NYD-OP7/PLC regulatory signaling pathway regulates deltamethrin resistance in Culex pipiens pallens (Diptera: Culicidae)

BACKGROUND: Investigation of insecticide resistance mechanisms is considered a vital first step towards the creation of effective strategies to control resistant mosquitoes and manage mosquito-borne diseases. Our previous study revealed that NYD-OP7 may be associated with deltamethrin resistance in Culex pipiens pallen. However, the precise function of NYD-OP7 in deltamethrin resistance is still unclear. In this study, we investigated the role of NYD-OP7 in the molecular mechanisms underlying pyrethroid resistance. RESULTS: Knockdown of NYD-OP7 not only increased the susceptibility of the mosquitoes to deltamethrin in vivo but also simultaneously repressed both expression and enzyme activity of its downstream effector molecule, phospholipase C (PLC) and expression of several insecticide resistance-related P450 genes. Knockdown of PLC also sensitized the mosquitoes to deltamethrin and reduced the expression of the P450 genes. CONCLUSIONS: Our results revealed that NYD-OP7 and its downstream effector PLC contribute to deltamethrin resistance by regulating the expression of P450s in Cx. pipiens pallens. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13071-018-3011-5) contains supplementary material, which is available to authorized users.