Recovery from X-ray-induced Sub-lethal Damage inSaccharomyces CerevisiaeCells of Different Ploidy

Abstract

Experiments of dose fractionation have been performed on a polyploid series (from 2n to 4n) of yeast cells, in order to check for the recovery from sub-lethal damage and to investigate whether there is a correlation between kinetics of recovery and ploidy. Cells in a resting state or in log phase of growth were used. The data obtained show that recovery takes place in all the tested strains and display a similar type of kinetics, independently from the degree of ploidy. In the case of resting cells we get a curve describing only the recovery process, while, when growing cells are used, this curve is modified by the concomitant progression of the cells toward division. In this latter case, the value of complete recovery is attained by the three strains in different time intervals, probably related to the specific rates of growth.