Waters J M, Roy M S
Department of Zoology, University of Otago, PO Box 56, Dunedin, New Zealand.
Mol Ecol. 2004 Sep;13(9):2797-806. doi: 10.1111/j.1365-294X.2004.02282.x.
New Zealand's (NZ) geographical isolation, extensive coastline and well-characterized oceanography offer a valuable system for marine biogeographical research. Here we use mtDNA control region sequences in the abundant endemic sea-star Patiriella regularis to test the following literature-based predictions: that coastal upwelling disrupts north-south gene flow and promotes population differentiation (hypothesis 1); and that an invasive Tasmanian population of the species was introduced anthropogenically from southern New Zealand (hypothesis 2). We sequenced 114 samples from 22 geographical locations, including nine sites from North Island, nine from South Island, one from Stewart Island and three from Tasmania. Our analysis of these sequences revealed an abundance of shallow phylogenetic lineages within P. regularis (68 haplotypes, mean divergence 0.9%). We detected significant genetic heterogeneity between pooled samples from northern vs. southern New Zealand (FST = 0.072; P = 0.0002), consistent with the hypothesis that upwelling disrupts gene flow between these regions (hypothesis 1). However, we are currently unable to rule out the alternative hypothesis that Cook Strait represents a barrier to dispersal (North Island vs. South Island; FST = 0.031; P = 0.0467). The detection of significant spatial structure in NZ samples is consistent with restricted gene flow, and the strong structure evident in northern NZ may be facilitated by distinct ocean current systems. Four shared haplotypes and nonsignificant differentiation (FST = 0.025; P = 0.2525) between southern New Zealand and Tasmanian samples is consistent with an anthropogenic origin for the latter population (hypothesis 2).
新西兰的地理隔离、漫长的海岸线以及特征明确的海洋ography为海洋生物地理学研究提供了一个宝贵的系统。在这里，我们使用丰富的地方性海星Patiriella regularis中的线粒体DNA控制区序列来检验以下基于文献的预测：沿海上升流会破坏南北基因流动并促进种群分化（假设1）；以及该物种的塔斯马尼亚入侵种群是人为从新西兰南部引入的（假设2）。我们对来自22个地理位置的114个样本进行了测序，包括来自北岛的9个地点、南岛的9个地点、斯图尔特岛的1个地点和塔斯马尼亚的3个地点。我们对这些序列的分析揭示了P. regularis内部存在大量浅分支系统发育谱系（68个单倍型，平均分歧度0.9%）。我们检测到新西兰北部与南部合并样本之间存在显著的遗传异质性（FST = 0.072；P = 0.0002），这与上升流破坏这些区域之间基因流动的假设（假设1）一致。然而，我们目前无法排除另一种假设，即库克海峡是扩散的障碍（北岛与南岛；FST = 0.031；P = 0.0467）。在新西兰样本中检测到显著的空间结构与基因流动受限一致，而在新西兰北部明显的强烈结构可能是由不同的洋流系统促成的。新西兰南部和塔斯马尼亚样本之间有四个共享单倍型且分化不显著（FST = 0.025；P = 0.2525），这与后者种群的人为起源假设（假设2）一致。
