Chen Maohua, Han Zhaojun
Laboratory of Monitoring and Management of Plant Diseases and Insects, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
Genome. 2006 Mar;49(3):239-43. doi: 10.1139/g05-104.
Two genes encoding different acetylcholinesterases (AChE) were successfully cloned from 2 species of aphid, Rhopalosiphum padi (L.) and Sitobion avenae (F.). They were named Rp.AChE1 (GenBank accession No. AY707318), Rp.AChE2 (AY667435), Sa.AChE1 (AY707319), and Sa.AChE2 (AY819704), and were 2133, 2363, 2131, and 2362 bp in length and encoded 664, 676, 664, and 676 amino acids, respectively. All of them shared the characteristics of the AChE family: catalytic tiads, 3 intra-chain disulfide bridges, an acyl pocket, and the conservative aromatic residues for the active site of the gorge. Sequence analysis revealed that Rp.AChE1 and Sa.AChE1 showed higher identity to the reported orthologous genes of Drosophila AChE, and Rp.AChE2 and Sa.AChE2 to paralogous genes. However, in each of the aphids, the 2 genes from the same species shared only 29% identity between one another. It was therefore concluded that each of the aphids has 2 different AChE genes, which are either orthologous or paralogous to Drosophila AChE. The high conservation of AChE1 and AChE2 indicated that 2 acetylcholinesterases exist popularly and that both might function in aphids.
从两种蚜虫，即禾谷缢管蚜（Rhopalosiphum padi (L.)）和麦长管蚜（Sitobion avenae (F.)）中成功克隆出了两个编码不同乙酰胆碱酯酶（AChE）的基因。它们分别被命名为Rp.AChE1（GenBank登录号：AY707318）、Rp.AChE2（AY667435）、Sa.AChE1（AY707319）和Sa.AChE2（AY819704），长度分别为2133、2363、2131和2362 bp，分别编码664、676、664和676个氨基酸。它们都具有AChE家族的特征：催化三联体、3个链内二硫键、一个酰基口袋以及峡部活性位点的保守芳香族残基。序列分析表明，Rp.AChE1和Sa.AChE1与已报道的果蝇AChE直系同源基因具有更高的同源性，而Rp.AChE2和Sa.AChE2与旁系同源基因具有更高的同源性。然而，在每种蚜虫中，同一物种的两个基因彼此之间的同源性仅为29%。因此得出结论，每种蚜虫都有两个不同的AChE基因，它们与果蝇AChE要么是直系同源，要么是旁系同源。AChE1和AChE2的高度保守性表明，两种乙酰胆碱酯酶普遍存在，且两者可能在蚜虫中发挥作用。
