Digestive Disease Hospital of Shandong First Medical University, Shandong Institute of Parasitic Diseases Shandong First Medical University & Shandong Academy of Medical Sciences, Jining, China.
Shandong Center for Disease Control and Prevention, Jinan, China.
PLoS Negl Trop Dis. 2024 Sep 12;18(9):e0011944. doi: 10.1371/journal.pntd.0011944. eCollection 2024 Sep.
Vector-borne diseases leave a large footprint on global health. Notable culprits include West Nile virus (WNV), St. Louis encephalitis virus (SLEV), and Japanese encephalitis virus (JEV), all transmitted by Culex mosquitoes. Chemical insecticides have been widely used to reduce the spread of mosquito-borne diseases. Still, mosquitoes are becoming more and more resistant to most chemical insecticides which cause particular harm to the ecology. Wolbachia belongs to the family Ehrlichiaceae in the order Rickettsiales and is a matrilineally inherited endosymbiont present in 60% of insects in nature. Wolbachia is capable of inducing a wide range of reproductive abnormalities in its hosts, such as cytoplasmic incompatibility, and can alter mosquito resistance to pathogen infection. Wolbachia has been proposed as a biological alternative to chemical vector control, and specific research progress and effectiveness have been achieved. Despite the importance of Wolbachia, this strategy has not been tested in Culex pipiens pallens, the most prevalent mosquito species in Shandong Province, China. Little is known about how the mass release of Wolbachia-infected mosquitoes may impact the genetic structure of Culex pipiens pallens, and how the symbiotic bacterium Wolbachia interacts with mitochondria during host mosquito transmission. Based on the population genetic structure of Culex pipiens pallens in Shandong Province, this study investigated the infection rate and infection type of Wolbachia in Shandong Province and jointly analysed the evolutionary relationship between the host mosquito and the symbiotic bacterium Wolbachia. Our study showed that Wolbachia naturally infected by Culex pipiens pallens in Shandong Province was less homologous to Wolbachia infected by Aedes albopictus released from mosquito factory in Guangzhou. Our results also show that Culex pipiens pallens is undergoing demographic expansion in Shandong Province. The overall Wolbachia infection rate of Culex pipiens pallens was 92.8%, and a total of 15 WSP haplotypes were detected. We found that the genetic diversity of Wolbachia was low in Culex pipiens pallens from Shandong Province, and the mosquitoes were infected only with type B Wolbachia. Visualizing the relationship between Culex pipiens pallens and Wolbachia using a tanglegram revealed patterns of widespread associations. A specific coevolutionary relationship exists between the host mosquito and Wolbachia. Knowledge of this mosquito-Wolbachia relationship will provide essential scientific information required for Wolbachia-based vector control approaches in Shandong Province and will lead to a better understanding of the diversity and evolution of Wolbachia for its utility as a biocontrol agent.
虫媒传染病在全球健康中留下了深刻的印记。西尼罗河病毒（WNV）、圣路易斯脑炎病毒（SLEV）和日本脑炎病毒（JEV）等都是由库蚊传播的，都是臭名昭著的罪魁祸首。化学杀虫剂已被广泛用于减少蚊媒疾病的传播。然而，蚊子对大多数化学杀虫剂的抵抗力越来越强，这对生态造成了特别的危害。沃尔巴克氏体属于立克次体目 rickettsiales 中的埃利希氏体科，是一种母系遗传的内共生体，自然界中 60%的昆虫都存在这种共生体。沃尔巴克氏体能够在宿主中诱导广泛的生殖异常，如细胞质不相容性，并能改变蚊子对病原体感染的抵抗力。沃尔巴克氏体已被提议作为化学媒介控制的生物替代物，并取得了具体的研究进展和效果。尽管沃尔巴克氏体很重要，但这种策略尚未在山东省最常见的蚊子白纹伊蚊中进行测试。关于大量释放感染沃尔巴克氏体的蚊子可能如何影响白纹伊蚊的遗传结构，以及共生菌沃尔巴克氏体在宿主蚊子传播过程中如何与线粒体相互作用，人们知之甚少。本研究基于山东省白纹伊蚊的种群遗传结构，调查了山东省白纹伊蚊中沃尔巴克氏体的感染率和感染类型，并共同分析了宿主蚊子与共生菌沃尔巴克氏体之间的进化关系。我们的研究表明，山东省白纹伊蚊自然感染的沃尔巴克氏体与广州蚊厂释放的白纹伊蚊感染的沃尔巴克氏体同源性较低。我们的结果还表明，山东省白纹伊蚊正在经历种群扩张。白纹伊蚊的总沃尔巴克氏体感染率为 92.8%，共检测到 15 种 WSP 单倍型。我们发现，山东省白纹伊蚊的沃尔巴克氏体遗传多样性较低，仅感染 B 型沃尔巴克氏体。使用缠结图直观地显示白纹伊蚊与沃尔巴克氏体之间的关系，揭示了广泛关联的模式。宿主蚊子和沃尔巴克氏体之间存在特定的共同进化关系。了解这种蚊子-沃尔巴克氏体的关系将为山东省基于沃尔巴克氏体的媒介控制方法提供必要的科学信息，并将有助于更好地了解沃尔巴克氏体的多样性和进化，以将其用作生物控制剂。
