Genotoxicity of the anti-juvenile hormone agent precocene II as revealed by the Drosophila wing spot test

The anti-juvenile hormone agent, precocene II, designated as a prototype of potential fourth-generation insecticides, was subjected to genotoxicity screening by means of the somatic mutation and recombination test in Drosophila melanogaster. Larvae heterozygous for recessive wing trichome mutations, mwh and flr3, were exposed to sublethal concentrations of precocene II, and wings of emerged adult females were inspected for the presence of phenotypically mutant mosaic spots. The compound significantly increased the frequency of mosaic spots in mwh/flr3 wings, but revealed only a slight effect in mwh/TM2 wings. The results suggest that the main sources of genotoxic activity of precocene II are due to chromosome-breakage phenomena resulting from mitotic recombination. The possible mechanism of this effect is discussed.