Effects of in Vitro X-Irradiation on the Survival of Mouse Eggs

Abstract

Unfertilized oviducal eggs, obtained by superovulation of prepuberal C3H mice, were treated in vitro with doses of X-irradiation ranging from 10 to 900 r and transplanted to recipient Cal A females in which fertilization and development occurred. Recipient females were autopsied 17 to 19 days later. Living and dead fetuses from donor and native eggs were identified and counted, and resorption sites were counted. Thirty-eight per cent of control nonirradiated eggs survived and developed to term; in general, per cent survival decreased with increasing doses of irradiation. Death occurred at several developmental stages after irradiation. Only 1% of oocytes receiving lethal doses of irradiation survived longer than the 12th day of gestation; a higher proportion apparently died after implantation but before eye color could be distinguished. Death prior to implantation showed the best correlation with amount of X-ray administered; it increased sharply with increasing dosage of irradiation. The data are represented by the following dosage classification: LD10-20, 10 to 100 r; LD40-50, 200 to 300 r; LD70-90, 400 to 700 r; LD99-99.9, 750 to 900 r.