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期 刊 ：植物保护学报 2005年

关键词：麦长管蚜；G蛋白β亚基；基因克隆；半定量RT-PCR；组织分布；

Keywords:Sitobion avenae, gene of G-protein β subunit, cloning, RQRT-PCR, tissue distribution,

摘 要 ：根据所有已知G蛋白β亚基的保守区设计简并性寡核苷酸引物,通过3‘-和5‘-RACE方法结合RT-PCR技术,从麦长管蚜中分离全长cDNA序列,并用半定量RT-PCR的方法研究基因在不同组织的转录水平。克隆的β亚基序列全长1336 bp,编码区1023 bp, 编码340个aa,推测的分子量为37.27 kDa,等电点为5.56。GenBank BLAST结果表明, β亚基与冈比亚蚊Anopheles gambiae的氨基酸序列同源性最高,为93%,与果蝇Drosophila melanogaster β₁的同源性为90%,与线虫Caenorhabditis elegans的同源性为85%,与哺乳动物β₂的同源性为80%。该亚基在麦蚜头、胸和腹部都能表达,但在头部的表达量最高,推测该种类型的β亚基可能参与多种信号传导途径的调控。该基因首次从麦蚜中克隆到,命名为SavGβ,在GenBank中的登录号为AY205294。

Abstract:In this paper, we aimed to identify and characterize the G-protein β subunit from English grain aphid, Sitobion avenae by RT-PCR and (3‘/5‘)-RACE technique, and tissue specific expression was determined by relative quantitative RT-PCR (RQRT-PCR). The full-length cDNA of β subunit is 1336 bp, which includes an open reading frame of 1023 base pairs that predicts a 340-amino acid polypeptide with calculated molecular weight of 37.27 kDa and isolectric point of 5.749. The deduced amino acid sequence of β subunit is 93%, 90% and 80% identical to Anopheles gambiae, Drosophila melanogaster and mammals (β₂), respectively. RQRT-PCR results showed that the β subunit mRNA is expressed in multiple tissues of adult aphids, but higher levels in heads than in breast and abdomen. It is predicted that the β subunit could participate in the regulation of widely distributed signal transduction pathways in the aphid. G-protein β subunit gene, named SavGβ, is isolated from Sitobion avenae and GenBank accession number is AY205294.

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