Stable populations in unstable habitats: temporal genetic structure of the introduced ascidian Styela plicata in North Carolina
Stable populations in unstable habitats: temporal genetic structure of the introduced ascidian Styela plicata in North Carolina
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DOI：
10.1007/s00227-016-2829-7
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发表时间：
2016-03-01
期刊：
影响因子：
2.4
通讯作者：
Lopez-Legentil, Susanna
中科院分区：
文献类型：
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作者：
Carmen Pineda, M.;Turon, Xavier;Lopez-Legentil, Susanna
时间遗传变异的分析是揭示和预测引进物种动态的一个重要但在很大程度上被忽视的工具。我们在这里描述的时间遗传结构和多样性随着时间的推移的海鞘海鞘褶皱海鞘（Lesueur，1823）在威尔明顿（北卡罗来纳州，美国，34 08/24“N，77 5144“W）的人口。这一种群遭受重要的盐度和温度变化，每年6月，我们观察到大量死亡，留下一个月内被同化的游离基质。我们采集了12-14个S.对2007 - 2009年每2个月采集的196只中国褶纹伊蚊（N = 196）进行了线粒体标记（细胞色素氧化酶亚基I，COI）和7个核微卫星分析。群体遗传分析表明，这两种类型的标记的结果相似，并揭示了大部分的遗传变异被发现的时间段内。然而，与微卫星位点进行的分析也显示出弱，但显着的时间段之间的差异。具体而言，在采样后死亡事件（2007年8月至11月和2008年）的遗传多样性增加，近交系数显着下降，有一个净增益的等位基因的微卫星位点。总的来说，我们的研究结果表明，来自邻近种群的新兵迅速占据了新的可用空间，带来了新的等位基因。然而，其他变化的遗传多样性和等位基因的损失和增益事件观察到在2008年12月-1月和2月-3月，分别，显然是独立的死亡事件。总体而言，我们的研究结果表明，调查的人口是稳定的，随着时间的推移，并依赖于定期到达的幼虫从其他人口，保持高的遗传多样性和复杂的相互作用的等位基因的增益和损失。
The analysis of temporal genetic variability is an essential yet largely neglected tool to unveil and predict the dynamics of introduced species. We here describe the temporal genetic structure and diversity over time of an introduced population of the ascidian Styela plicata (Lesueur, 1823) in Wilmington (North Carolina, USA, 34 08/24"N, 77 5144"W). This population suffers important salinity and temperature changes, and in June every year we observed massive die -offs, leaving free substratum that was recolonized within a month. We sampled 12-14 individuals of S. plicata every 2 months from 2007 to 2009 (N = 196) and analyzed a mitochondrial marker (the gene cytochrome oxidase subunit I, COI) and seven nuclear microsatellites. Population genetic analyses showed similar results for both types of markers and revealed that most of the genetic variation was found within time periods. However, analyses conducted with microsatellite loci also showed weak but significant differences among time periods. Specifically, in the samplings after die-off episodes (August November 2007 and 2008) the genetic diversity increased, the inbreeding coefficient showed prominent drops, and there was a net gain of alleles in the microsatellite loci. Taken together, our results suggest that recruits arriving from neighboring populations quickly occupied the newly available space, bringing new alleles with them. However, other shifts in genetic diversity and allele loss and gain episodes were observed in December January and February March 2008, respectively, and were apparently independent of die-off events. Overall, our results indicate that the investigated population is stable over time and relies on a periodic arrival of larvae from other populations, maintaining high genetic diversity and a complex interplay of allele gains and losses.