INTERSTRAIN DIFFERENCES IN THE PARAMETERS OF SPERMATOGENESIS IN INBRED MICE.

The aim of the present work was a comparative study of basic parameters of spermatogenesis in mice of inbred PT (n=99) and CBA/Lac (n=81) strains, starting with the puberal period of development until Day 80. The number of spermatozoa was measured in the caudal portions of both epididymides (epididymal reserve), morphological characteristics and spermatozoa motility were evaluated, and body, testes and epididymal weight was determined. Starting from puberty and thereafter, it was found that CBA/Lac males as compared with RT mice had lower testicular mass and epididymal spermatozoa number. However, spermatozoa functional capacity of CBA/Lac males was higher as compared to that of PT mice, since starting with the puberal period, they were characterized by a lower frequency of abnormal forms, and in the post-puberal period — by higher relative concentrations of motile spermatozoa. Thus, in the males of laboratory mice studied, the interstrain differences in the key parameters of spermatogenesis related to fertility, began to emerge in the puberal period, and their interstrain variability may have a compensatory character.