Ryšánek David, Hrčková Kristýna, Škaloud Pavel
Department of Botany, Faculty of Science, Charles University in Prague, Prague, Czech Republic.
Environ Microbiol. 2015 Mar;17(3):689-98. doi: 10.1111/1462-2920.12501. Epub 2014 Jun 3.
Despite considerable research attention during the last 10 years, the distribution and biogeography of protists remain as highly controversial issues. The presumably huge population sizes and unlimited dispersal capabilities should result in protist ubiquity. However, recent molecular investigations suggest that protist communities exhibit strong biogeographic patterns. Here, we examined the biogeographic pattern of a very common green algal genus Klebsormidium. We evaluated the geographic distribution of rbcL genotypes for 190 isolates sampled in six sampling regions located in Europe, North America and Asia. Measures of correlation between genetic and geographic distance matrices revealed a differential distribution pattern on two geographic levels. Globally, the populations were genetically homogeneous; locally, the genotypes were patchily distributed. We hypothesized that a local fine-scale structuring of genotypes may be caused by various ecological factors, in particular, by the habitat differentiation of particular genotypes. Our investigations also identified a large number of new, previously unrecognized lineages. A total of 44 genotypes were identified and more than 66% of these were reported for the first time.
尽管在过去十年中受到了大量的研究关注，但原生生物的分布和生物地理学仍然是极具争议的问题。据推测，原生生物庞大的种群规模和无限的扩散能力应使其无处不在。然而，最近的分子研究表明，原生生物群落呈现出强烈的生物地理模式。在此，我们研究了一种非常常见的绿藻属——鞘毛藻属的生物地理模式。我们评估了从欧洲、北美和亚洲六个采样区域采集的190个分离株的rbcL基因型的地理分布。遗传距离矩阵与地理距离矩阵之间的相关性分析揭示了两个地理层面上的差异分布模式。在全球范围内，种群在遗传上是同质的；在局部范围内，基因型呈斑块状分布。我们推测，基因型在局部的精细尺度结构可能是由各种生态因素造成的，特别是特定基因型的栖息地分化。我们的研究还发现了大量新的、以前未被识别的谱系。总共鉴定出44种基因型，其中超过66%是首次报道。
