Global changes in alternative splicing are associated with insecticide response and resistance

Alternative splicing (AS) promotes phenotypic plasticity to adverse conditions by altering transcripts involved in stress adaptation. However, whether changes in AS occur transcriptome-wide or in only a few key genes is unclear. Agricultural insect pests are regularly exposed to xenobiotic stress from insecticide applications and thus develop resistance. We show that the pest Drosophila suzukii, resistant to multiple insecticides, exhibits increased global AS events compared to susceptible flies. Alternatively spliced genes are enriched in multiple processes including stress response and insecticide resistance, suggesting AS is a mechanism underlying insecticide resistance development. Furthermore, sublethal insecticide exposure promotes AS events even in the absence of substantial differential gene expression. This study provides insights into the role of AS in enabling insects to diversify genome function to survive acute insecticide treatment and to develop xenobiotic resistance.