Cloning, sequence analysis and mRNA expression levels of the antennal carboxylesterase gene HaCXE6 from Helicoverpa armigera
Author of the article:JI JiChaoWANG LiShaZHAO ManLI WeiZhengYUAN GuoHuiLUO MeiHaoGUO XianRu
Author's Workplace：College of Plant Protection, Henan Agricultural University, Zhengzhou450002, China
Key Words：Helicoverpa armigera antennal carboxylesterese, gene clone, qPCR, function analysis
Abstract：To study the physiological functions of carboxylesterase ( COE ) in Helicoverpa armigera （Hübner）antennae, a new COE gene，named HaCXE6, was cloned from Helicoverpa armigera male antennae ( GenBank No. JX306730 ) by RT-PCR and RACE stratery. The open reading frame is 1 623 bp in length, and encodes 540 amino acid residues with the predicted protein molecular mass of 61. 02 KDa and isoelectric point of 8.06. Multiple sequence alignment analysis revealed that the deduced amino acid sequence has highest identity ( 68% ) with Spodoptera littoralis antennal esterase CXE6. Phylogenetic analysis indicated that HaCXE6 has the closest evolutional relationship with Helicoverpa armigera odorant degrading enzyme CCE006a among different cotton bollworm COEs. The multiple sequence alignment of HaCXE6 and other insect COEs showed that HaCXE6 has the structure characteristic of esterases, including the catalytic triad ( Ser199, Glu323, His434 ) and the conserved mitif Gly-x-Ser-x-Gly in the α/β-esterases family. qPCR was used to analyze the mRNA of HaCXE6 in different tissues and developmental stages in H. armigera. HaCXE6 is a ubiquitous gene and could be detected in all checked tissues and mainly expresses in female abdomen and male legs. And HaCXE6 expresses at all developmental stages and peak in pupa stage.