Radiation-induced chromosome aberrations in mouse spermatocytes and oocytes.

ICR/Swiss males and females were exposed to 300 R whole-body gamma irradiation. The frequency of aberrations in metaphase I chromosomes recovered from oocytes cultured in vitro was compared with those recovered from spermatocytes irradiated in pachytene and diplotene. The ability of oocytes collected 1 day postirradiation to mature in vitro was not affected, but significantly fewer oocytes cultured 5 days after irradiation matured. The frequency of aberrations in oocytes did not differ from spermatocytes irradiated during diplotene, but significantly more chromosome aberrations were found when pachytene spermatocytes were irradiated. Some variation in the relative frequencies of aberrations was also observed.