Stem-spermatogonial survival and incidence of reciprocal translocations in the gamma-irradiated boar.
To assess the effects of gamma-radiation on stem-cell survival and incidence of reciprocal translocations, boar testes were irradiated with 100, 200, or 400 rad. Stem-cell survival was markedly affected by 100 rad (51% of control) and reduced to 34% of control by 400 rad. Production of differentiating spermatogonia was all but completely interrupted by 200 rad and spermatogonial renewal was incomplete at 12 weeks. From the state of the seminiferous epithelium at 12 weeks, estimates of the percentage of permanent impairment of sperm-producing capacity ranged from 20 +/- 6 (100 rad) to 67 +/- 10 (400 rad). Incidence of translocations peaked at 200 rad and the number occurring at 100 and 400 rad was similar. Kinetics of porcine spermatogonial renewal differs considerably from those of the rodent and, relative to the rodent, this may account for the boar's higher sensitivity to stem-cell killing and lower sensitivity to translocations.
D000818:Animals; D002470:Cell Survival / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D008297:Male; D008540:Meiosis / Q000528:radiation effects; D013076:Sperm Count; D013091:Spermatogenesis / Q000528:radiation effects*; D013093:Spermatogonia / Q000166:cytology* / Q000648:ultrastructure; D013094:Spermatozoa / Q000166:cytology*; D013552:Swine; D014178:Translocation, Genetic / Q000528:radiation effects*; D014916:Whole-Body Irradiation