Abstract: 【Aim】CYP6G1 is one of the important P450 enzymes in Drosophila melanogaster, and has a wide substrate spectrum. In addition to mediating DDT resistance in D. melanogaster, CYP6G1 is also implicated in its resistance to neonicotinoid and carbamate insecticides. However, there are still some research gaps between the metabolic function of CYP6G1 and insecticide resistance in D. melanogaster. 【Methods】In this study, the cytochrome P450 enzyme CYP6G1 was expressed functionally by the Bac-to-Bac insect baculovirus expression system, and the metabolism of thicloprid and thiamethoxam by the recombinant CYP6G1 in vitro was analyzed by ultra-performance liquid chromatography (UPLC) and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with imidacloprid as a positive control. 【Results】After 2-h incubation, the recombinant CYP6G1 metabolized 17.6%±7.1% of imidacloprid and 4.2%±2.3% of thiacloprid, respectively, by participating in the hydroxylation reaction. In addition, the recombinant CYP6G1 could promote the conversion of thiamethoxam to clothianidin and reduced the thiamethoxam content by 5.8%±2.1%. 【Conclusion】The results of this study provide a theoretical basis for the study on the structure and function of CYP6G1.

Key words: Drosophila melanogaster, cytochrome P450, CYP6G1, Bac-to-Bac insect baculovirus expression system, function research, insecticide, in vitro metabolism