Variation in chromosome number in the blue fox (Alopex lagopus) and its effect on fertility

摘要

Effects on fertility exerted by polymorphism for a centric fusion between chromosome Nos. 23 and 24 were investigated in the blue fox (Alopex lagopus). The pregnancy rate was not affected by the chromosome type, but the litter size was lower for the centric fusion heterozygotes compared to the homozygous animals. The pregnancy rate was affected by the time of mating, and the litter size was also affected by parity. The survival rate was higher among the centric fusion heterozygotes compared to the homozygous animals. It is concluded that the centric fusion polymorphic system is balanced, the higher survival rate among heterozygotes counteracting the lower litter size of these animals.