School of Life Sciences, East China Normal University, Shanghai, 200241, China.
Department of Biology, University of Pisa, Via Luca Ghini 13, Pisa, 56126, Italy.
Sci Rep. 2020 Feb 28;10(1):3763. doi: 10.1038/s41598-020-60327-5.
An integrated approach considering both morphologic and molecular data is now required to improve biodiversity estimations and provide more robust systematics interpretations in hypotrichs, a highly differentiated group of ciliates. In present study, we document a new hypotrich species, Lamtostyla gui n. sp., collected from Chongming wetland, Shanghai, China, based on investigations using living observation, protargol staining, scanning and transmission electron microscopy, and gene sequencing. The new species is mainly recognized by having a short amphisiellid median cirral row composed of four cirri, three frontoventral cirri, three dorsal kinetids, four to eight macronuclear nodules, and small colorless cortical granules distributed as rosettes around dorsal bristles. Transmission electron microscope observation finds the associated microtubules of cirri and pharyngeal discs of L. gui are distinct from those in other hypotrichs. Morphogenesis of this species indicates that parental adoral membranelles retained intact or partial renewed is a potential feature to separate Lamtostyla granulifera-group and Lamtostyla lamottei-group. Phylogenetic analysis based on small subunit ribosomal RNA (rRNA) gene shows that this molecular marker is not useful to resolve phylogenetic relationships of the genus Lamtostyla, as well as many other hypotrichous taxa. We additionally characterize the internal transcribed spacers (ITS) region and the almost complete large subunit rRNA, which will be essential for future studies aimed at solving phylogenetic problems of Lamtostyla, or even the family Amphisiellidae. As a final remark, the critical screening of GenBank using ITS genes of our organism allows us to recognize a large amount of hypotrichous sequences have been misclassified as fungi. This observation suggests that hypotrichs could be frequently found in fungi-rich environment and overlooked by fungal specialists.
一种综合形态和分子数据的方法现在被要求提高生物多样性的估计，并为纤毛虫中的高度分化类群提供更稳健的系统发育解释。在本研究中，我们根据活体观察、蛋白银染色、扫描和透射电子显微镜以及基因测序的研究，记录了一种来自中国上海崇明湿地的新纤毛虫物种，即 Lamto-styla gui n. sp. 该新种主要通过具有短的两性内median cirral 列组成的四个纤毛、三个额腹侧纤毛、三个背动基体、四到八个大核小结和小的无色皮质颗粒呈玫瑰花形分布在背刚毛周围而被识别。透射电子显微镜观察发现 Lamto-styla gui 的纤毛和咽盘相关微管与其他纤毛虫不同。该物种的形态发生表明，亲代的顶纤毛完整保留或部分更新是将 Lamto-styla granulifera 组和 Lamto-styla lamottei 组分开的一个潜在特征。基于小亚基核糖体 RNA (rRNA) 基因的系统发育分析表明，这个分子标记对于解决 Lamto-styla 属以及许多其他纤毛虫类群的系统发育关系没有用处。我们还描述了内部转录间隔区（ITS）区域和几乎完整的大亚基 rRNA，这对于解决 Lamto-styla 甚至 Amphisiellidae 科的系统发育问题的未来研究将是必不可少的。最后，我们利用 ITS 基因对 GenBank 进行了关键筛选，结果表明大量纤毛虫序列被错误分类为真菌。这一观察结果表明，纤毛虫可能经常在真菌丰富的环境中被发现，而被真菌专家忽视。
