Functional validation of CYP304A1 associated with haedoxan A detoxification in Aedes albopictus by RNAi and transgenic drosophila

Abstract

BACKGROUND: Insect cytochrome P450 monooxygenases play important roles in the detoxification metabolism of endogenous and exogenous compounds. Haedoxan A (HA) from Phryma leptostachya L. is a highly efficient natural pesticide used to control houseflies and mosquitos. CYP4C21 and CYP304A1 were previously demonstrated to be transcriptionally increased in Aedes albopictus in response to HA exposure, but their involvement in HA metabolism is unknown. RESULTS: Our data showed that CYP304A1 expression levels in A. albopictus were highest in third-instar larvae, and the expression level of CYP4C21 decreased significantly with the growth of instars, with the lowest occurring in the pupal stage. Compared with the control, the silencing of CYP304A1 and CYP4C21 genes by chitosan nanoparticle-mediated RNA interference could deplete 58.2% and 54.0% of the expression of corresponding genes, respectively. The bioassay data showed that knocking down the expression of CYP304A1 increased the mortality of A. albopictus when exposed to HA at LC 30 and LC 50 doses, but did not significantly increase mortality after silencing CYP4C21. Our data demonstrated that CYP304A1, but not CYP4C21, may be involved in HA detoxification. Moreover, the resistance ratio of CYP304A1 overexpressing flies was approximately 2-fold higher than that of the control line. The metabolized product of HA by CYP304A1 needs to be further confirmed by in vitro expression. CONCLUSION: This finding showed that inducibility was not always linked to detoxifying capabilities, and enhanced our understanding of the molecular basis of HA metabolic detoxification in A. albopictus.

Key Contributions of the OverexpressedPlutella xylostellaSigma GlutathioneS-Transferase 1 Gene (PxGSTs1) in the Resistance Evolution to Multiple Insecticides

“…melanogaster carrying PxGSTs1 demonstrated a higher LC 50 to all tested insecticides, compared to the nontransgenic control strains (w1118) (Table ). In previous reports, transferring CYP304A1 from Aedes albopictus to fruit flies found that the fruit flies’ resistance to haedoxan A increased by 2.051-fold . Transferring Cyp6 cm1 of B.…”

“…In previous reports, transferring CYP304A1 from Aedes albopictus to fruit flies found that the fruit flies' resistance to haedoxan A increased by 2.051-fold. 41 Transferring Cyp6 cm1 of B. tabaci to D. melanogaster conferred 2-to 3-fold resistance to neonicotinoid insecticides. 42 These studies all indicated that the increased resistance level after transferring the detoxification enzyme gene confirmed the metabolic function of the detoxification enzyme.…”

Unveiling candidate genes for metabolic resistance to malathion in Aedes albopictus through RNA sequencing-based transcriptome profiling

“…An indication of its function is provided by a recent study on Ae . albopictus larvae suggesting that it is induced by haedoxan A and participates in haedoxan A detoxification [ 61 ]. Further studies are needed to elucidate mechanisms of gene regulation for the cytochrome P450 system.…”

Transcriptomic Analysis Reveals the Detoxification Mechanism of Chilo suppressalis in Response to the Novel Pesticide Cyproflanilide

“…In addition to the effect of exogenous substances on insect reproduction and development, the detoxification and metabolism of exogenous substances by pests have been extensively studied [ 28 , 29 , 30 , 31 ]. In this study, 28 DEGs were primarily enriched in the “drug metabolism- other enzymes”, “glutathione metabolism” and “Metabolism of xenobiotics by cytochrome P450” pathways.…”