Abstract:

Objective The housefly Musca domestica (Diptera: Muscidae), possess significant health concerns for humans and animals. Research on genetics and molecular biology of this pest is helpful for developing an effective control strategy. Methods Frequencies of pyrethroid resistance alleles were compared for five field-derived housefly populations collected across China over a three-years interval. Results Under the laboratory conditions without insecticide selection over almost 3 years, the frequencies of resistant allele (CYP6D1v1) increased in Guangdong, Shanghai, and Beijing populations, but declined in Shandong and Jilin populations that had low initial frequencies of CYP6D1v1 allele. Guangdong, Shandong and Jilin populations experienced a significant decline in the frequency of voltage-sensitive sodium channel resistance allele (kdr-his). The most notable change was observed in Shandong population, in which kdr-his disappeared from the initial frequency of 0.33. From these observations, we concluded that CYP6D1v1 may have fitness advantages and kdr-his allele has haplotype-variable fitness. Conclusion These findings reconfirm our previous suggestion that resistance management strategy should be customized for a given location.

Key words: Musca domestica, Insecticide resistance, Pyrethroid CYP6D1, Voltage-sensitive sodium channel, Allele frequency

摘要：

目的 家蝇是一种广泛分布的重要公共卫生害虫, 开展其遗传学、分子生物学的研究为认识和利用家蝇, 有效地控制蝇传疾病提供科学依据。方法 检测我国5个家蝇种群中拟除虫菊酯类杀虫剂抗性等位基因的频率, 通过分析在无杀虫剂选择条件下抗性等位基因频率的变化, 推测抗性等位基因适合度效应。结果 研究数据显示, 与拟除虫菊酯类代谢抗性相关联的细胞色素P450(CYP6D1v1)抗性等位基因在广东、上海和北京家蝇种群中频率上升, 表明CYP6D1v1抗性等位基因不存在适合度代价;而CYP6D1v1等位基因在起始频率很低的山东和吉林种群中消失, 可能是遗传漂变的结果。家蝇钠离子通道(Vssc)抗性等位基因(kdr-his)频率在广东、山东和吉林种群中下降, 而在上海和北京种群中则有所上升, 其中变化最大的是山东种群, kdr-his基因频率由起始较高的0.33降至0, 表明kdr-his等位基因的适合度因种群的不同而不同。进一步的序列分析表明, kdr-his等位基因可以区分为不同的单倍型, 上述kdr-his基因频率的变化因种群而异, 可能是因为不同家蝇种群其钠离子通道基因单倍型有所不同。结论 不同的抗性基因或相同基因的不同单倍型具有不同的适合度, 提示家蝇抗药性检测和抗性治理要因地制宜。

关键词: 家蝇, 抗药性, 拟除虫菊酯, 细胞色素P450, 钠离子通道, 等位基因频率