Adaptive response to alkylating agents in the Drosophila sex-linked recessive lethal assay

The adaptive response to alkylating agents was studied in Drosophila assays under various treatment procedures. Pre-treatment of males as well as treatment of females with low doses of EMS (0.05-0.1 mM) did not affect sex-linked recessive lethal (SLRL) rates induced by high doses of this mutagen (10 mM, various feeding duration) in mature sperm cells. Pre-treatment of males with a low dose of MMS (0.1 mM) enhanced mutagenesis induced by the high dose of EMS (10 mM) at different stages of spermatogenesis, the observed effects exceeding the additive action of both mutagens. On the contrary, larval pre-treatment with the adaptive dose of EMS (0.05 mM) resulted in resistance of their germ cells to higher doses of EMS (1 mm). Specifically, offspring production increased while dominant lethality in F-1 as well SLRL frequency in F-2 was significantly reduced as compared with the effects of larval exposure to the challenge dose. Under the conditions tested, the adaptive response of germ cells to alkylating agents was demonstrated in larvae, but not in adult flies. (C) 2002 Elsevier Science B.V. All rights reserved.