Split-dose and Liquid-holding Recovery after X-irradiation in Diploid Yeast Saccharomyces Cerevisiae

Summary

Liquid-holding recovery (LHR) and the sparing effect of dose fractionation were investigated with 100 kVp-X-rays in diploid yeast from exponential and stationary phase. Exponential cells showed prompt and complete split-dose recovery. The ability to undergo LHR remained constant during 2·5 hours incubation after the first dose. Stationary-phase cells did not exhibit split-dose recovery (SDR) in a simple way: there was an increase in sensitivity after 3·5 hours followed by a gradual increases with time. It is suggested that stationary cells are starved of an essential co-factor which has to be synthesized de nova.