烟粉虱烟碱型乙酰胆碱受体α亚基Btα4基因的克隆和序列分析

Cloning and sequence analysis of a α-subunit gene of nicotinic acetylcholine receptor from Bemisia tabaci(Gennadius)

利用RT-PCR和RACE技术,对烟粉虱烟碱型乙酰胆碱受体(nAChR)α亚基的1个基因进行了克隆和序列分析。获得的烟粉虱nAChRα亚基基因的全长cDNA序列含有2 090 bp,其开放阅读框编码564个氨基酸。根据该基因编码的氨基酸序列与其他昆虫乙酰胆碱受体α亚基氨基酸序列之间的相似性,将该基因命名为Btα4(GenBank注册号为EF590120)。Btα4编码的α亚基含有2个结构域:N端的胞外结构域和C端的跨膜结构域,N端的胞外结构域含有2个相邻的半胱氨酸(α亚基特征序列)、15个氨基酸构成的半胱氨酸环和乙酰胆碱结合区。研究结果对于揭示烟粉虱潜在的对新烟碱类杀虫剂靶标抗性的分子机制具有重要意义。

Nicotinic acetylcholine receptor （nAChR） is one of the most important target sites of insecticides in insects. An nAChR α subunit gene was cloned by using RT-PCR and RACE and sequenced from the whitefly, Bemisia tabaci. The complete eDNA sequence of this gene contained 2 090 bp and encoded a protein of 564 amino acids. This gene was designated as Bta4 （GenBank accession number EF590120 ） according to its amino acid similarity to other insect nAChR. The putative α subunit encoded by Btα4 included two domains, the C-terminal extracellular domain and the N-terminal transmembrane domain. The N-terminal extracellular domain of Btα4 subunit contains two adjacent cysteine residues （ typical character for α-subunit） , a cysteine loop and aeetyleholine binding regions. The current study has significance for investigating potential target site resistance mechanism of Bemisia tabaci to neonicotinoids.