蜂巢小甲虫OBP4的克隆及表达谱分析

本研究克隆获得了一个新的蜂巢小甲虫Aethina tumida的气味结合蛋白(odorant-binding proteins, OBPs)基因，并对其序列特征、表达情况、系统发育进行研究。该蜂巢小甲虫气味结合蛋白基因命名为AtumOBP4(GenBank登录号：ON813082),开放阅读框全长465 bp,编码154个氨基酸，预测其分子量大小为17.4 kDa,理论等电点为5.07。N末端有23个氨基酸组成的信号肽，具有6个保守的半胱氨酸位点，属于Classical OBP亚家族，系统进化树分析表明其与黄粉虫Tenebrio molitor OBP8亲缘关系最近。qRT-PCR结果显示AtumOBP4在雄性成虫中表达量显著高于雌性成虫且在头部(包含触角)特异性高表达，羽化后第7天达到最高值。推测AtumOBP4在蜂巢小甲虫嗅觉识别一般气味或性信息素过程中发挥重要作用。此外，成功构建了pET32a(+)/AtumOBP4重组表达载体并通过原核表达获得了重组蛋白，为后期深入研究AtumOBP4蛋白功能奠定了基础，也为进一步研究OBP家族基因在蜂巢小甲虫寻找寄主蜂箱的嗅觉机制中提供了丰富...

Cloning and expression profiling of OBP4 gene in Aethina tumida (Coleoptera: Nitidulidae)

In this study, a new odorant-binding proteins (OBPs) gene of Aethina tumida was cloned and obtained, and the sequence characteristics, expression pattern and phylogenetic evolution were studied. The odorant binding protein from A. tumida, was named AtumOBP4 (GenBank accession number: ON813082). The sequence analysis showed that the open reading frame (ORF) of AtumOBP4 was 465 bp encoding 154 amino acids, the predicted molecular weight was 17.40 kDa, and the isoelectric point (pI) was 5.07. The predicted N-terminal region containing 23 amino residues displayed the characteristic features of a signal peptide. It contained six conserved cysteine sites and belonged to the Classical OBP subfamily. Phylogenetic analysis showed that the AtumOBP4 and Tenebrio molitor OBP8 were clustered into one branch and had a high homology. qRT-PCR results showed that the expression of AtumOBP4 was significantly higher in male than in female adults and was specifical highly expressed in the head (including antennae), reaching the highest value on the 7th day after eclosion. It is hypothesized that AtumOBP4 plays an important role in olfactory recognition of general odors or sex pheromones in small hive beetles. In addition, the pET32a(+)/AtumOBP4 recombinant expression vector was successfully constructed and the recombinant protein was obtained by prokaryotic expression, which laid the foundation for later in-depth study on the function of AtumOBP4 protein and also provided a rich theoretical basis for further study on the olfactory mechanism of OBP family genes in the search of host hives by small hive beetles.