Identifying genomic changes associated with insecticide resistance in the dengue mosquito Aedes aegypti by deep targeted sequencing. Targeted DNA-seq to study pyrethroid resistance in Aedes aegypti

Mosquitoes represent a major threat by transmitting severe human diseases such as dengue. Controlling mosquito populations with insecticides remains the first line of defense for limiting outbreaks. The efficacy of pyrethroid insecticides mainly used against mosquitoes is now threatened by resistance mechanisms developed by mosquitoes. Resistance management currently suffers from the limited understanding of resistance mechanisms. In this context, the aim of the present study was to identify DNA markers of deltamethrin resistance in the dengue vector mosquito Aedes aegypti using target enrichment technology followed by high-throughput DNA sequencing. Deltamethrin-susceptible (S samples) and -resistant populations (R samples) were collected from various geographical areas. For each resistant population, most resistant individuals (R+ phenotype) were segregated from susceptible individuals (R- phenotype) according to their survival to deltamethrin exposure at the adult stage. Genomic DNA was extracted from pools of 130 adult female mosquitoes for each populations/phenotype. The exon capture technology (Agilent Sureselect) was used to capture the coding sequence and the promoter sequence (1 kb upstream) of more than 760 genes belonging to protein families potentially involved in insecticide resistance. Capture libraries were sequenced on a genome analyzer II (illumine) as paired reads of 76 bp.