EFFECTS OF CHEMICAL MUTAGENS ON SPERMATOG ENESIS IN MAMMALS - CYTOGENETIC ANALYSIS

It was shown using the micronucleus test and estimating the defects of sperm heads that premeiotic and meiotic mammalian cells are genetical ly very sensitive to Dipin and nitrosomethylurea. In rats, unlike mice , the stem and differentiating spermatogonia with serious chromosomal defects are not eliminated and pass through a ''sieve'' of mitotic and meiotic divisions reaching the stage of round spermatids. Our observa tions suggest long-term preservation Dipin-induced, rather than nitros omethylurea-induced, mutations in the stem cells of both mice and rats .