Functional characterization of CYP9J26, a cytochrome P450 associated with insecticide resistance in the arbovirus vector Aedes albopictus

Aedes albopictus is a primary vector of arboviral diseases such as dengue fever, chikungunya fever, and Zika. The rapid development of insecticide resistance is becoming a major challenge to sustainability of insecticide-based interventions for the control of Ae. albopictus borne arboviral diseases. Understanding the molecular basis of resistance is useful for developing effective insecticide-based control action. Our recent study showed that overexpression of the AalbCYP9J26 gene was associated with insecticide resistance in field Ae. albopictus populations in Beijing, but its contribution to insecticide metabolism and resistance remains unknown. In this study, the metabolic capacity of AalbCYP9J26 towards six insecticides was examined using an enzyme system reconstituted with Escherichia coli-produced AalbCYP9J26 protein and its redox partners (AalbCPR and Aalbb5). The results showed that AalbCYP9J26 was able to metabolize temephos, malathion, propoxur, permethrin, and deltamethrin, while no significant activity against bendiocarb was observed. Moreover, the Drosophila GAL4/UAS transgenic system confirmed that enhanced expression of AalbCYP9J26 conferred increased tolerance to malathion, permethrin, deltamethrin, and propoxur. This study demonstrates that AalbCYP9J26 plays a critical role in insecticide metabolism and resistance, suggesting AalbCYP9J26 may serve as a valuable biomarker for monitoring insecticide resistance and a target for new insecticidal agents.