Phylogeography of Aedes Aegypti in Argentina: Long-Distance Colonization and Rapid Restoration of Fragmented Relicts After a Continental Control Campaign
Phylogeography of Aedes Aegypti in Argentina: Long-Distance Colonization and Rapid Restoration of Fragmented Relicts After a Continental Control Campaign
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DOI：
10.1089/vbz.2011.0696
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发表时间：
2012-03-01
影响因子：
2.1
通讯作者：
Noemi Gardenal, Cristina
中科院分区：
文献类型：
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作者：
Albrieu Llinas, Guillermo;Noemi Gardenal, Cristina
埃及伊蚊是登革热和黄热病病毒的主要传播媒介，在阿根廷北部和中部所有省份都有存在。2009年，登革热暴发在全国广泛传播，在13个省造成27,752人感染。在阿根廷，人们对这种媒介的人口学历史知之甚少，1950年至1960年在美洲开展的一次重大防治运动中，这种媒介的丰度和分布急剧下降。旨在揭示决定Ae基因变异性目前分布的过去和现在的事件。在埃及伊蚊种群中，我们分析了通过对ND5基因450个碱基片段测序获得的线粒体单倍型的分布和丰度。我们在22个种群的197个个体的序列中检测到14个单倍型，覆盖了阿根廷物种的大部分分布；还包括一个来自玻利维亚的种群和一个来自巴拉圭的种群。在阿根廷西北部，观察到遗传多态的地理分布具有高度的异质性，具有按距离隔离的模式。单倍型嵌套在三个单倍群中，代表了遥远地理区域的不同殖民事件和进化史。西北部和东北部的种群对应于独立引进的种群，其过去的碎片化和从高度多态的遗迹中快速恢复被推断出来。相比之下，在东部发现了一种独特的基因变异，这可能是由于最近在主要控制运动之后发生的重新殖民事件的结果；在这一地区，由于大陆控制运动的结果，蚊子实际上已经被根除。
Aedes (Stegomyia) aegypti, the main vector of Dengue and Yellow Fever viruses, is present in all the northern and central provinces of Argentina. During 2009, a Dengue outbreak spread broadly throughout the country, causing 27,752 infections in 13 provinces. In Argentina, little is known about the demographic history of this vector, which suffered a drastic decrease in abundance and distribution during a major control campaign performed in the Americas between 1950 and 1960. With the aim of uncovering the past and present events that determined the present distribution of the genetic variability in Ae. aegypti populations, we analyzed the distribution and abundance of mitochondrial haplotypes obtained by sequencing a 450-bp fragment of the ND5 gene. We detected 14 haplotypes among the sequences of 197 individuals from 22 populations that cover most of the distribution of the species in Argentina; one population from Bolivia and one from Paraguay were also included. A high heterogeneity in the geographical distribution of the genetic polymorphism was observed, with a pattern of isolation by distance in the north-west of Argentina. Haplotypes nested in three haplogroups, representing different colonization events and evolutionary histories in distant geographical areas. North-western and northeastern populations correspond to independent introduced stocks for which a past fragmentation and rapid restoration from highly polymorphic relicts were inferred. By contrast, a unique genetic variant was detected in the east, probably as the result of a recent re-colonization event after the major control campaign; in this area, the mosquito would have been practically eradicated as a consequence of the continental control campaign.