杭州市库蚊复组抗性相关酯酶Estβ基因类型和频率及动态分布

目的 了解杭州市尖音库蚊复组有机磷抗性相关酯酶基因类型、频率和动态分布,为蚊虫防制提供对策。方法 采用聚合酶链反应-限制性内切酶长度多态性（PCR-RFLP）方法进行抗性相关酯酶的基因分型,对2003-2005年杭州市自然种群库蚊酯酶基因的频率进行动态监测。同时结合酯酶淀粉凝胶电泳技术检测抗性酯酶基因表型监测。结果 连续3年用PCR-RFLP法对酯酶等位基因的分子分型结果表明,杭州市存在4种酯酶基因类型,主要存在世界范围内广泛分布的酯酶Estβ1（50％～54％）纯合型,其次是Estβ2（29％～34％）纯合型,Estβ1／B2（5％～10％）杂合型和一种新的EstβN（3．13％）纯合型等位基因型。用淀粉凝胶电泳分析2005年杭州市库蚊种群的抗性酯酶基因表型,主要是Estβ1型（61％）,其次是Estα2／β2型（12％）,Estαβ／β8型（7％）,敏感表型（29％）。结论 杭州市自然种群尖音库蚊复组存在多种抗性酯酶基因型,2003-2005年来Estβ1型为主,其次是Estα2／β2型,在2005年发现EstβN,是一个新的酯酶基因型,但是比例较低,仅占3．13％。该新的酯酶基因可否引起新的杀虫药剂的抗性,尚有待进一步的跟踪研究。扩增酯酶基因分子分型与抗性酯酶表型,也都表明了一致性。

Genotypes, allele frequencies and dynamic distribution on resistance-associated esterase genes of Culex pipiens complex in Hangzhou

OBJECTIVE: To investigate the genotypes , allele frequencies and dynamic distribution on resistance associated esterase genes of Culex pipiens complex in Hangzhou. METHODS: The PCR-restriction fragment length polymorphism (PCR-RFLP) assay was applied to type the resistance associated esterase genes, and dynamic surveillance on frequencies of the resistance associated esterase gene of natural population of Culex pipiens complex in Hangzhou during 2003-2005, and phenotype of the resistance associated esterase genes were detected by esterase starch gel electrophoresis technique. RESULTS: The PCR-RFLP assay of esterase allele genes for three consecutive years disclosed four esterase genotypes, namely, the world-wide highly active homozygous Est beta 1(1) (50%-54%), homozygous Est beta 2 (29%-34%), heterozygous Est beta 1(1)/beta 2 (5%-10%) and Est beta N (3.13%) of a new homozygous genotype. The research of the resistance associated esterase genes phenotype in natural population of Culex pipiens complex in Hangzhou in 2005 with esterase starch gel electrophoresis technique revealed four major types, namely, Est beta 1(1) (61%), Est alpha 2/beta 2 (12%), Est alpha 8/beta 8 (7%) and sensitive phenotype (29%). CONCLUSION: There should be various resistance associated esterase genotypes in natural population of Culex pipiens complex in Hangzhou. During the period of 2003-2005, Est beta 1(1) was the major type; Est alpha 2/beta 2 was the second. Est beta N was a new esterase genotype detected in 2005 only with a mere percentage of 3.13%. As for its resistance to the new insecticide, a follow-up study should be needed. The molecular typing of the amplified esterase gene should be consistent with the resistance associated esterase genes phenotype.