title: Somatic damage to the X chromosome of the nematode Caenorhabditis elegans induced by gamma radiation.
abstract: Wild-type male embryos and young larvae of the nematode Caenorhabditis elegans were more sensitive than wild-type hermaphrodites to inactivation by gamma rays; wild-type males have one X chromosome per cell (XO), whereas wild-type hermaphrodites have two (XX). Furthermore, after transformation into fertile hermaphrodites by a her-1 mutation, XO animals were more radiosensitive than XX her-1 animals; and XX animals transformed into fertile males by a tra-1 mutation did not show increased radiosensitivity. It is concluded that wild-type males are more radiosensitive than wild-type hermaphrodites because they have one X chromosome rather than two, and the predominant mode of inactivation of XO animals involves damage to the single X chromosome. No sex-specific differences in survival were observed after UV irradiation.
mesh_terms: D000818:Animals; D002107:Caenorhabditis / Q000235:genetics* / Q000528:radiation effects; D012734:Disorders of Sex Development / Q000235:genetics; D004307:Dose-Response Relationship, Radiation; D004330:Drosophila; D005260:Female; D005720:Gamma Rays; D008297:Male; D009154:Mutation; D012730:Sex Chromosomes / Q000528:radiation effects*; D014466:Ultraviolet Rays; D014960:X Chromosome / Q000528:radiation effects*