Genetic and biochemical analysis of insecticide-insensitivity of acetylcholinesterase in vector mosquitoes

用三带喙库蚊（Culex tritaeniorhyncus，C.t.）的三个有机磷（OP）敏感品系和OP抗性品系富山（Toyama），以及新采集的横滨自然种群的AChE蛋白质多态性进行了研究。测试的20只野外蚊子均含有OP不敏感的AChE以及富山株。利用限制性片段长度多态性（RFLP）技术，以埃及伊蚊（Aedes aegypti）和三带喙库蚊（Culex tritaeniorhynchus）的AChE cDNA克隆为材料，构建了三带喙库蚊AChE的比较连锁图谱。OP抗性由2号染色体上的主效基因（AChE^R）控制，而AChE结构基因（Ace）位于1号染色体上。没有发现第二个Ace基因的证据，这表明AChE^R基因座代表了AChE对去乙酰化敏感性的修饰。

Protein polymorphism attributable to organophosphorus(OP) insecticide-insensitivity of acetylcholinesterase(AChE) was investigated with mosquitoes of three insecticide-suceptible strains and the OP-resistant strain, Toyama, and mosquitoes newly collected from the natural population in Yokohama of Culex tritaeniorhyncus (C.t.). All the 20 field mosquitoes tested contained OP-insensitive AChE as well as Toyama strain. No protein sequence polymorphism was detected in the deduced matured peptide of AChE in all the tested mosquitoes.A comparative linkage map for the mosquito, Culex tritaeniorhynchus, was constructed based on restriction fragment length polymorphism (RFLP) markers using cDNA clones from Aedes aegypti and AChE cDNA from C.t. OP resistance is controlled by a major gene (AChE^R) on chromosome 2, while the AChE structural gene (Ace) is located on chromosome 1. No evidence for a second Ace gene was observed, suggesting that the AChE^R locus represents a modifier of insecticide-sensitivity of AChE.