INDUCTION OF SPECIFIC-LOCUS AND DOMINANT LETHAL MUTATIONS IN MALE-MICE BY N-PROPYL AND ISOPROPYL METHANESULFONATE

n-Propyl methanesulfonate (nPMS) and isopropyl methanesulfonate (iPMS) induce dominant lethal and specific-locus mutations in male mice. The responses of the various spermatogenic stages to the induction of mut ations differ markedly for nPMS and iPMS. Independent of the effective dose range the induction of dominant lethal mutations by nPMS is limi ted to spermatozoa and spermatids. In contrast, the induction of domin ant lethal mutations by iPMS is dose dependent: a dose of 20 mg iPMS/k g body weight (bw) is active only in spermatocytes, while a dose of 10 0 mg/kg bw induces dominant lethal mutations in all postspermatogonial germ cell stages. One other striking difference in the biological eff ectiveness of both compounds is that iPMS induces a sterile phase in s tem-cell spermatogonia, whereas nPMS treated males even at the highest dose are fully fertile.