Sorbonne Universités, UPMC Université Paris 06, CNRS, UMR7144, Station Biologique de Roscoff, Roscoff, France.
Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor. Camino La Pirámide 5750, Huechuraba, Santiago, Chile.
Sci Rep. 2017 Oct 25;7(1):14019. doi: 10.1038/s41598-017-12412-5.
Prasinophytes are a paraphyletic group of nine lineages of green microalgae that are currently classified either at the class or order level or as clades without formal taxonomic description. Prasinophyte clade VII comprises picoplanktonic algae that are important components of marine phytoplankton communities, particularly in moderately oligotrophic waters. Despite first being cultured in the 1960s, this clade has yet to be formally described. Previous phylogenetic analyses using the 18S rRNA gene divided prasinophyte clade VII into three lineages, termed A, B and C, the latter formed by a single species, Picocystis salinarum, that to date has only been found in saline lakes. Strains from lineages A and B cannot be distinguished by light microscopy and have very similar photosynthetic pigment profiles corresponding to the prasino-2A pigment group. We obtained phenotypic and genetic data on a large set of prasinophyte clade VII culture strains that allowed us to clarify the taxonomy of this important marine group. We describe two novel classes, the Picocystophyceae and the Chloropicophyceae, the latter containing two novel genera, Chloropicon and Chloroparvula, and eight new species of marine picoplanktonic green algae.
原绿藻是一个由九个绿藻谱系组成的并系群，目前被分类为纲或目水平，或者作为没有正式分类描述的进化枝。原绿藻进化枝 VII 包括微小型浮游藻类，它们是海洋浮游植物群落的重要组成部分，特别是在中度贫营养水域中。尽管早在 20 世纪 60 年代就已经被培养，但这个进化枝尚未被正式描述。先前使用 18S rRNA 基因进行的系统发育分析将原绿藻进化枝 VII 分为三个谱系，称为 A、B 和 C，后者由一个单一的物种 Picocystis salinarum 组成，迄今为止只在盐湖中发现。谱系 A 和 B 的菌株不能通过光学显微镜区分，并且具有非常相似的光合作用色素谱，对应于原绿藻 2A 色素群。我们获得了大量原绿藻进化枝 VII 培养菌株的表型和遗传数据，这使我们能够澄清这个重要海洋群体的分类。我们描述了两个新的类群，即 Picocystophyceae 和 Chloropicophyceae，后者包含两个新的属，Chloropicon 和 Chloroparvula，以及八个新的海洋微小型浮游绿藻物种。
