Lack of genetic evidence for the subspeciation of Pisaster ochraceus (Echinodermata: Asteroidea) in the north-eastern Pacific Ocean
Lack of genetic evidence for the subspeciation of Pisaster ochraceus (Echinodermata: Asteroidea) in the north-eastern Pacific Ocean
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DOI：
10.1017/s0025315408000519
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发表时间：
2008-03-01
影响因子：
1.2
通讯作者：
Sanvicente-Anorve, Laura
中科院分区：
文献类型：
--
作者：
Frontana-Uribe, Sarita;De la Rosa-Velez, Jorge;Sanvicente-Anorve, Laura
提出了双鱼亚种的存在；一个位于北端（P. ochraceus ochraccus），另一个位于南端（Pisaster ochraceus segnis）。我们使用聚合酶链反应-限制性片段长度多态性- CO I和CO III线粒体基因来评估从加拿大温哥华到墨西哥下加利福尼亚州蓬塔圣卡洛斯的北美西海岸收集的126个样本的种群结构程度。通过分子方差分析和对原始数据集的蒙特卡罗模拟，对遗传结构进行了测试。系统地理格局是由最小跨越网络分析推导出来的。未检测到遗传结构。相反，从每个地点的单倍型频率可以看出，沿物种分布的遗传同质性很高。两个单倍型（P01和P05）在整个分布中占主导地位，由于它们在最小跨越网络中的中心位置，被认为是祖先。由于Pisaster ochraceus描绘了一个在定居前持续很长时间的浮游营养幼虫阶段，它似乎能够超越限制在Point Conception周围的其他物种的生物地理边界，从而保持其基因库的同质性。本研究的结果将P. ochraceus识别为单一种。
The existence of two Pisaster ochraceus subspecies has been proposed; one located northwards (P. ochraceus ochraccus) and the other southwards (Pisaster ochraceus segnis) from Point Conception. We used polymerase chain reaction - restriction fragment length polymorphism of the CO I and CO III mitochondrial genes to assess the degree of population structure from 126 samples collected along the western coast of North America, from Vancouver, Canada to Punta San Carlos, of Baja California, Mexico. The genetic structure was tested through molecular analysis of variance and by Monte Carlo simulations of the original data set. The phylogeographical pattern was deduced from a minimum spanning network analysis. No genetic structure was detected. Instead, a high degree of genetic homogeneity along the species distribution was evident from haplotype frequencies at each location. Two haplotypes, P01 and P05, were predominant along the distribution and were considered ancestral because of their central position in the minimum spanning network. Since Pisaster ochraceus depicts a planktotrophic larval stage with very long duration before settlement, it seems to be able to surpass the biogeographical boundary that limits other species around Point Conception, thereby maintaining homogeneity of its genetic pool. Results of this study recognize P. ochraceus as a single species.