UV IRRADIATION OF WILD TYPE AND RADIATION-SENSITIVE MUTANTS OF THE NEMATODE Caenorhabditis elegans: FERTILITIES, SURVIVAL, AND PARENTAL EFFECTS

Abstract— Survival after UV irradiation was examined in wild type and four radiation-sensitive ( rad ) mutants of Caenorhabditis elegans . Synchronous populations were employed to assess radiation sensitivities at different developmental stages. In addition, the effects of irradiation on male and hermaphrodite fertilities were measured. Wild-type sensitivity was maximal early in embryogenesis. Different age-dependent patterns of radiation sensitivity were obtained with the rad mutants. The effects of parental genotype were also tested. A parental wild-type allele was capable of quickly elevating the radiation resistance of embryos derived from homozygous rad hermaphrodites. In a second parental-effect test, homozygous rad embryos displayed greater radiation resistance when derived from heterozygous rather than homozygous hermaphrodites. The results indicate that radiation sensitivity in this metazoan is determined by complex interactions of gene products.