Transcriptional response of susceptible insects after insecticide exposure

The physiological impact of insecticide exposure on susceptible insect populations is not fully understood. We investigated this question by measuring the transcriptional response of susceptible insects which were challenged with an insecticide. Female flies of the susceptible Drosophila melanogaster line Canton-S were exposed to low concentrations (LC₅-LC₂₀) of six commonly used insecticides for 24 hours, and surviving flies were collected for RNA extraction and sequencing. The number of genes significantly up- or down-regulated after exposure range from one to thirty-nine depending on the insecticide. There is also very little coordinated response to insecticides, as less than ten significant genes are shared by three or more insecticides. Our results indicate that exposure to insecticides in susceptible D. melanogaster does not generate a broad transcriptional response. The significance of these results, relative to our understanding of how low levels of insecticides in the environment alter gene expression, will be discussed.