Pediludiella daitoensis gen. et sp. nov. (Scenedesmaceae, Chlorophyceae), a large coccoid green alga isolated from a Loxodes ciliate
Pediludiella daitoensis gen. et sp. nov. (Scenedesmaceae, Chlorophyceae), a large coccoid green alga isolated from a Loxodes ciliate
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DOI：
10.1038/s41598-020-57423-x
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发表时间：
2020-01
影响因子：
4.6
通讯作者：
R. Hoshina;Masashi M. Hayakawa;Mayumi Kobayashi;R. Higuchi;T. Suzaki
中科院分区：
文献类型：
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作者：
R. Hoshina;Masashi M. Hayakawa;Mayumi Kobayashi;R. Higuchi;T. Suzaki
淡水原生生物通常在其细胞内含有单细胞绿色藻类。在纤毛虫中，可能是因为宿主细胞体积大，而藻球体体积小，一个宿主细胞通常包含一百多个藻细胞。在对日本南大东岛的原生生物进行调查时，发现了一种绿色的Loxodesciliate（Loxodida，Karyorelictea），其中含有一至两打非常大的球藻。我们对其中一种藻类进行了分离，并对其特性进行了详细的分析。一个小亚基（SSU）rDNA同源性表明Pseudodidymocystisspecies（Scenedesmaceae，Chlorophyceae）是最接近的分类单元，虽然它是清楚地从这39个或更多不同的网站（包括差距）分开。SSU rRNA结构分析表明，这些位移包括8个补偿性碱基变化（CBCs）和7个半CBCs。因此，我们得出结论，这是属于一个单独的属，并将其描述为Pediludiella daitoensisgen。et sp. nov.分离培养的大东拟步行虫形态近似球形，直径可达30 μm。叶绿体呈周向排列，常分裂伸长。细胞通常空泡化，具有网状细胞质，外观类似于足球（足球），这反映在属名中。
Freshwater protists often harbor unicellular green algae within their cells. In ciliates, possibly because of large host cell sizes and the small size of algal coccoids, a single host cell typically contains more than a hundred algal cells. While surveying such algae-bearing protists on Minami Daito Jima Island in Japan, we found a greenLoxodesciliate (Loxodida, Karyorelictea) that contained one or two dozens of very large coccoid algae. We isolated one of these algae and analyzed its characteristics in detail. A small subunit (SSU) rDNA phylogeny indicatedPseudodidymocystisspecies (Scenedesmaceae, Chlorophyceae) to be the taxon closest to the alga, although it was clearly separated from this by 39 or more different sites (inclusive of gaps). SSU rRNA structure analyses indicated that these displacements included eight compensatory base changes (CBCs) and seven hemi-CBCs. We therefore concluded that this alga belongs to a separate genus, and described it asPediludiella daitoensisgen. et sp. nov. The shape of the isolated and culturedP.daitoensiswas nearly spherical and reached up to 30 µm in diameter. Chloroplasts were arranged peripherally and often split and elongated. Cells were often vacuolated and possessed a net-like cytoplasm that resembled a football (soccer ball) in appearance, which was reflected in the genus name.