Fig. 1.

Screening candidate genes via quantitative real-time PCR. (A) The relative expression levels of 11 genes in adult female mosquitoes of the DS and the DR1 strains. Five of the 11 genes (chymotrypsin-2, dimethylaniline monooxygenase, carboxylesterase, venom allergen 5, and phenoloxidase subunit 1 precursor) were significantly overexpressed in the DR1 strain compared with the DS strain. (B) The relative expression levels of five genes in adult female mosquitoes of the susceptible and resistant strains of two field populations (Shanghe and Gudao). The relative expression levels of the venom allergen 5 were 60.58- and 7.34-fold higher in the resistant strains than the susceptible strains. (C) The relative expression levels of venom allergen 5 in adult female mosquitoes with different levels of deltamethrin resistance (DS, DR1, DR2, and DR3). The LC₅₀ of the DS, DR1, DR2, and DR3 strains were 0.03, 0.85, 3.7, and 7.0 mg/liter, respectively. The venom allergen 5 expression levels were 3.3-, 4.7-, and 29.7-fold higher in the DR1, DR2, and DR3 strains, respectively, than the DS strain. Figures show the mean ± SD of three independent experiments. *P < 0.05, **P < 0.01 compared with the DS strain.