Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
Genomics Research Center, Academia Sinica, Taipei, Taiwan.
Sci Rep. 2019 Sep 20;9(1):13669. doi: 10.1038/s41598-019-50123-1.
Ciliates are unicellular eukaryotes known for their cellular complexity and wide range of natural habitats. How they adapt to their niches and what roles they play in ecology remain largely unknown. The genus Tetrahymena is among the best-studied groups of ciliates and one particular species, Tetrahymena thermophila, is a well-known laboratory model organism in cell and molecular biology, making it an excellent candidate for study in protist ecology. Here, based on cytochrome c oxidase subunit I (COX1) gene barcoding, we identify a total of 19 different putative Tetrahymena species and two closely related Glaucoma lineages isolated from distinct natural habitats, of which 13 are new species. These latter include 11 Tetrahymena species found in the bladder traps of Utricularia plants, the most species-rich and widely distributed aquatic carnivorous plant, thus revealing a previously unknown but significant symbiosis of Tetrahymena species living among the microbial community of Utricularia bladder traps. Additional species were collected using an artificial trap method we have developed. We show that diverse Tetrahymena species may live even within the same habitat and that their populations are highly dynamic, suggesting that the diversity and biomass of species worldwide is far greater than currently appreciated.
纤毛虫是单细胞真核生物，以其细胞复杂性和广泛的自然栖息地而闻名。它们如何适应各自的小生境以及在生态系统中扮演什么角色，在很大程度上仍然未知。四膜虫属是研究最为深入的纤毛虫类群之一，其中一种特殊的物种——嗜热四膜虫，是细胞和分子生物学领域著名的实验室模式生物，因此非常适合用于原生动物生态学的研究。在这里，我们基于细胞色素 c 氧化酶亚基 I（COX1）基因条码，总共鉴定出了 19 种不同的拟四膜虫物种和 2 种来自不同自然栖息地的密切相关的 Glaucoma 谱系，其中 13 种是新物种。这些新物种包括在狸藻类植物的膀胱陷阱中发现的 11 种四膜虫物种，狸藻类植物是最具物种多样性和广泛分布的水生食虫植物，这揭示了以前未知但重要的四膜虫物种与狸藻类植物膀胱陷阱中的微生物群落之间的共生关系。其他物种是使用我们开发的人工陷阱方法收集的。我们表明，不同的四膜虫物种甚至可能生活在同一栖息地中，并且它们的种群具有高度动态性，这表明全球范围内物种的多样性和生物量远远超过目前的认识。
