Gene cloning and expression profiling of atypical odorant receptors Orco gene in Bactrocera dorsalis (Hendel) | 桔小实蝇非典型气味受体Orco基因的克隆与表达谱分析

Chinese. 为探讨非典型气味受体基因Orco的功能，采用RT-PCR和RACE方法克隆获得桔小实蝇Bactoceradorsalis（Hendel）Orco受体的全长cDNA序列，命名为Bdor／Orco（GenBank登录号为EU621792）。测序结果表明Bdor／Orco开放阅读框全长1422bp，编码473个氨基酸残基。对其组成成分、疏水／亲水区域、信号肽、蛋白质二级结构，以及分子进化关系等进行了预测与推断，分析结果表明Bdor／Orco与其他昆虫的Orco具有较高的氨基酸序列一致性，特别是C末端。对该基因在桔小实蝇成虫不同组织和发育时期表达量的荧光定量PCR分析，结果表明Bdor／Orco主要是在桔小实蝇成虫触角中表达，头部（去除触角）、雌虫前足和翅中也有较高的表达；桔小实蝇在各个发育时期的表达水平不同，在刚羽化雌成虫中的表达量最高。

English. In order to explore the functions of Orco, the gene encoding Orco from Bactrocera dorsa- lis （Hendel） was cloned and named as Bdor/Orco （GenBank accession No. EU621792） by RT-PCR and RACE. The sequencing results showed that the open reading frame of Bdor/Orco was 1 422 bp in length,encoding 473 amino acid residues. The Bdor/Orco was analyzed and predicted by the tools of bioinformatics in the following aspects： the composition, hydrophobicity or hydrophilicity, the signal peptide, protein secondary structure, the composition of homologous protein and the phylogenetic rela- tionship. The results showed Bdor/Orco had the characteristics of Orco, with special conserved C domains. Tissue expression pattern revealed that Bdor/Orco transcript was observed clearly in the antenna of B. dorsalis, and highly expressed in the head （with antennae removed）, female foreleg and wing. The temporal expression pattern further indicated that Bdor/Orco was also expressed in different devel- opmental stages at different expression levels with the highest level in newly emerged female adult.