GENETIC DETERMINATION OF COAT COLOR AFFECTS TESTICULAR STEROIDOGENESIS IN THE MUSTELA-VISON

Coat color genes in mammals are known to be developmental genes with w ide pleiotropic effects. The present study was undertaken to study tes ticular steroidogenesis in American Mink (Mustela vison) of various co at color phenotypes. No differences in testicular steroid levels were observed between fertile and infertile mink with the standard phenotyp e and genotype (BE jj MM PP). Mink with the opaline phenotype and geno type (bb mm pp), were found to have in their testes, 20-40% higher lev els of progesterone, five times higher levels of 17-hydroxyprogesteron e, and eight times higher levels of testosterone, than the correspondi ng values in other mink. No other differences were observed among the different types of mink. Since the genotype of the opaline mink differ s from the other mink studied, only in their combination at the pastel (b) and moyle (m) loci, their bb mm genotype could be assumed to be r esponsible for the increase in testicular steroids.