Saenz-Agudelo Pablo, Dibattista Joseph D, Piatek Marek J, Gaither Michelle R, Harrison Hugo B, Nanninga Gerrit B, Berumen Michael L
Division of Biological and Environmental Science and Engineering, Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile.
Mol Ecol. 2015 Dec;24(24):6241-55. doi: 10.1111/mec.13471. Epub 2015 Dec 12.
Understanding the processes that shape patterns of genetic structure across space is a central aim of landscape genetics. However, it remains unclear how geographical features and environmental variables shape gene flow, particularly for marine species in large complex seascapes. Here, we evaluated the genomic composition of the two-band anemonefish Amphiprion bicinctus across its entire geographical range in the Red Sea and Gulf of Aden, as well as its close relative, Amphiprion omanensis endemic to the southern coast of Oman. Both the Red Sea and the Arabian Sea are complex and environmentally heterogeneous marine systems that provide an ideal scenario to address these questions. Our findings confirm the presence of two genetic clusters previously reported for A. bicinctus in the Red Sea. Genetic structure analyses suggest a complex seascape configuration, with evidence of both isolation by distance (IBD) and isolation by environment (IBE). In addition to IBD and IBE, genetic structure among sites was best explained when two barriers to gene flow were also accounted for. One of these coincides with a strong oligotrophic-eutrophic gradient at around 16-20˚N in the Red Sea. The other agrees with a historical bathymetric barrier at the straight of Bab al Mandab. Finally, these data support the presence of interspecific hybrids at an intermediate suture zone at Socotra and indicate complex patterns of genomic admixture in the Gulf of Aden with evidence of introgression between species. Our findings highlight the power of recent genomic approaches to resolve subtle patterns of gene flow in marine seascapes.
理解塑造空间遗传结构模式的过程是景观遗传学的核心目标。然而，地理特征和环境变量如何塑造基因流仍不清楚，特别是对于大型复杂海域中的海洋物种。在这里，我们评估了双带小丑鱼（Amphiprion bicinctus）在红海和亚丁湾整个地理范围内的基因组组成，以及其近亲阿曼小丑鱼（Amphiprion omanensis），后者是阿曼南部海岸特有的物种。红海和阿拉伯海都是复杂且环境异质的海洋系统，为解决这些问题提供了理想的场景。我们的研究结果证实了先前报道的红海双带小丑鱼存在两个遗传簇。遗传结构分析表明存在复杂的海域格局，有距离隔离（IBD）和环境隔离（IBE）的证据。除了IBD和IBE之外，当考虑到两个基因流障碍时，各地点之间的遗传结构得到了最好的解释。其中一个与红海16 - 20°N附近强烈的贫营养 - 富营养梯度相吻合。另一个与曼德海峡的历史深度障碍一致。最后，这些数据支持在索科特拉岛的中间缝合带存在种间杂交种，并表明亚丁湾存在复杂的基因组混合模式，有物种间基因渗入的证据。我们的研究结果突出了近期基因组方法在解析海洋景观中微妙基因流模式方面的作用。
