PBT selected ten-minute paper 2: G protein-coupled receptors mediated insecticide resistance in mosquitoes

G protein-coupled receptors (GPCRs) regulate signal transduction pathways and play diverse and pivotal roles in physiological pathways in insects, and have thus been proposed as potential targets for new insecticides. The previous studies have shown the importance of GPCRs in insecticide resistance. However, the precise function of GPCRs and their regulatory pathway in insecticide resistance remain unclear. Our current study explored, for the first time, the regulatory function of GPCRs and GPCR-related genes in the insecticide resistance of mosquitoes, Culex quinquefasciatus. Four GPCR-related genes were identified that were up-regulated in the larvae and adults of 2 highly resistant strains, HAmCq^G8 and MAmCq^G6, after a relative expression screening of 115 GPCRs between resistant and susceptible mosquitoes. Silencing the expression of these up-regulated GPCR-related genes in resistant HAmCq^G8 and MAmCq^G6 strains using RNAi revealed decreases in the levels of resistance to permethrin through the repressed expression of 4 insecticide resistance-related cytochrome P450 genes. This study demonstrates the potential role of GPCR-related genes in insecticide resistance and suggests new strategies for controlling insects, especially resistant strains.