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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。
Odor receptors play an important role in insect recognition of the external odor, and their research can help us understand the molecular mechanism of insect odor recognition. In this paper, 11 odorant receptor sequences were cloned by RT-PCR from Helicoverpa armigera (Hübner) (GenBank accession number: EU599565 ~ EU599568, EU818702 ~ EU818706, FJ393455). Sequence analysis showed that HarmOR2 was an atypical odor receptor and others were typical odor receptors. Phylogenetic tree showed that HarmOR10 had a close evolutionary relationship with Drosophila melanogaster DOR46a, whereas HarmOR4 clustered with Drosophila taste receptors. The rest of the odorant receptors of Helicoverpa armigera and the Heliothis virescens odorant receptors of Heliothis virescens were clustered further and evolve more distantly from the odorant receptors of D. melanogaster, alone or in combination. The expression profiles of these odorant receptors were studied by semi-quantitative RT-PCR. The results showed that HarmOR2 was expressed in the antenna and beak of H. armigera, and its expression was comparable between male and female. The other receptors were specifically expressed in adult antennae. HarmOR3, HarmOR13 and HarmOR14 were only expressed in the male antennae. The expression levels of HarmOR12 and HarmOR20 in the female antennae were higher than those in the male antennae. The expression levels of the other scent receptors in the antennae were similar .