# Homozygous Lethals



## jaroslava (May 16, 2010)

Hi all,

I remember reading quite some time ago about some genetic combinations that are lethal. I know that there is Lethal Yellow of course, Ay, but can't remember any others. I have a vague notion that variegated might be amongst them, but it seems variegated as such doesn't exist in Australia, that it is broken marked roan. So would there be any lethality in breeding those for any reason? Does anyone have a resource or list they could direct me too please?

Cheers,
Jenn
Jaroslava Mousery


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## PPVallhunds (Jul 26, 2010)

as far as I know the leathal ones are dominant red, verigated and rumpwhite. with the reds and rumps the homozigus ones are reabsorbed but with veri they are born but die with in a few days. 
There is also brindle (the one we have in the uk not usa) any males born are apperantly white and normay die.

I don't know of any combos of different allies that are leathal so getting the pied gene along with the roan gene to make a mouse simmaler to vari should not cause any problems.


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## jaroslava (May 16, 2010)

Thank you for that. Looks like we might be in the clear, unless there is something else we've been missing, as we don't have the dominant red, or rump white either. I think there is something else going on with the Ay fawns but will have to take closer note to work it out.


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## Laigaie (Mar 7, 2011)

Ay is dominant red. I am confused about what kind of fawn you're describing.


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## PPVallhunds (Jul 26, 2010)

Fawn is pink eye ay red


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## Serena (Dec 29, 2011)

I always thought, fawn could be both: Ay or ee in the pink eyed version


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## PPVallhunds (Jul 26, 2010)

Don't know about ee but as the op said ay I just assumed they only had ay where they are.


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## Autumn2005 (Apr 21, 2010)

Not sure about Australia, but pretty much only imported mice have ee in UK, and only imported mice have Ay in US.


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## Cait (Oct 3, 2008)

We don't have RY (ee) in the UK.


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## Autumn2005 (Apr 21, 2010)

I wasn't sure if any breeders had decided to import the RY (ee) gene to the UK (though heaven knows why when you already have such beautiful mice), which is why I added the import thing. Just as probably all the mice in the US that have Ay have imported ancestors.


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