Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
Departamento de Biología Aplicada, Facultad de Ciencias Experimentales, Universidad de Miguel Hernandez, 03202, Elche, Spain.
Sci Rep. 2020 Oct 28;10(1):18453. doi: 10.1038/s41598-020-75303-2.
Attached or floating macroscopic cyanobacteria can be found in shallow waters and can be easily hand-collected, but their identification is often challenging due to their high morphological variability. In addition, many members of environmental samples lose their morphological adaptations under controlled conditions, making the integration of analyses of field populations and derived isolated cultures necessary in order to evaluate phenotypic plasticity for identification purposes. Therefore, in this study, twenty-nine macroscopic field samples were analyzed by Illumina sequencing and parallel optical microscopy. Some colonies showed the typical morphological characteristics of Rivularia biasolettiana, and others showed those of Rivularia haematites. However, other Rivularia-like colonies showed ambiguous morphologies, and some of them showed the phenotypic features of the new genus Cyanomargarita, which is virtually indistinguishable from Rivularia in the field. In all of the colonies, phylotype composition was highly heterogeneous, with abundances varying depending on the analyzed sample. Some colonies were dominated (97-99%) by a single phylotype, while in others, the percentage of the dominant phylotype decreased to approximately 50-60%. Surprisingly, the same dominant phylotype was found in R. biasolettiana and R. haematites colonies. The relationships between environmental and/or biological factors and morphological variability in these colonies are discussed.
附件或漂浮的宏观蓝藻可以在浅水中找到，并且可以很容易地用手收集，但由于其高度的形态变异性，它们的鉴定通常具有挑战性。此外，许多环境样本中的成员在受控条件下失去其形态适应，因此有必要将野外种群和衍生的分离培养物的分析相结合，以便为鉴定目的评估表型可塑性。因此，在这项研究中，通过 Illumina 测序和并行光学显微镜分析了 29 个宏观野外样本。一些菌落表现出 Rivularia biasolettiana 的典型形态特征，而另一些则表现出 Rivularia haematites 的形态特征。然而，其他类似 Rivularia 的菌落表现出模糊的形态，其中一些表现出新属 Cyanomargarita 的表型特征，在野外与 Rivularia 几乎无法区分。在所有的菌落中，基因型组成高度异质，丰度因分析样本而异。一些菌落由单一基因型主导（97-99%），而在其他菌落中，优势基因型的比例下降到约 50-60%。令人惊讶的是，相同的优势基因型在 R. biasolettiana 和 R. haematites 菌落中被发现。讨论了这些菌落中环境和/或生物因素与形态变异性之间的关系。
