IN-VITRO FERTILIZATION RATE OF MOUSE OOCYTES WITH SPERMATOZOA FROM THE F1 OFFSPRING OF MALES IRRADIATED WITH 1.0-GY CS-137 GAMMA-RAYS

Previous studies suggest that the spermatozoa from acutely irradiated male mice exhibit a reduced fertilization rate in vitro with the maxim um decrease occurring for spermatozoa produced 6 weeks after irradiati on (Y. Matsuda et al., Mutation Res. 142 (1985) 59-63). We have found that spermatozoa from unirradiated F-1 males conceived 6 weeks after p aternal F-0 irradiation also exhibit a significantly reduced fertiliza tion rate in vitro. After acute Cs-137 gamma-irradiation yielding an a bsorbed dose of 1.0 Gy, adult CD1 F-0 male mice were mated at weekly i ntervals with unirradiated female CD1 mice. Unirradiated adult males f rom F-1 litters conceived 5 and 6 weeks after paternal F-0 irradiation were allowed to mature. Their epididymal spermatozoa were evaluated f or in vitro fertilization rates using oocytes from unirradiated 8-12-w eek-old CD1 females. The mean fertilization rate for spermatozoa from F-1 males conceived 5 weeks after paternal F-0 irradiation (80.74 +/- 15.74 SD %, n = 5) did not differ significantly from the control ferti lization rate (89.40 +/- 10.94 SD %, n = 8). However, the fertilizatio n rate for spermatozoa from F-1 males conceived 6 weeks after paternal F-0 irradiation (56.14 +/- 21.93 SD %, n = 5) was significantly less than the fertilization rate for control spermatozoa (p < 0.006) or for that of the F-1 males conceived 5 weeks after paternal F-0 irradiatio n (p < 0.04). These data suggest that spermatozoa obtained 6 weeks aft er paternal F-0 irradiation can transmit a decrease in fertilization r ate to the F-1 generation males as well as exhibit decreased fertiliza tion rate themselves when tested directly in vitro. (C) 1997 Elsevier Science B.V.