Drosophila melanogaster Variation

The laboratory selected DDT resistant and control strains 91-R and 91-C, respectively, represent lines that have a common origin, have been kept side-by-side in the laboratory, yet while 91-C received no DDT selection, 91-R received intense DDT selection pressure for over 50 years. Using these resource populations, whole genome re-sequencing data were generated from pools of individuals from the Drosophila strains 91-R and 91-C, and applied to detect chromosome regions putatively affected by prolonged DDT selection. To the authors' knowledge, no selective sweep analysis, across the entire insect genome, has been performed to identify such loci in highly DDT resistant insects, although there has been a study focused on insecticide resistant blow flies (Lucilia cuprina) examining selective sweeps around an individual gene (36) and some additional studies looking at signatures of selection around transposable elements (37, 38). We tested the hypothesis that the expected usual gene suspects for DDT resistance would be detected, as opposed to the alternative that resistance is polygenic with many other genes impacting resistance. Elucidating these genetic and biochemical mechanisms associated with pesticide resistance evolution might lead to improved pest management strategies. Equally important, such information has the potential to further our understanding of how DDT impacts biological processes that are evolutionarily conserved between insects and mammals.