In Labrador Retrievers, coat color is governed by two intera…
In Labrador Retrievers, coat color is governed by two interacting loci. Locus B determines pigment density (Black B is dominant to Brown b). Locus E acts as the control switch for pigment deposition in the hair follicle. If a dog inherits the homozygous recessive genotype $ee$, no dark pigment can be deposited in the fur, defaulting the coat to a yellow color regardless of the alleles at the B locus. If you cross a black lab (BbEe) with a brown lab (bbEe), what proportion of the resulting litter will be yellow puppies?