Molecular characterization of glutamate-gated chloride channel and its possible roles in development and abamectin susceptibility in the rice stem borer, Chilo suppressalis

Abstract

Glutamate-gated chloride channels (GluCls) mediate fast inhibitory neurotransmission in invertebrate nervous systems, and are of considerable interest in insecticide discovery. The full length cDNA encoding CsGluCl was cloned from the rice stem borer Chilo suppressalis (Walker). Multiple cDNA sequence alignment revealed three variants of CsGluCl generated by alternative splicing of exon 3 and exon 9. While all the transcripts were predominantly expressed in both nerve cord and brain, the expression patterns of these three variants differed among other tissues and developmental stages. Specifically, the expression level of CsGluCl C in cuticle was similar to that in nerve cord and brain, and was the predominant variant in late pupae and early adult stages. Both injection and oral delivery of dsGluCl significantly reduced the mRNA level of CsGluCl. Increased susceptibility to abamectin and reduced larvae growth and pupation rate were observed in dsGluCl-treated larvae. Thus, our results provide the evidence that in addition to act as the target of abamectin, GluCls also play important physiological roles in the development of insects.

Keywords: Abamectin; Alternative splicing; GluCl; Larvae development; RNA interference; mRNA expression.