Cloning and expression pattern of chitin synthase (CHS) gene in epidermis of Ectropis obliqua Prout

Abstract

Ectropis obliqua Prout is a major pest in tea fields. Chitin synthase (CHS) plays an important role in biosynthesis of chitin and growth of the pest. A cDNA sequence encoding the CHS and its expression pattern during development of E.obliqua was investigated. The CHS cDNA sequence was 5496 bp nucleotides, with an open reading frame of 4692 bp encoding a protein of 1563 amino acids. It belonged to CHS-A member of CHS gene family. Alternative splice was found in the CHS-A cDNA and the alternatively spliced fragments were 177 bp and shared 65% identity with each other at the nucleotide level. The CHS-A expression was the strongest in the third and fourth instar larvae, during which the growth rate of E. obliqua larvae was the rapidest. Catalysis model of CHS-A enzyme in E. obliqua was also hypothesized according to the specific motifs and topological structure prediction of the protein. This study provided an important information for further research on development of RNA interference (RNAi) technology to control E. obliqua.

Keywords: Ectropis oblique, tea pest, chitin synthase, gene cloning, RNAi, biological control

African Journal of Biotechnology Vol. 9(33), pp. 5297-5308, 16 August, 2010