摘要： 为了探讨Meis家族中Homothorax基因在昆虫中的表达特性，以松墨天牛为研究对象，从cDNA文库中筛选到松墨天牛Homothorax基因，命名为MaHth（GenBank：KX364396）。该序列长为1 347 bp，编码448个氨基酸。由此预测的蛋白质二级结构主要由α螺旋与无规则卷曲组成，其次是β转角与延伸链；SWISS-MODEL同源建模预测其三级结构的基元为α螺旋-β转角-α螺旋。MaHth基因编码蛋白，定位于细胞核，并存在2个独立的核定位信号：KRDK、KKNQKKR。通过DNAMAN软件比对发现MaHth与赤拟谷盗同源性最高，为97%，且存在Hox保守结构域序列；用MEGA 4.0构建系统发育树，显示松墨天牛与赤拟谷盗处在同一分支。通过RT-qPCR分析表明：卵、蛹中的表达量比幼虫、成虫中的高，在成虫中最低；幼虫头部中MaHth表达量最高，马氏管中表达量较低；成虫头部、马氏管中MaHth表达量最高，足、翅、触角中表达量较低。

关键词: 松墨天牛, Homothorax, cDNA文库, RT-qPCR

Abstract: To explore the expression characteristics of Homothorax gene from Meis family in insects, Homothorax gene was filtrated from cDNA library of Monochamus alternatus, as the research object, named MaHth (GenBank:KX364396).The sequence of MaHth was 1 347 bp in length, encoding 448 amino acids. The predicted secondary structure of MaHth was mainly composed of alpha helix with random curl, followed by the beta turn with the extension chain. Subcellular localization of the gene was in nucleus. There were two independent nuclear localization signals:KRDK and KKNQKKR.Through DNAMAN software,amino acids sequence multiple alignment analysis of MaHth showed the highest homology with Tribolium castaneum (97%). Phylogenetic tree built by MEGA 4.0 indicated M. alternatus with T.castaneum were in the same branch. By RT-qPCR technology,gene analysis showed that MaHth expression level in eggs and pupae were higher than that in larvae and adults, and the lowest in adults.In larvae, MaHth had the highest expression level in heads, nevertheless,the lowest in malpighian tubes. In adults, MaHth reached the highest expression level in heads and malpighian tubes. Expression was at low level in feet, wings and antennae.

Key words: Monochamus alternatus, Homothorax, cDNA library, RT-qPCR

中图分类号: 

• Q966

• Q78