Influence of Linear Energy Transfer and Oxygen Tension on the Effectiveness of Ionizing Radiations for Induction of Mutations and Lethality in Saccharomyces cerevisiae

Abstract
The effectiveness of heavy ions and X-rays with LET values covering the range 20 to 6000 Mev gm-1cm2 for inducing mutations and lethality in diploid yeast was studied. For all effects, maximum efficiency was observed in the LET range corresponding to boron or carbon nuclei. The oxygen effect decreased with increases in LET, although for one of the reversions an oxygen effect of 2 was found for neon ions. The survival curves remained sigmoid even for the most densely ionizing radiations. For a given amount of inactivation, the probability of recovering mutants among the survivors decreased with increasing LET.