Pleiotropic effect of the Black crystal mutation on reproductive indicators in the American mink (Mustela vison)]

The parameters of reproduction were studied in American minks that were homo- and heterozygous for the Black crystal mutation (Cr). The given mutation that changes the hair pigmentation was obtained de novo duration selection of American minks for tame behavior. Apart from changed color, the following reproduction disorders were detected in the Black crystal mutants, as compared to standard animals: (1) delayed entry into the reproductive season in females; (2) greater percentage in both homo- and heterozygous animals of females bearing no offspring; (3) greater early postnatal lethality indices. The most marked suppressing effect on the development of offspring was detected in homozygous females (Cr/Cr), whose progeny perished within a few days after birth. An analysis of reproduction in mutants and standard animals is presented. An attempt was made to explain the conceivable mechanisms that form the basis of disorders detected.