中文摘要：

目的研究自然种群尖音库蚊复组有机磷抗性相关酯酶B2基因Estβ2杂合型的分子特征。方法采集杭州市自然种群库蚊，提取单蚊DNA基因组，采用聚合酶链反应．限制性片段长度多态性（PCR—restriction fragment length polymorphism，PCR—RFLP）方法进行抗性相关酯酶的基因分型。对酯酶B2基因Estβ2型蚊虫的PCR产物，进一步选用Bfm I内切酶进行酶切，确定酯酶B2基因Estβ2纯合型及Estβ2杂合型。本次研究共提取207只单蚊DNA，156份PCR样本阳性，阳性率75．36％（156／207）。结果在156份PCR样本阳性，酯酶B2基因Estβ2型占28．20％（44／156）；对该基因型进一步分型，其中Estβ2纯合型占90．90％（30／33），Estβ2杂合型占9％（3／33）；Estβ2杂合型是以Estβ2和一种亚型杂合（Estβ2／Estβ2’）形式存在。结论建立了在自然种群尖音库蚊复组中酯酶B2基因分型方法，研究证明了杭州自然种群库蚊存在一种有机磷抗性相关酯酶B2基因Estβ2杂合型。

英文摘要：

Objective To investigate the heterozygous genotype and molecular characteristics of Organophosphorus resistance associated with heterozygous Estβ2 of esterase B2 gene from natural population of Culex pipiens complex. Methods Genomic DNA was extracted from natural populations of Culex pipiens complex in Hangzhou. The PCR-restriction fragment length polymorphism （PCR-RFLP） assay was applied to type the resistance associated esterase gene. Estβ2 of esterase B2 gene was identified by PCR-RFLP, and the genotyping for heterozygous Estβ2 was carried out after restriction enzyme digesting by Bfm I endonuclease. Results The DNA was isolated from 207 Culex pipiens respectively ,while 156 PCR samples showed positive and the positive rate was 75.36% （ 156/207 ）. The PCR-RFLP assay of esterase B2 gene revealed that the Estβ2 was accounted about 28.20% （44/156） in 156 positive samples. There were two genotypes identified, namely homozygous Estβ2 （ 90. 90%, 30/33 ） and heterozygous Estβ2 （9%, 3/33 ）, heterozygous Estβ2 was in existence of a hybrid form as which combined with Estβ2 and a subtype（ Estβ2/ Estβ2＇）. Conclusion Heterozygous Estβ2 of Organophosphorus resistance associated with esterase genotype was determined in natural population of Culex pipiens, and a genotyping method was established.