Trachyrhizium urniformis n. g., n. sp., a Novel Marine Filose Thecate Amoeba Related to a Cercozoan Environmental Clade (Novel Clade 4)
Trachyrhizium urniformis n. g., n. sp., a Novel Marine Filose Thecate Amoeba Related to a Cercozoan Environmental Clade (Novel Clade 4)
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DOI：
10.1111/jeu.12319
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发表时间：
2016-11
影响因子：
2.2
通讯作者：
Takashi Shiratori;K. Ishida
中科院分区：
文献类型：
--
作者：
Takashi Shiratori;K. Ishida
从日本冲绳Agenashiku岛的海洋沉积物样品中分离到一种新的鞭毛虫变形虫--尾根变形虫(TrachyRhum urniformis n.g，n.sp.)。我们进行了光镜和电子显微镜观察，并利用该分离株的小亚单位核糖体RNA基因进行了分子系统发育分析。毛滴虫的细胞呈球形，被一层薄的膜覆盖，膜上有一个宽阔的圆形孔。分枝和偶尔网结的带有小颗粒的丝状足细胞从孔中出现。颗粒在丝状孔道中双向运输。透射电子显微镜显示，毛滴虫细胞内有染色质永久性凝集的细胞核、高尔基体、微体、管状隆起的线粒体和挤出体。一些形态和超微结构特征(囊膜和核的存在，染色质永久凝聚)与丝状毛滴虫相似。在系统发育分析中，在统计支持较弱的情况下，将羊毛虫归入丝状丝虫亚纲，并形成一个含有两个序列的分支，构成一个尾虫环境支系--新支系4。根据形态和超微结构信息以及系统发育分析的结果，我们将其归入丝状丝虫亚纲。
A novel cercozoan filose thecate amoeba, Trachyrhizium urniformis n. g., n. sp., was isolated from a marine sediment sample collected at Agenashiku Island, Okinawa, Japan. We performed light and electron microscopic observations, and a molecular phylogenetic analysis using the small subunit ribosomal RNA gene of the isolate. Cells of T. urniformis are spherical in shape and are covered by a thin theca possessing a wide rounded aperture. Branching and occasionally anastomosing filopodia with small granules emerge from the aperture. The granules are transported in the filopodia bidirectionally. Transmission electron microscopy showed that cells of T. urniformis possess nucleus with permanently condensed chromatin, Golgi apparatuses, microbodies, mitochondria with tubular cristae, and extrusomes. Several morphological and ultrastructural features of T. urniformis (the presence of thecae and nucleus with permanently condensed chromatin) show similarities with those of Thecofilosea. In a phylogenetic analysis, T. urniformis included in Thecofilosea with weak statistical supports and formed a clade with two sequences that constitutes a cercozoan environmental clade, novel clade 4. On the basis of morphological and ultrastructural information and the results of the phylogenetic analysis, we propose T. urniformis as a new member of class Thecofilosea.