Department of Integrative Biology, University of Guelph, ON, Canada.
Eur J Protistol. 2012 Nov;48(4):305-13. doi: 10.1016/j.ejop.2012.04.001. Epub 2012 May 16.
Most recent studies of geographic distribution of microbial eukaryotes have focused on marine rather than freshwater protists. Here, we used the freshwater peritrich ciliate Carchesium polypinum to quantify the degree of genetic diversity of four closely related and previously described lineages and to determine whether patterns of genetic differentiation showed geographic partitioning. Using an expanded dataset of 100 isolates and employing the mitochondrial marker cytochrome oxidase c subunit I (cox-1), we enriched the 6 previously identified clades of Carchesium polypinum. We found a large degree of geographic overlap among the different clades (e.g. to the level of range of sampling), but also a spatially restricted clade (e.g. to the level of one river basin). Furthermore, we present evidence of a clear geographic separation in one of the lineages with Canadian and North Carolinian isolates grouping in two distinct clusters.
最近对微生物真核生物地理分布的研究主要集中在海洋而不是淡水原生动物上。在这里，我们使用淡水缘毛目纤毛虫 Carchesium polypinum 来量化四个密切相关且先前已描述的谱系的遗传多样性程度，并确定遗传分化模式是否表现出地理分区。使用包含 100 个分离株的扩展数据集，并采用线粒体标记细胞色素氧化酶 c 亚基 I（cox-1），我们丰富了 Carchesium polypinum 的 6 个先前确定的进化枝。我们发现不同进化枝之间存在很大程度的地理重叠（例如，达到采样范围的水平），但也存在空间上受限的进化枝（例如，达到一个流域的水平）。此外，我们还提供了一个明确的地理分离的证据，在一个具有加拿大和北卡罗来纳分离株的谱系中，两个不同的聚类。
