Viricel Amélia, Rosel Patricia E
Department of Biology, University of Louisiana at Lafayette, Billeaud Hall, 300 E. St. Mary Boulevard, Lafayette, LA, 70504, USA; National Marine Fisheries Service, Southeast Fisheries Science Center, 646 Cajundome Boulevard, Lafayette, LA, 70506, USA; Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS, Université de La Rochelle, 2 rue Olympe de Gouges, 17000, La Rochelle, France.
Mol Ecol. 2014 Oct;23(20):5018-35. doi: 10.1111/mec.12923. Epub 2014 Oct 8.
Recent molecular studies have shown that highly mobile species with continuous distributions can exhibit fine-scale population structure. In this context, we assessed genetic structure within a marine species with high dispersal potential, the Atlantic spotted dolphin (Stenella frontalis). Using 19 microsatellite loci and mitochondrial control region sequences, population structure was investigated in the western North Atlantic, the Gulf of Mexico and the Azores Islands. Analyses of the microsatellite data identified four distinct genetic clusters, which were supported by the control region sequences. The highest level of divergence was seen between two clusters corresponding to previously described morphotypes that inhabit oceanic and shelf waters. The combined morphological and genetic evidence suggests these two lineages are on distinct evolutionary trajectories and could be considered distinct subspecies despite their parapatry. Further analysis of the continental shelf cluster resulted in three groups: animals inhabiting shelf waters in the western North Atlantic, the eastern Gulf of Mexico and the western Gulf of Mexico. Analyses of environmental data indicate the four genetic clusters inhabit distinct habitats in terms of depth and sea surface temperature. Contemporary dispersal rate estimates suggest all of these populations should be considered as distinct management units. Conversely, no significant genetic differentiation was observed between S. frontalis from offshore waters of the western North Atlantic and the Azores, which are separated by approximately 4500 km. Overall, the hierarchical structure observed within the Atlantic spotted dolphin shows that the biogeography of the species is complex because it is not shaped solely by geographic distance.
近期的分子研究表明，具有连续分布的高流动性物种可能呈现出精细尺度的种群结构。在此背景下，我们评估了具有高扩散潜力的海洋物种——大西洋斑点海豚（Stenella frontalis）的遗传结构。利用19个微卫星基因座和线粒体控制区序列，对北大西洋西部、墨西哥湾和亚速尔群岛的种群结构进行了研究。微卫星数据分析确定了四个不同的遗传簇，这得到了控制区序列的支持。在对应于先前描述的栖息于大洋水域和陆架水域的形态型的两个簇之间，观察到了最高水平的分化。形态学和遗传学证据相结合表明，这两个谱系处于不同的进化轨迹，尽管它们分布相邻，但可被视为不同的亚种。对大陆架簇的进一步分析产生了三个组：栖息于北大西洋西部陆架水域、墨西哥湾东部和墨西哥湾西部的动物。环境数据分析表明，这四个遗传簇在深度和海表温度方面栖息于不同的栖息地。当代扩散率估计表明，所有这些种群都应被视为不同的管理单元。相反，在被约4500公里隔开的北大西洋西部近海水域的大西洋斑点海豚和亚速尔群岛的海豚之间，未观察到显著的遗传分化。总体而言，在大西洋斑点海豚中观察到的层次结构表明，该物种的生物地理学很复杂，因为它并非仅由地理距离塑造。
