Structural Variants and Selective Sweep Foci Contribute to Insecticide Resistance in the Genetic Reference Panel.

Patterns of nucleotide polymorphism within populations of suggest that insecticides have been the selective agents driving the strongest recent bouts of positive selection. However, there is a need to explicitly link selective sweeps to the particular insecticide phenotypes that could plausibly account for the drastic selective responses that are observed in these non-target insects. Here, we screen the Drosophila Genetic Reference Panel with two common insecticides; malathion (an organophosphate) and permethrin (a pyrethroid). Genome-wide association studies map survival on malathion to two of the largest sweeps in the genome; and Malathion survivorship also correlates with lines which have high levels of , and transcript abundance. Permethrin phenotypes map to the largest cluster of P450 genes in the Drosophila genome, however in contrast to a selective sweep driven by insecticide use, the derived allele seems to be associated with susceptibility. These results underscore previous findings that highlight the importance of structural variation to insecticide phenotypes: exhibits copy number variation and transposable element insertions, is tandemly duplicated, the loci are associated with a transposable element insertion, and a deletion is associated with susceptibility.