Abstract
Our previous study has shown that the inheritance of dimefluthrin resistance in Ae. albopictus is codominant inherited completely maternally by reciprocal crosses. In this study, we found that NADH dehydrogenase subunit Ⅳ (ND4) gene was overexpressed in the resistant strain. Subsequently, when RNAi technology was used to suppress the ND4 gene expression in the resistant strain, the resistance of Ae. albopictus also decreased significantly. Meanwhile, it was found that the activities of mitochondrial respiratory chain complex and Na+, K+-ATPase in the resistant strain were higher than in the susceptible strain, but the ATP content was lower. However, the activities of complex Ⅰ, V and Na+, K+-ATPase in the resistant strain decreased significantly after interference, while the ATP content increased significantly. Therefore, we demonstrated that ND4 gene was involved in the resistance of Ae. albopictus to dimefluthrin, and ND4 was related to the resistance by affecting the respiratory chain system. In addition, we evaluated the fitness cost of female mosquitoes of both strains and found that the resistant strain was diapause and shortened lifespan, and speculated the fitness cost of dimefluthrin-resistant Ae. albopictus was due to the uneven energy consumption in the body.