抄録
When male Bombyx mori L. was irradiated with 3kR of gamma-rays as 5-day-old- 5th instar larvae and crossed with unirradiated females, approximately 69% of the fertilized eggs hatched. When F1 males from this treated line were crossed with normal females, the eggs were nearly sterile. Eggs from F1 females showed reduced hatchability. In the F2 generation, fertilities of both males and females were normal, though egg hatchability was somewhat reduced. When males were irradiated as pupae, their progeny inherited less sterility than those from males irradiated as 5th instar larvae. No abnormalities were found in spermatogonial proliferation of F1 males, but chromosome aberrations were frequently observed at meiotic metaphase. The majority of such germ cells became functionless sperms in subsequent spermiogenesis. On the basis of these results, a mechanism for inherited sterility is discussed.
