Functional diversity of voltage‐gated sodium channel in Drosophila suzukii (Matsumura)

Abstract

AbstractBACKGROUNDThe larvae of Drosophila suzukii Matsumura feed directly inside the fruit, causing catastrophic damage to orchards. The misuse of pyrethroid insecticides during the control period has led to increasing resistance of D. suzukii to pyrethroids acting on the voltage‐gated sodium channel (VGSC).RESULTSIn this study, the sodium channel of D. suzukii was cloned (DsNav5 GenBank number: OQ871532). The results of multiple‐sequence alignment showed that the homology of sodium channel between D. suzukii and Drosophila melanogaster was as high as 95.3%. Analysis of transcripts from 62 variants of D. suzukii VGSC revealed a total of six alternative splicing sites (exons u, j, a, b, e, and h) and 33 RNA editing. Exons j, a, b, e, and h are conserved in D. melanogaster and other insects, whereas exon u has never been reported before. The number of A‐to‐I was distinctly more than that of U‐to‐C for RNA editing. All D. suzukii VGSC variants were expressed in Xenopus oocytes, but only one (type 5) was able to produce robust currents and nine produce weak currents. DsNav5 with TipE of D. melanogaster co‐expresses current better than its own TipE. Subsequently, tetrodotoxin was verified to be a blocker of VGSC, and the gating properties of DsNav5 were investigated.CONCLUSIONThese findings proved that the VGSC of D. suzukii has not only the basic gating properties, but also the diversity of gating properties. This study also laid a foundation for the study of pyrethroid resistance mechanism of VGSC in D. suzukii. © 2023 Society of Chemical Industry.