The p6H, p25H, and pbs alleles at the pink-eyed dilution locus in mice (Mus musculus) cause sterility in males and semi-fertility in females when homozygous, while the pd, pun, p, and + alleles do not reduce fertility. Pituitaries from sterile males had significantly lower proportions of gonadotropic cells than pituitaries from fertile males. Ovaries from semi-fertile females contained large numbers of developing follicles, but no corpora lutea or corpora hemorrhagica were found. The proportion of polyovular follicles in ovaries of semifertile females was abnormally high.
Pituitary gonadotropins appear to be reduced in the sterile genotypes although the lesion cannot be localized. Possible relationships between these and other pleiotropic effects of mutant p-alleles are discussed.