Abstract
Cytogenetic studies of spermatogenic radiosensitivity were performed by analysis of the first cleavage metaphase and by dominant lethal tests in mice. Male mice were subjected to acute X-irradiation (500rad) and each male was then serially mated with two virgin females per week for six weeks. Chromosome aberrations were scored at the paternal chromosome sets in the first cleavage mataphases after fertilization. Spermatids were nearly twice as sensitive as spermatozoa to the induction of chromosome aberrations and dominant lethals, and chromosome-type aberrations were mainly induced. The profile of stage-specific chromosome aberrations induced by X-rays in male germ cells was different from that induced by chemical agents.
