Oceanic currents drove population genetic connectivity of the brown alga Sargassum thunbergii in the north-west Pacific
Oceanic currents drove population genetic connectivity of the brown alga Sargassum thunbergii in the north-west Pacific
复制标题
洋流驱动了西北太平洋褐藻马尾藻种群的遗传连通性
DOI：
10.1111/jbi.12856
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发表时间：
2017
影响因子：
3.9
通讯作者：
Endo Hikaru
中科院分区：
文献类型：
--
作者：
Li Jing-Jing;Hu Zi-Min;Gao Xu;Sun Zhong-Min;Choi Han-Gil;Duan De-Lin;Endo Hikaru
目的海流是影响潮间带生物群落动态、种群连接性和群落地理结构的最重要的水动力学特征之一。在这里，我们测试是否种群结构和地理梯度的遗传多样性在棕色海藻鼠尾藻与洋流在西北太平洋（NWP. LocationNorth-west Pacific（25.07°N-43.36°N）.MethodsNuclear internal transcribed spacer-2和nuclear alcox 3序列分别获得835和810个个体的S. Thunbergii分别。构建了简约网络和系统发育树（最大简约和贝叶斯推理）来评估植物的地理结构。采用不同等级水平（纬度、经度、海洋省、地理盆地和动物地理区）的FST估计和AMOVA分析，探讨了种群的遗传分化，并利用migrate软件估计了相邻种群间的迁移数量。Thunbergii的特点是浅的人口结构。地理距离与群体遗传分化没有相关性。基于走廊/垫脚石模型的结合分析揭示了高水平的不对称基因流。thunbergiipumulations，与移民的数量在很大程度上对应的洋流系统在NWP的方向。遗传特征也表明，韩国济州岛可能作为一个过渡区的传播。黑潮驱动的NWP中的Thunbergii，从而促进随后向北输送到日本海和黄渤海。主要结论S. thunbergii的种群遗传同质性主要由洋流而不是古气候事件构成。我们的研究说明了一个重要的海洋地理的情况下，沿海水动力因素如何有助于人口的连通性和地理变化的遗传多样性的海洋生物没有远洋阶段。
AimOceanic currents are among the most pervasive hydrodynamic features in shaping community dynamics, population connectivity and phylogeographical structure of intertidal species. Here, we test whether population structure and biogeographical gradients of genetic diversity in the brown algaSargassum thunbergiiare correlated with oceanic currents in the north‐west Pacific (NWP).LocationNorth‐west Pacific (25.07°N–43.36°N).MethodsNuclear internal transcribed spacer‐2 and mitochondrialcox3 sequences were obtained from 835 and 810 individuals ofS. thunbergiirespectively. Parsimony networks and phylogenetic trees (maximum parsimony and Bayesian inference) were constructed to evaluate phylogeographical structure. PairwiseFSTestimates and analyses of molecular variance (AMOVA) at various hierarchical levels (latitude, longitude, marine provinces, biogeographical basins and zoogeographical zones) were conducted to elucidate population genetic differentiation.migratesoftware was used to estimate the number of migrants between adjacent populations.ResultsSeveral lines of evidence indicate thatS. thunbergiiis characterized by shallow population structure. Geographical distances do not correlate with population pairwise genetic differentiations. The corridor/stepping‐stone model‐based coalescent analyses reveal high levels of asymmetric gene flow amongS. thunbergiipopulations, with the numbers of migrants largely corresponding to the directions of oceanic current systems in the NWP. Genetic signatures also indicate that Jeju Island, Korea might act as a transition zone for dispersal ofS. thunbergiiin the NWP driven by the Kuroshio Current, thus facilitating subsequent transportation northward into the Sea of Japan and the Yellow‐Bohai Sea.Main conclusionsPopulation genetic homogeneity inS. thunbergiiwas mainly structured by oceanic currents rather than palaeoclimatic events. Our study illustrates an important phylogeographical case of how coastal hydrodynamic factors contributed to population connectivity and geographical shifts of genetic diversity for marine organisms without a pelagic stage.