Palacký University Olomouc, Faculty of Sciences, Department of Botany, Olomouc, Czech Republic.
Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden.
Nat Commun. 2024 Mar 8;15(1):2122. doi: 10.1038/s41467-024-46459-6.
Speciation is a continuous process driven by genetic, geographic, and ecological barriers to gene flow. It is widely investigated in multicellular eukaryotes, yet we are only beginning to comprehend the relative importance of mechanisms driving the emergence of barriers to gene flow in microbial populations. Here, we explored the diversification of the nearly ubiquitous soil cyanobacterium Microcoleus. Our dataset consisted of 291 genomes, of which 202 strains and eight herbarium specimens were sequenced for this study. We found that Microcoleus represents a global speciation continuum of at least 12 lineages, which radiated during Eocene/Oligocene aridification and exhibit varying degrees of divergence and gene flow. The lineage divergence has been driven by selection, geographical distance, and the environment. Evidence of genetic divergence and selection was widespread across the genome, but we identified regions of exceptional differentiation containing candidate genes associated with stress response and biosynthesis of secondary metabolites.
物种形成是一个由遗传、地理和生态障碍驱动的连续过程，阻止基因流动。它在多细胞真核生物中被广泛研究，但我们才刚刚开始理解推动微生物种群中基因流动障碍出现的机制的相对重要性。在这里，我们探讨了几乎无处不在的土壤蓝细菌微孢藻的多样化。我们的数据集包括 291 个基因组，其中 202 株和 8 个标本为本次研究进行了测序。我们发现，微孢藻代表了一个至少有 12 个谱系的全球物种形成连续体，它们在始新世/渐新世干旱化期间辐射，表现出不同程度的分化和基因流动。谱系分化是由选择、地理距离和环境驱动的。遗传分化和选择的证据广泛存在于整个基因组中，但我们发现了一些具有特殊分化的区域，其中包含与应激反应和次生代谢物生物合成相关的候选基因。
