Evidence for temporal population replacement and the signature of ecological adaptation in a major Neotropical malaria vector in Amazonian Peru.
Evidence for temporal population replacement and the signature of ecological adaptation in a major Neotropical malaria vector in Amazonian Peru.
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DOI：
10.1186/s12936-015-0863-4
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发表时间：
2015-09-29
期刊：
影响因子：
3
通讯作者：
Conn JE
中科院分区：
文献类型：
--
作者：
Lainhart W;Bickersmith SA;Nadler KJ;Moreno M;Saavedra MP;Chu VM;Ribolla PE;Vinetz JM;Conn JE
1990年代初，主要的新热带疟疾媒介达林格按蚊被重新引入秘鲁洛雷托的伊基托斯地区，在那里它取代了其他按蚊，并导致了一场重大的疟疾流行。自那以后，洛雷托的病例数量一直在波动，但自2012年以来，报告的病例数量每年都在增加。按蚊的种群遗传结构。对长效杀虫网(LLIN)引入前后的达令木样本进行了调查，以检验种群时间变化假说(2006年与2012年)。An的当前样本。Darlingi被用来检验与森林覆盖相关的人类改良(公路)与野生(河流)生境的生态适应假说。总计693个An。利用13个微卫星基因座对秘鲁洛雷托地区9个地方的大林木进行了基因分型。对栖息地分化假说进行验证。达林吉叮咬时间模式，HBR和EIR，四个集合。对来自五个地区(两条河流和三条高速公路)的达令吉进行了分析。对伊基托斯地区7个聚居地(2006年)和9个聚居地(2012-2014年)的微卫星基因座分析发现，有两个不同的种群几乎没有重叠，尽管尚不清楚这种种群替换事件是否与LLIN分布或气候有关。在2012-2014年的种群中，A和B两个混合亚种群按栖息地进行了区分，其中B在公路上的比例明显偏高，在河流中的比例几乎相等。这两个亚群都有扩张的迹象，它们之间存在适度的遗传分化。生境和森林覆盖水平对HBR有显著影响，因此，EIR测量的疟疾传播风险，在河流周边聚居地比周边公路聚居地高三倍。Hbr与有效寄主生物量直接相关，而不是与森林覆盖率相关。2006年至2012-2014年期间发生了人口更替事件，与LLIN分布和中度厄尔尼诺事件同时发生，并在疟疾发病率增加之前发生。根据当前数据，无法确定此次更换的可能驱动因素。现在的安。达令吉种群由两个高度混合的亚种群组成，这两个亚种群似乎处于分化的早期阶段，这是由当地栖息地的人为变化引发的。本文的在线版本(doi：10.1186/s12936-0150863-4)包含补充材料，授权用户可以使用。
The major Neotropical malaria vector, Anopheles darlingi, was reintroduced into the Iquitos, Loreto, Peru area during the early 1990s, where it displaced other anophelines and caused a major malaria epidemic. Since then, case numbers in Loreto have fluctuated, but annual increases have been reported since 2012. The population genetic structure of An. darlingi sampled before and after the introduction of long-lasting insecticidal nets (LLINs) was investigated to test the hypothesis of temporal population change (2006 vs. 2012). Current samples of An. darlingi were used to test the hypothesis of ecological adaptation to human modified (highway) compared with wild (riverine) habitat, linked to forest cover. In total, 693 An. darlingi from nine localities in Loreto, Peru area were genotyped using 13 microsatellite loci. To test the hypothesis of habitat differentiation in An. darlingi biting time patterns, HBR and EIR, four collections of An. darlingi from five localities (two riverine and three highway) were analysed. Analyses of microsatellite loci from seven (2006) and nine settlements (2012–2014) in the Iquitos area detected two distinctive populations with little overlap, although it is unclear whether this population replacement event is associated with LLIN distribution or climate. Within the 2012–2014 population two admixed subpopulations, A and B, were differentiated by habitat, with B significantly overrepresented in highway, and both in near-equal proportions in riverine. Both subpopulations had a signature of expansion and there was moderate genetic differentiation between them. Habitat and forest cover level had significant effects on HBR, such that Plasmodium transmission risk, as measured by EIR, in peridomestic riverine settlements was threefold higher than in peridomestic highway settlements. HBR was directly associated with available host biomass rather than forest cover. A population replacement event occurred between 2006 and 2012–2014, concurrently with LLIN distribution and a moderate El Niño event, and prior to an increase in malaria incidence. The likely drivers of this replacement cannot be determined with current data. The present-day An. darlingi population is composed of two highly admixed subpopulations, which appear to be in an early stage of differentiation, triggered by anthropogenic alterations to local habitat. The online version of this article (doi:10.1186/s12936-015-0863-4) contains supplementary material, which is available to authorized users.