Molecular cloning and sequence analysis of chitinase cDNA from Mamestra brassicae

Key Words：Mamestra brassicae， chitinase， molecular cloning， sequence analysis

Abstract：     Insect chitinase has great potential in biological control of insect pests. Total RNA was isolated from the whole body of Mamestra brassicae L. at prepupal stage. The cDNA sequence was cloned by RTPCR and rapid amplification of cDNA ends was conducted. The cDNA of 2 826 base pairs in length contained an open reading frame of 1 689 base pairs coding for a polypeptide of 562 amino acid residues with a predicted molecular weight of 62.6 kDa and pI 5.30. The deduced amino acid sequence of M. brassicae chitinase was predicted using the software Prosite, which indicated that it has two putative N-glycosylation sites and twenty two putative O-glycosylation sites. The predicted protein shared extensive similarites with those from other insects, expecially the lepidopteran insects. The cDNA sequence has been deposited in GenBank with accession No. FJ436415.