Cloning and polymorphism analysis of glutamate-gated chloride channel gene of laodelphax striatellus (Hemiptera: Delphacidae)

Abstract

A glutamate-gated chloride channel (GluCl) gene encodes a transmembrane domain protein that is an important target for insecticides. In insects, the GluCl genes of Tribolium castaneum, Apis mellifera, Nasonia vitripennis, Drosophila melanogaster, Musca domestica, Lucilia cuprina, Aedes aegypti, Schistocerca gregaria, Plutella xylostella and Acyrthosiphon pisum were cloned, but not the corresponding gene of Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae), the small brown planthopper. In this study, the complete cDNA sequence of GluCl gene from L. striatellus was cloned and sequenced. The sequence includes 2,112 nucleotides, and the open reading frame ranges from 208 to 1,566 bp. The sequence encoded 452 amino acid residues. Alignment of the amino acid sequences of the GluCls between L. striatellus and other species indicated that the similarity of sequences was in the range of 48%-86%. The purified reverse transcription PCR product of GluCl coding sequence was cloned into a T-vector and then the sequence was analyzed. This analysis revealed polymorphism of GluCl gene among several strains, including a relatively susceptible strain, a fipronil resistant strain and a field strain of L. striatellus. Because the GluCls is an important target receptor, the GluCl gene in L. striatellus is worthy of further investigation.