Summary
The effects of visible light post-treatment on the spectrum and frequencies of γ-ray-induced mutations at five specific loci and of macrodeletions of the X chromosome in post-meiotic male germ cells in mutant c(3)G17 of Drosophila melanogaster were studied. It was found that post-treatment by light decreased the yield of chromosome rearrangements to the extent of 1·5 to 2 times, but not that of point mutations.