THE INDUCTION OF MUTATION IN YEAST BY THERMAL NEUTRONS

Abstract

The efficiency of thermal neutrons in producing mutations from histidine dependence to independence in diploid yeast was compared with that of gamma rays. At equivalent absorbed doses, the yield of mutations was higher with neutron irradiation. In contrast, when % survival was chosen as the basis of comparison, the yield was higher with gamma irradiation. There is evidence that the mutations under study were associated with chromosome aberrations, and the apparent relative mutagenic inefficiency of thermal neutrons is attributed to a reduced survival of mutants under conditions of thermal neutron irradiation.