Oceanic dispersal barriers, adaptation and larval retention: an interdisciplinary assessment of potential factors maintaining a phylogeographic break between sister lineages of an African prawn.
Oceanic dispersal barriers, adaptation and larval retention: an interdisciplinary assessment of potential factors maintaining a phylogeographic break between sister lineages of an African prawn.
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DOI：
10.1186/1471-2148-8-341
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发表时间：
2008-12-24
影响因子：
3.4
通讯作者：
Barker NP
中科院分区：
文献类型：
--
作者：
Teske PR;Papadopoulos I;Newman BK;Dworschak PC;McQuaid CD;Barker NP
分离具有潜在高传播能力的海洋生物区域谱系的基因突变通常被归因于传播障碍，如洋流或上升流，或促进自我招募的行为策略。我们通过研究东南部非洲生物地理分离的河口泥虾Upogebia africana的两个形态上可区分的遗传谱系，研究了这种模式是否也可以通过对不同环境条件的适应来潜在地解释。研究区处于温带生物群和亚热带生物群之间的过渡地带，温暖的、向南流动的阿古拉斯流偏离海岸，其近岸边缘以间歇性上升流为特征。为了确定这种系统地理突变是如何维持的，我们估计了该地区种群之间的基因流，测试了距离隔离作为幼虫保留的指示，并在不同温度范围内饲养了温带和亚热带谱系的幼虫。在采样的四个种群中，最北端的两个种群完全包括亚热带世系，中部种群兼有两个世系，最南端的河口只有温带世系的单倍型。没有发现距离隔离的证据，相邻种群之间的基因流动是双向的，规模相似。两个品系幼虫发育的最适温度在23℃左右，但在较低的温度下有明显的差异。温带海流的幼虫在12℃以下即可发育完成，而亚热带海流的幼虫在17℃以下发育不完全。结果表明，亚热带海流亚热带海流向南扩散及其在温带省的建立，可能主要受水温低的限制。没有证据表明，温带血统的幼虫在亚热带省份的生存状况不如在其原生栖息地，它们被排除在这一区域之外，可能是由于上升流、幼虫持续时间短、在海岸附近的扩散潜力有限，以及被困在阿古拉海流中的幼虫离开海岸。这项研究展示了如何将不同研究领域(遗传学、生理学、海洋学和形态学)的方法结合起来研究系统地理模式。
Genetic breaks separating regional lineages of marine organisms with potentially high broadcasting abilities are generally attributed either to dispersal barriers such as currents or upwelling, or to behavioural strategies promoting self-recruitment. We investigated whether such patterns could potentially also be explained by adaptations to different environmental conditions by studying two morphologically distinguishable genetic lineages of the estuarine mudprawn Upogebia africana across a biogeographic disjunction in south-eastern Africa. The study area encompasses a transition between temperate and subtropical biotas, where the warm, southward-flowing Agulhas Current is deflected away from the coast, and its inshore edge is characterised by intermittent upwelling. To determine how this phylogeographic break is maintained, we estimated gene flow among populations in the region, tested for isolation by distance as an indication of larval retention, and reared larvae of the temperate and subtropical lineages at a range of different temperatures. Of four populations sampled, the two northernmost exclusively included the subtropical lineage, a central population had a mixture of both lineages, and the southernmost estuary had only haplotypes of the temperate lineage. No evidence was found for isolation by distance, and gene flow was bidirectional and of similar magnitude among adjacent populations. In both lineages, the optimum temperature for larval development was at about 23°C, but a clear difference was found at lower temperatures. While larvae of the temperate lineage could complete development at temperatures as low as 12°C, those of the subtropical lineage did not complete development below 17°C. The results indicate that both southward dispersal of the subtropical lineage inshore of the Agulhas Current, and its establishment in the temperate province, may be limited primarily by low water temperatures. There is no evidence that the larvae of the temperate lineage would survive less well in the subtropical province than in their native habitat, and their exclusion from this region may be due to a combination of upwelling, short larval duration with limited dispersal potential near the coast, plus transport away from the coast of larvae that become entrained in the Agulhas Current. This study shows how methods from different fields of research (genetics, physiology, oceanography and morphology) can be combined to study phylogeographic patterns.
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影响因子：
2.5
作者：
Evans, BS;Sweijd, NA;Elliott, NG
通讯作者：
Elliott, NG
影响因子：
2.5
作者：
Gopal, K.;Tolley, K. A.;Matthee, C. A.
通讯作者：
Matthee, C. A.
影响因子：
4.1
作者：
Latta RG
通讯作者：
Latta RG
影响因子：
2.6
作者：
Excoffier, Laurent;Laval, Guillaume;Schneider, Stefan
通讯作者：
Schneider, Stefan
影响因子：
1.8
作者：
Matthee, Conrad A.;Cockcroft, Andrew C.;von der Heyden, Sophie
通讯作者：
von der Heyden, Sophie