Department of Biological Sciences, National University of Singapore, 10 Science Drive 4, 117555, Singapore; St. John's Island National Marine Laboratory (SJINML), Tropical Marine Science Institute (TMSI), National University of Singapore, 18 Kent Ridge Road, 119227, Singapore.
St. John's Island National Marine Laboratory (SJINML), Tropical Marine Science Institute (TMSI), National University of Singapore, 18 Kent Ridge Road, 119227, Singapore.
Harmful Algae. 2019 Jun;86:10-19. doi: 10.1016/j.hal.2019.04.010. Epub 2019 May 6.
Lyngbya majuscula is a marine filamentous cyanobacteria belonging to the family Oscillatoriaceae. Recent phylogenetic analyses of L. majuscula have reclassified a subset of this species into various genera such as Moorea, Okeania and Dapis. From the genus Moorea, Moorea producens is a toxic invasive cyanobacterium that produces bioactive secondary metabolites that can cause severe inflammation and blistering. Despite the global distribution of M. producens, little information is available on their origin, patterns of dispersal and population structure. In this study, the spatial population structure of M. producens was investigated using near-complete 16S rRNA sequences. Analysis of the global population of M. producens by Isolation by Distance and STRUCTURE revealed two significantly distinct cosmopolitan populations that were separated by a genetic break. Lineage-specific divergence estimates of 147 cyanobacterial taxa, based on a relaxed molecular clock indicated the first global emergence of M. producens during the Mesoarchean and a subsequent global recolonization during the Mesoproterozoic period. We conclude that the genetic discontinuity between both cosmopolitan populations is attributed to refugia associated with Proterozoic glacial cycles.
大巨 Lyngbya majuscula 是一种海洋丝状蓝藻，属于颤藻科。最近对大巨 Lyngbya majuscula 的系统发育分析将该物种的一部分重新分类为各种属，如 Moorea、Okeania 和 Dapis。从 Moorea 属中，Moorea producens 是一种有毒的入侵蓝藻，它产生具有生物活性的次生代谢物，可导致严重的炎症和水疱。尽管 Moorea producens 分布广泛，但关于其起源、扩散模式和种群结构的信息很少。在这项研究中，使用近完整的 16S rRNA 序列研究了 Moorea producens 的空间种群结构。通过距离隔离和 STRUCTURE 分析对 Moorea producens 的全球种群进行分析，揭示了两个明显不同的世界性种群，它们被遗传断裂隔开。基于松弛分子钟，对 147 种蓝细菌的种系特异性分歧估计表明，Moorea producens 的首次全球出现发生在中太古代，随后在元古代期间发生了全球再殖民化。我们得出结论，两个世界性种群之间的遗传不连续性归因于与元古代冰期相关的避难所。
