Department of Public Health Sciences, Miller School of Medicine, University of Miami, Miami, FL, United States.
Department of Epidemiology, School of Public Health, University of São Paulo, Av. Dr. Arnaldo 715, São Paulo, SP CEP-01246-904, Brazil.
Infect Genet Evol. 2018 Nov;65:333-339. doi: 10.1016/j.meegid.2018.08.017. Epub 2018 Aug 22.
Culex nigripalpus Theobald (Diptera: Culicidae) is a native species of Brazil that is well adapted to urban environments and found extensively in the city of São Paulo, Brazil. As a native species, it has been present in this region since long before the foundation of the city, but over time Cx. nigripalpus populations have been affected by man-made changes to the environment. We hypothesize that the populations analyzed in this study constituted a large Cx. nigripalpus population that separated into smaller populations as a result of increased levels of urbanization in the city, and that such high levels of urbanization would result in a genetic homogenization effect. We therefore investigated the microgeographic genetic structure and microevolutionary processes in Cx. nigripalpus populations from seven different locations in the city of São Paulo using a set of six microsatellite primers originally developed for Culex quinquefasciatus and Culex pipiens. Our results indicate that Cx. nigripalpus did not benefit from urbanization and is currently under selective pressures caused by anthropogenic changes and that populations from areas with higher levels of urbanization exhibited similar genetic patterns and low levels of polymorphism, contrasting with the more sylvatic SHA population. These findings are likely to contribute to a better understanding of how anthropogenic selective pressures are driving population genetics and, to some extent, the dynamics of Cx. nigripalpus populations. They should also help elucidate the effects that urbanization processes have on the ecology and behavior of these mosquito populations.
巴西刺扰伊蚊（Culex nigripalpus Theobald）（双翅目：蚊科）是一种原产于巴西的物种，它非常适应城市环境，在巴西圣保罗市广泛存在。作为一个本地物种，它自城市建立之前就已经存在于该地区，但随着时间的推移，刺扰伊蚊的种群受到了人为环境变化的影响。我们假设本研究中分析的种群构成了一个庞大的刺扰伊蚊种群，由于城市的城市化水平不断提高，这些种群已经分离成更小的种群，而这种高度的城市化会导致遗传同质化效应。因此，我们使用最初为致倦库蚊（Culex quinquefasciatus）和淡色库蚊（Culex pipiens）开发的一套 6 个微卫星引物，研究了来自巴西圣保罗市七个不同地点的刺扰伊蚊种群的微地理遗传结构和微进化过程。我们的研究结果表明，刺扰伊蚊并没有受益于城市化，目前正受到人为变化引起的选择压力的影响，而且城市化程度较高地区的种群表现出相似的遗传模式和低水平的多态性，与更具森林生境特征的 SHA 种群形成对比。这些发现可能有助于更好地理解人为选择压力如何驱动种群遗传学，在一定程度上还能阐明城市化进程对这些蚊子种群的生态学和行为的影响。
