棉铃虫气味受体的克隆与组织特异性表达

Cloning and tissue-specific expression of olfactory receptors in Helicoverpa armigera(Hübner)

气味受体在昆虫识别外界气味过程中起重要作用,对其的研究可以帮助我们了解昆虫对气味识别的分子机制。本文通过RT-PCR技术,在棉铃虫Helicoverpa armigera(Hübner)中克隆得到11条气味受体序列(GenBank登录号:EU599565～EU599568,EU818702～EU818706,FJ393455)。序列分析结果表明,HarmOR2为非典型气味受体,其他为典型气味受体。进化树显示,HarmOR10与黑腹果蝇Drosophila melanogaster DOR46a进化关系较近,而HarmOR4与果蝇味觉受体聚类在一起。棉铃虫其余气味受体与烟芽夜蛾Heliothis virescens气味受体单独或几个一起处于与黑腹果蝇气味受体进化关系较远的聚类中,而且彼此聚类关系较远。使用半定量RT-PCR对这些气味受体的表达谱进行研究,结果表明:HarmOR2在棉铃虫触角和喙中表达,表达量在雌雄间相当。其他受体则在成虫触角中特异表达,其中HarmOR3,HarmOR13和HarmOR14仅在雄性触角内表达;雌性触角内HarmOR12和HarmOR20的表达量要高于雄性触角;其余气味受体雌雄触角间表达量则相当。

Olfactory receptors （ORs） play a critical role in insect olfactory system. Research on ORs can help us understand the molecular mechanism of odors discrimination in insect. In this study, 11 Helicoverpa armigera OR genes （GenBank accession numbers： EU599565 - EU599568, EU818702 - EU818706, FJ393455） were cloned using RT-PCR. The results of sequence analysis showed that HarmOR2 was atypical OR and the rest 10 ORs were typical ORs. Phylogenetic tree indicated that HarmOR10 and DOr46a belonged to a single cluster, while HarmOR4 belonged to a cluster of gustatory receptors （Grs）. The other H. armigera ORs belonged to the cluster which had a long distance with Drosophila melanogaster ORs. We also found that HarmOR2 was expressed in antennae and proboscis of H. armigera, while other HarmORs were specially expressed only in the antenna of adult moth, of which HarmOR3, HarmOR13 and HarrnOR14 were expressed only in the antenna of male adult. Moreover, HarmOR12 and HarmOR20 were expressed at higher level in antenna of male than that of female, while other HarmORs were expressed at the same level both in female and in male.