Moore Jenna M, Carvajal Jose I, Rouse Greg W, Wilson Nerida G
Florida Museum of Natural History University of Florida Gainesville Florida.
Scripps Institution of Oceanography UCSD La Jolla California.
Ecol Evol. 2018 Oct 12;8(21):10621-10633. doi: 10.1002/ece3.4551. eCollection 2018 Nov.
The Antarctic Circumpolar Current (ACC) connects benthic populations by transporting larvae around the continent, but also isolates faunas north and south of the Antarctic Convergence. We test circumpolar panmixia and dispersal across the Antarctic Convergence barrier in the benthic sea star .
The Southern Ocean and south Atlantic Ocean, with comprehensive sampling including the Magellanic region, Scotia Arc, Antarctic Peninsula, Ross Sea, and East Antarctica.
The cytochrome c oxidase subunit I (COI) gene ( = 285) and the internal transcribed spacer region 2 (ITS2; = 33) were sequenced. We calculated haplotype networks for each genetic marker and estimated population connectivity and the geographic distribution of genetic structure using Φ for COI data.
is a single circum-Antarctic species with instances of gene flow between distant locations. Despite the homogenizing potential of the ACC, population structure is high (Φ = 0.5236), and some subpopulations are genetically isolated. Genetic breaks in the Magellanic region do not align with the Antarctic Convergence, in contrast with prior studies. Connectivity patterns in East Antarctic sites are not uniform, with some regional isolation and some surprising affinities to the distant Magellanic and Scotia Arc regions.
Despite gene flow over extraordinary distances, there is strong phylogeographic structuring and genetic barriers evident between geographically proximate regions (e.g., Shag Rocks and South Georgia). Circumpolar panmixia is rejected, although some subpopulations show a circumpolar distribution. Stepping-stone dispersal occurs within the Scotia Arc but does not appear to facilitate connectivity across the Antarctic Convergence. The patterns of genetic connectivity in Antarctica are complex and should be considered in protected area planning for Antarctica.
南极绕极流（ACC）通过在南极大陆周围输送幼体连接底栖生物种群，但同时也隔离了南极辐合带南北的动物区系。我们测试了底栖海星在南极绕极的随机交配情况以及跨越南极辐合带屏障的扩散情况。
南大洋和南大西洋，全面采样包括麦哲伦地区、斯科舍弧、南极半岛、罗斯海和东南极洲。
对细胞色素c氧化酶亚基I（COI）基因（n = 285）和内部转录间隔区2（ITS2；n = 33）进行测序。我们为每个遗传标记计算单倍型网络，并使用COI数据的Φ估计种群连通性和遗传结构的地理分布。
是一个单一的环南极物种，在遥远地点之间存在基因流动的实例。尽管南极绕极流具有使种群同质化的潜力，但种群结构程度较高（Φ = 0.5236），一些亚种群在遗传上是隔离的。与先前的研究相反，麦哲伦地区的遗传间断与南极辐合带不一致。东南极洲地点的连通性模式并不统一，存在一些区域隔离以及与遥远的麦哲伦和斯科舍弧地区一些令人惊讶的亲缘关系。
尽管存在远距离的基因流动，但在地理上相邻的区域（如沙格岩和南乔治亚岛）之间仍存在明显的系统发育结构和遗传屏障。虽然一些亚种群呈现环南极分布，但环南极随机交配的情况被否定。踏脚石式扩散发生在斯科舍弧内，但似乎并未促进跨越南极辐合带的连通性。南极洲的遗传连通性模式很复杂，在南极洲保护区规划中应予以考虑。
