Sterility in mutant (tLx/tLy) male mice. I. A morphological study of spermiogenesis.

The results from a comparative ultrastructural study of spermiogenesis in 6-, 10-, 14- and 17-month-old sterile t6/tw32, and fertile T/t6, T/tw32 and BALB/c, mice are reported. The studies show that all of the males contained the same types of defective spermatids and that defects were not limited to specific spermatid stages. Younger males had fewer abnormal spermatids than older males of the same genotype and at each age the BALB/c and t6/tw32 males appeared to contain more abnormal spermatids than the other males. No unique spermatid defect or increased frequency of a specific defect was found which can be correlated with infertility of the t6/tw32 males.