Guess the Genotype #84

Can you guess this litter of puppies' genotypes? Their breed?

Image is from Wikimedia Commons under a Creative Commons license

These puppies are Bedlington terriers, a breed that is born dark, but will fade with age. Due to this, he breed looks quite different when all grown up. So, what are these puppies' genotypes?

All of the puppies are dominant black. Though tan points are possible in the breed, none of these pups have those markings. However, it's still possible that some of them may be carriers for tan point. Since there isn't any other form of the Agouti locus seen in the breed, it's like the breed is fixed atat tan pointed. Despite this, most dogs also have at least one copy of the dominant black gene, which hides the tan points. Since these puppies are all dominant black, they are either KK dominant black or Kk dominant black (carrying non-black). The reason for the color change from puppy to adult is thanks to the graying gene. Though the gene has not been mapped on the canine genome, it has been confirmed via breeding data and is believed to be dominant. Since Bedlington terriers all fade with age, the gene must be fixed in the breed, making all Bedlingtons GG gray.

Lastly, there is one brown puppy, a color caused by the recessive liver gene. Since there is only one puppy of this color, I suspect that both of the parents for the litter carried brown. Due to this, there are probably carriers and non-carriers for the liver gene in the litter. So, the brown puppy is bb liver and the black puppies are either Bb non-liver (carrying liver) or BB non-liver.

So, that's atat BB/Bb/bb GG KK/Kk or graying black and graying liver.