Global, asynchronous sweeps at multiple resistance genes in Aedes mosquitoes

Insecticide-based management of the globally-invasive mosquito Aedes aegypti has led to the evolution of insecticide resistance across populations. Resistance can have complex genetic architectures which can be revealed using genomic data with sufficient geographical coverage. Here we report global sweeps on two chromosomes containing resistance genes. Sweeps at the voltage-sensitive sodium channel gene (VSSC) on chromosome 3 correspond to three substitutions in Ae. aegypti, including two at the same nucleotide position (F1534C). In Ae. aegypti, we identify a second swept region on chromosome 2, containing 15 glutathione S-transferase (GST) epsilon genes with significant copy number variation across populations and where three distinct haplotypes have swept through the Indo-Pacific region, the Americas, and Australia. Local patterns indicate VSSC and GST backgrounds swept asynchronously. These findings highlight the global significance of GST genes and open new avenues of research into their evolution and function.