title: Specific locus mutation rates after repeated small radiation doses to mouse oocytes.
abstract: When female mice were given a dose of 20 X 20 rad X-rays, the specific locus mutation rate among offspring conceived up to 7 weeks after the end of treatment was 1/39887 or 0.18-10(-7)/rad/locus, whereas when the same total dose of 200 rad was given in a single exposure the mutation rate was 9/34813 or 1.85-10(-7)/rad/locus. The lower mutation rate after the 20 X 10 rad dose was obtained whether the total or 200 rad was given over a period of 5 days or 4 weeks, and if only young conceived in the first 20 days, rather than 7 weeks, were considered. It is suggested that each 10 rad fraction had the same small effect, and hence that these results confirm and extend RUSSELL's previous finding that the dose-response relationship for specific locus muations in females is curved.
mesh_terms: D000818:Animals; D004307:Dose-Response Relationship, Radiation; D005260:Female; D051379:Mice; D009154:Mutation; D009865:Oocytes / Q000528:radiation effects*; D010063:Ovum / Q000528:radiation effects*; D011831:Radiation Genetics; D014965:X-Rays