[Survival of diploid yeasts after gamma irradiation: genetic control of the maturation effect].

A study was made of the influence of rad mutation, leading to radiosensitivity increase, on the effect of additional growth in diploid Saccharomyces cerevisiae yeast exposed to gamma-radiation. The most radiosensitive mutants of this series, rad52/rad52 and rad54/rad54, did not virtually vary from the wild type cells in the value of the additional growth effect. Some other mutants, for instance, rad53/rad53 and rad55/rad55, exhibited a significantly lesser effect of additional growth. It was shown that the effect of additional growth did not depend upon the rate of rapid and slow postirradiation recovery of the wild type cells. The results of the studies prompt the conclusion that the processes responsible for the additional growth effect and those responsible for recovery of cells from radiation damages are mutually independent.