Split-dose recovery is due to the repair of DNA double-strand breaks.
DNA double-strand breaks are the molecular lesions the repair of which leads to the reappearance of the shoulder observed in split-dose experiments. This conclusion is based on results obtained with the help of a diploid yeast mutant rad 54-3 which is temperature-conditional for the repair of DNA double-strand breaks. Two repair steps must be met to yield the reappearance of the shoulder on a split-dose survival curve: the repair of double-strand breaks during the interval between two doses and on the nutrient agar plate after the second dose. In yeast lethality may be attributable to either an unrepaired double-strand break (i.e. a double-strand break is a potentially lethal lesion) or to the interaction of two double-strand breaks (misrepair of double-strand breaks). Evidence is presented that the two cellular phenomena of liquid holding recovery (repair of potentially lethal damage) and of split-dose recovery (repair of sublethal damage) are based on the repair of the same molecular lesion, the DNA double-strand break.
D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D004260:DNA Repair; D004271:DNA, Fungal / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004583:Electrons; D009154:Mutation; D011831:Radiation Genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics
D004271:DNA, Fungal