Cytogenetic analysis of translocations induced by the chemical mutagen thio TEPA in spermatids of male mice.

Cytogenetic analysis of meiotic cells at diakinesis/metaphase I was carried out in 36 reciprocal translocation heterozygotes. Translocations were induced in late spermatids of C57BL/6 male mice with 1:25 mg/kg body weight of thioTEPA. The prevalent types of multivalent configuration were Ring IV in 15F1 males, chain IV in 20 males, and one male showed the same proportion of cells with chains and rings. The conclusion can be made that an intensive mutation process with may induce as much as 30% heterozygous translocation males in characterized by a random distribution of breaks along the chromosome.