Resistance-associated point mutations of organophosphate insensitive acetylcholinesterase, in the olive fruit fly Bactrocera oleae
Resistance-associated point mutations of organophosphate insensitive acetylcholinesterase, in the olive fruit fly Bactrocera oleae
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DOI：
10.1046/j.1365-2583.2002.00343.x
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发表时间：
2002-08-01
影响因子：
2.6
通讯作者：
Hemingway, J
中科院分区：
文献类型：
--
作者：
Vontas, JG;Hejazi, MJ;Hemingway, J
采用简并PCR和RACE相结合的方法，从有机磷敏感的橘小实蝇（Bactrocera oleae）中获得了一个2.2kb的全长cDNA，该cDNA含有编码673个氨基酸残基的乙酰胆碱酯酶（AChE）前体的ORF。从敏感和抗性菌株的个体昆虫的cDNA序列的比较，再加上与氧乐果的酶抑制试验，表明一种新的甘氨酸-丝氨酸取代（G488 S），在一个氨基酸残基，这是高度保守的物种（13396的电鳐乙酰胆碱酯酶），作为一个可能的原因乙酰胆碱酯酶不敏感性。这种突变也与AChE催化效率降低35-40%有关。I199 V置换在果蝇中赋予低水平的抗性，也存在于B中。oleae（I214 V）和与G488 S组合产生高达16倍的杀虫剂敏感性降低。这是第一种农业害虫，其中抗性与AChE的改变有关，AChE的改变是由位于酶活性位点峡谷内的点突变引起的。
A 2.2-kb full length cDNA containing an ORF encoding a putative acetylcholinesterase (AChE) precursor of 673 amino acid residues was obtained by a combined degenerate PCR and RACE strategy from an organophosphate-susceptible Bactrocera oleae strain. A comparison of cDNA sequences of individual insects from susceptible and resistant strains, coupled with an enzyme inhibition assay with omethoate, indicated a novel glycine-serine substitution (G488S), at an amino acid residue which is highly conserved across species (13396 of Torpedo californica AChE), as a likely cause of AChE insensitivity. This mutation was also associated with a 35-40% reduction in AChE catalytic efficiency. The I199V substitution, which confers low levels of resistance in Drosophila, was also present in B. oleae (I214V) and in combination with G488S produced up to a 16-fold decrease in insecticide sensitivity. This is the first agricultural pest where resistance has been associated with an alteration in AChE, which arises from point mutations located within the active site gorge of the enzyme.