cDNA cloning, sequence analysis and expression of JHE gene in Heliothis viriplaca
Author of the article:ZHANG Huan** GUO Bo-Zhi FAN Dong ***
Author's Workplace：Agronomy College, Northeast Agricultural University, Harbin 150030, China
Key Words： Heliothis viriplaca, Juvenile hormone esterase, cloning, sequence analysis, expression
Abstract：[Objectives] To investigate Juvenile hormone esterase (JHE) cDNA sequence and function in Heliothis viriplaca. [Methods] Total RNA was isolated from H. viriplaca and the JHE cDNA sequence was cloned by RT-PCR and rapid amplification of cDNA ends(RACE). A full-length cDNA sequence encoding JHE was obtained and designated as Hvjhe (GenBank accession number: JQ901384. [Results] The cDNA sequence, 3 106 base pairs in length, contained an open reading frame of 1 746 base pairs coding for a polypeptide of 581 amino acid residues with a predicted molecular weight of 63.9 ku and pI 5.11. The Hvjhe sequence contained five specific conserved motifs identified in JHEs of other insect species. The deduced amino acid sequence of Hvjhe shared 83% and 82% identity with homologues in H. virescens and Helicoverpa armigera, respectively. Transcript analysis on the Hvjhe sequence during various developmental stages and in different tissues was determined by qRT-PCR. The results of qRT-PCR revealed that Hvjhe mRNA was expressed at a low level in the feeding, pupal and adult stages, but at a high level in the prepupal stage. The Hvjhe transcript was more highly expressed in the fat body and midgut than in other tissues. SDS-PAGE and Western-blot results revealed that Hvjhe was expressed in E. coli. The molecular weight of expressed protein was consistent with the predicted molecular weight of Hvjhe. [Conclusion] The results indicate that a novel juvenile hormone esterase cDNA sequence was successfully obtained.