Various interacting genes determine coat color in mammals. At least five major genes, A, B, C, D, and S, interact to determine coat color in mice. The A-gene determines the distribution of pigments in the hair shaft. The agouti (A) allele is dominant to non-agouti (a). Agouti is the most common color in nature; it gives animals a grayish color or "salt and pepper" appearance (usually gray or dull brown). Non-agouti mice have solid dark pigments throughout the body. The B-Gene determines the color of pigments. The black (B) allele is dominant to brown (b). The B allele gives mice the normal agouti color in the presence of the agouti trait, but gives solid black in combination with the non-agouti trait. The C-gene permits color expression. Color expression (C) is dominant to no color expression (c). The homozygous no color expression (cc) combination is epistatic to the other color genes, and as such, animals with the homozygous (cc) combination will lack coat pigments and will be albinos. The D-gene controls the intensity of the coat pigment specified by the other color genes. Full expression of coat color (D) is dominant to dilute or "milky" expression (d). This effect is due to an uneven distribution of pigment in the hair shaft. Hence, dilute agouti, dilute brown, and dilute black coats are all possible. The S-gene controls the distribution of coat pigments in the body, whether the coat pigments appear over the whole body or appear in patches (piebald). Whole body color distribution (S) is dominant to spots distribution (s). This pattern can be superimposed on any of the coat colors - with the exception of albino.
Use the above information to answer the following questions.
a. What are the possible genotypes of (give all possibilities):
(i) dilute agouti mice
(ii) solid brown piebald mice
(iii) albino mice
(iv) solid black mice
(v) dilute brown mice
b. If a dilute agouti mouse was mated with a mouse that had a solid brown piebald coat:
(i) What are the possible genotypes of the parents? (clearly identify each parent genotype)
(ii) Using only the parents with the most heterozygous combinations, give all possible gametes produced by the two parents.
(iii) For the two combinations in (b), give the phenotypic and genotypic ratios of the progeny in the F1 generation? (Show all your work and be careful to give the proper coat color of the progeny)