Repair of DNA double-strand breaks in irradiated yeast cells under nongrowth conditions.

Abstract

We show that in diploid yeast radiation-induced DNA double-strand breaks can be repaired under nongrowth conditions at 30/sup 0/C and that liquid holding recovery of colony-forming ability is accompanied by a decrease in the number of double-strand breaks per cell. The kinetics of double-strand break repair under nongrowth conditions depend on the dose applied. For the highest dose used (2400 Gy) repair is completed within about 48 h. We have verified that double-strand breaks which remain unrepaired after 48 h are irreparable under nongrowth conditions. The linear relationship between the initial number of double-strand breaks and dose is converted into a quadratic function of irreparable double-strand breaks with and dose during liquid holding treatment of cells.