Abstract: 【Aim】 This study aims to clone the coding sequence of ATP synthase B subunit gene, to perform bioinformatics analysis for the coding sequence and to characterize its association with deltamethrin resistance in Culex pipiens pallens. 【Methods】 The coding sequence of ATP synthase B subunit gene in C. pipiens pallens was amplified by PCR method. The physical-chemical properties and functional characteristics of the encoded protein were predicted by employing the web-based bioinformatics analysis. The expression of ATP synthase B subunit gene was compared between the deltamethrin-susceptible and-resistant strains selected in the laboratory by quantitative real-time PCR method, and between the deltamethrin-susceptible and -resistant individuals of the field populations for further verification. 【Results】 The coding sequence of ATP synthase B subunit gene (GenBank accession no.: KY783434) was cloned, which contains 717 nucleotides encoding 238 amino acids. Bioinformatics analysis showed that its encoded protein has a theoretical relative molecular weight of 26.96 kD and the isoelectric point value of 8.97 approximately. It was predicted that ATP synthase B subunit contains a structural domain (amino acids 70-231) of ATP-synthase_B, but lacks signal peptide and transmembrane domain. Quantitative real-time PCR results revealed that the expression level of ATP synthase B subunit gene was up-regulated in the deltamethrin-resistant strain as compared with that in the deltamethrin-susceptible strain selected in the laboratory, and also in the deltamethrin-resistant individuals of the field populations as compared with that in the deltamethrin-susceptible individuals of the field populations. 【Conclusion】 This study obtained the coding sequence of ATP synthase B subunit gene, performed bioinformatics analysis for the sequence, and confirmed its overexpression in the deltamethrin-resistant individuals, providing the basis for further studying its roles in insecticide resistance.

Key words: Culex pipiens pallens, ATP synthase B subunit, insecticide resistance, deltamethrin, bioinformatics