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Black x Brindle Question

Tue Oct 23, 2018 10:44 pm

I just can't wrap my head around genetics! Can someone help straighten me out?

I have a brindle pied buck, so Avy ss?, who came from Avy ss(pied brindle that had no stripes, I originally thought to be recessive yellow) crossed with a pied black(so would that be aa ss?)

And a black self, so aa, that came from an agouti, unsure of father's genetics. Wouldn't this result in an all brindle litter? I was told by a breeder it would result in blacks, but I guess I'm not understanding how the Avy reconciles with aa, but I thought brindle was dominamt over black?

Re: Black x Brindle Question

Wed Oct 24, 2018 2:10 am

Brindle Piebald = Avy/* s/s
Black Piebald = a/a s/s

Brindle and Black are both on the a-locus. Dominance within the a-locus goes as Brindle, Agouti, Black (only including the genes within this scenario for simplification). The Brindle buck you bred could be Avy/a, Avy/A, or Avy/Avy. If we put these combinations with the Black Piebald...

Then, we can be sure that all the offspring will be Piebald. However, the coat color is dependent on the genotype of the Brindle buck. If he was, then...

Avy/a = Some Brindle and Black pups, all will carry Black
Avy/Avy = All Brindle pups, all will carry Black
Avy/A = Some Brindle and Agouti pups, all will carry Black

Re: Black x Brindle Question

Wed Oct 24, 2018 12:52 pm

I think I've got this figured out, I forgot to pay attention to heterozygous... I know what the pieds would throw, I was just trying to figure out what their offspring paired with a black self would result in.

Wouldn't I know for certain that my buck is Avy/a, because he's brindle, and I know that his father was brindle and his mother black? If he had gotten anything besides Avy from his dad, he would be either agouti or black, right? And he couldn't have gotten anything but a from mom. So pairing him with a black a/a will result in half black and half brindle? I know pied is recessive, so none of that. I'm confused how the A would get passed down through a/a or Avy/a, though.

I'm not even going to touch the brindle modifiers, lol!

Re: Black x Brindle Question

Thu Oct 25, 2018 3:55 am

If his mother was Black and father was Brindle, then the buck is Avy/a.
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