Abstract
Mitomycin C was injected into the abdomen of male flies of the y2 sc1 waG strain of Drosophila melanogaster. They were mated with females bearing attached-X chromosomes, and the male offspring (F1) were analysed for the appearance of mutations in the X chromosome. We observed y+ and sc+ reversions induced either by excision of mdg4 (gypsy) with retention of one long terminal repeat (LTR) or by insertion of a foreign sequence into mdg4, partial reversion of the waG mutation, waG----waGd, and unstable f mutations. The overall mutation frequency was considerably higher than in control flies of the y2 sc1 waG strain. Possible mechanisms of genomic rearrangements induced by Mitomycin C, in particular the role of homologous recombination, are discussed.
