Laboratory of Protistology and Aquatic Ecology, Biology Department, Ghent University, B-9000 Ghent, Belgium.
Proc Natl Acad Sci U S A. 2010 Jul 20;107(29):12952-7. doi: 10.1073/pnas.1001380107. Epub 2010 Jul 6.
The role of geographic isolation in marine microbial speciation is hotly debated because of the high dispersal potential and large population sizes of planktonic microorganisms and the apparent lack of strong dispersal barriers in the open sea. Here, we show that gene flow between distant populations of the globally distributed, bloom-forming diatom species Pseudo-nitzschia pungens (clade I) is limited and follows a strong isolation by distance pattern. Furthermore, phylogenetic analysis implies that under appropriate geographic and environmental circumstances, like the pronounced climatic changes in the Pleistocene, population structuring may lead to speciation and hence may play an important role in diversification of marine planktonic microorganisms. A better understanding of the factors that control population structuring is thus essential to reveal the role of allopatric speciation in marine microorganisms.
地理隔离在海洋微生物物种形成中的作用备受争议，因为浮游微生物具有很强的扩散能力和较大的种群规模，而开阔海域显然缺乏强大的扩散屏障。在这里，我们表明，全球分布的形成水华的硅藻物种 Pseudo-nitzschia pungens（I 类群）的远距离种群之间的基因流动是有限的，并且遵循强烈的距离隔离模式。此外，系统发育分析表明，在适当的地理和环境条件下，如更新世剧烈的气候变化，种群结构可能导致物种形成，因此可能在海洋浮游微生物的多样化中发挥重要作用。因此，更好地了解控制种群结构的因素对于揭示海洋微生物的异域物种形成的作用至关重要。
