Mitotic recombination in continuously gamma-irradiated diploid yeast.

A diploid yeast strain heterozygous at the canavanine locus was subjected to long-term gamma exposure in continuous chemostat cultures. Radiation induces canavanine resistance presumably by mitotic recombination. The efficiency of this process increased with lower dose rate. Experiments using a split-dose protocol showed that radiation possibly induces a recombinogenic activity.