Molecular cloning and characterization of GABA receptor and GluCl subunits in the western flower thrips, Frankliniella occidentalis.

Abstract To understand the role of target site insensitivity in abamectin resistance in the western flower thrips (WFT), Frankliniella occidentalis (Pergande), cDNAs encoding gamma-aminobutyric acid receptor subunit (FoRdl) and glutamate-gated chloride channel (FoGluCl) were cloned from WFT, and both single nucleotide polymorphisms (SNPs) and mRNA expression levels of FoRdl and FoGluCl were detected in a susceptible strain (ABA-S) and a laboratory selected strain (ABA-R) displaying 45.5-fold resistance to abamectin. Multiple cDNA sequence alignment revealed three alternative splicing variants of FoRdl and two alternative splicing variants of FoGluCl generated by alternative splicing of exon 3. While sequence comparison of FoRdl and FoGluCl in ABA-S and ABA-R strains identified no resistance-associated mutations, the expression level of FoGluCl in ABA-R strain was 2.63-fold higher than that in ABA-S strain. Thus, our preliminary results provide the evidence that the increased mRNA expression of FoGluCl could be an important factor in FoGluCl -mediated target site insensitivity in WFT. Graphical abstract Unlabelled Image Highlights • The insecticide target genes FoRdl and FoGluCl were cloned from Frankliniella occidentalis. • Three variants of FoRdl and two variants of FoGluCl were generated by alternative splicing of exon 3. • The single nucleotide polymorphisms (SNPs) of FoRdl and FoGluCl were detected in abamectin-resistant strain (ABA-R). • mRNA expression levels of FoRdl and FoGluCl were detected in ABA-R and the susceptible strain ABA-S. [ABSTRACT FROM AUTHOR]