Coat color in mice is another excellent example of epistasis. in mouse Coat color in mice is another excellent example of epistasis. In mice agouti (A) is the wild type, yellow, coat color, which is dominant to the black (a) coat color. A different gene controls whether or not the pigment is deposited in the fur. The dominant allele (D) allows the pigment, while the recessive allele (d) causes albinism in the mouse, regardless of the A/ a allele. If a mouse with the genotype AaDd is crossed with a mouse that has the genotype aaDD, what will the phenotypic ratios of the offspring be:___________