cross bred a PEW (bought store mouse) with a Wild Mousie I managed to rescue from my Cat... Decided (after reading this thread) to check her underbelly out, and there's definitely some light brown patches, not much though...


















The rest of the litter had a poor black in, ginger's all kinds...


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## SarahY

> She and the fox carriers came from at least one black tan parent and are all siblings, so could she be a fox carrier with slightly tan guard hairs because of her parents?


She can't carry fox because that needs the dominant tan gene and the recessive chinchilla gene. She doesn't have the tan gene but she could be carrying the chinchilla gene (a/a C/cch). If she is carrying it then she would have tan guard hairs and if you bred her to a fox you get tans and foxes in the litter. If she was a chinchillated black (a/a cch/cch) she'd have white guard hairs and you wouldn't get any tans if you bred her to a fox, only foxes.



> I've been told recently through this forum that he's not a champagne, he's a shaded siamese ?. Here he is so you can make your own judgement


I don't know what a 'shaded' Siamese is supposed to be, as all Siamese are shaded. A champagne Siamese would appear pink eyed white. Your buck is a black eyed Siamese fox (at/* ch/ce), but you wouldn't get proper foxes if you bred him to a fox, you'd get sepia and burmese foxes. This is because on that mouse the Siamese gene is what's making the tan white, not the chinchilla gene.

Hope this helps 



> Wild Mousie I managed to rescue from my Cat... Decided (after reading this thread) to check her underbelly out, and there's definitely some light brown patches, not much though...


I don't think that's a wild mouse; it doesn't look like one and it's very calm for you to hold it like that!


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## cjdelphi

the wild one i caught i released ages ago, she's his daughter in the picture...


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