麦长管蚜烟碱型乙酰胆碱受体基因的克隆和序列分析

昆虫烟碱型乙酰胆碱受体(nicotinic acetylcholine receptor, nAChR)是杀虫剂的重要作用靶标之一。本研究利用简并引物PCR和半巢式PCR技术从麦长管蚜Sitobion avenae (Fabricius)中克隆nAChR基因，成功地获得了5个α型nAChR亚基的cDNA片段。根据5个α亚基片段设计特异引物，结合快速扩增cDNA末端(RACE)技术，成功克隆了5个α型亚基的全长，并发现α5亚基有两种存在形式，它们仅在胞外区有一段175 bp的片段有差异。序列分析发现，这些基因均具有nAChR基因家族的典型特征，并与已报道的其他昆虫的烟碱型乙酰胆碱受体的相应亚基具有很高的同源性。该研究为进一步利用基因表达技术研究昆虫nAChR的天然亚基组成，以及分析麦长管蚜对新烟碱类杀虫剂的靶标抗性，奠定了基础。

Cloning and sequence analysis of nicotinic acetylcholine receptor subunits from the grain aphid, Sitobion avenae (Fabricius)

Nicotinic acetylcholine receptor (nAChR) is one of the most important insecticide targets. In this study, five α-subunit genes from the grain aphid, Sitobion avenae (Fabricius) were cloned to their full-length with RT-PCR and RACE strategy. It was also found that the α5 subunit had two forms with only difference in a 175 bp fragment. Sequence analysis showed that these genes had all the characteristics of nAChR gene family and were high homology with the reported nAChR genes from other insects. This work facilitates the further studies on natural subunit composition of nAChR and the molecular mechanisms for target resistance to new nicotinic insecticides in this pest.