Gerbod D, Edgcomb V P, Noël C, Zenner L, Wintjens R, Delgado-Viscogliosi P, Holder M E, Sogin M L, Viscogliosi E
Institut Pasteur de Lille, INSERM Unité 547, France.
J Eukaryot Microbiol. 2001 Jul-Aug;48(4):498-504. doi: 10.1111/j.1550-7408.2001.tb00185.x.
The phylogenetic position of the trichomonad, Histomonas meleagridis was determined by analysis of small subunit rRNAs. Molecular trees including all identified parabasalid sequences available in data bases were inferred by distance, parsimony, and likelihood methods. All reveal a close relationship between H. meleagridis, and Dientamoeba fragilis. Moreover, small subunit rRNAs of both amoeboid species have a reduced G + C content and increased chain length relative to other parabasalids. Finally, the rRNA genes from H. meleagridis and D. fragilis share a recent common ancestor with Tritrichomonasfoetus, which exhibits a more developed cytoskeleton. This indicates that Histomonas and Dientamoeba secondarily lost most of the typical trichomonad cytoskeletal structures and hence, do not represent primitive morphologies. A global phylogeny of parabasalids revealed significant discrepancies with morphology-based classifications, such as the polyphyly of most of the parabasalid families and classes included in our study.
通过对小亚基核糖体RNA的分析确定了火鸡组织滴虫（Histomonas meleagridis）在系统发育中的位置。利用距离法、简约法和似然法推断出包含数据库中所有已鉴定的副基体序列的分子树。所有结果都显示火鸡组织滴虫与脆弱双核阿米巴（Dientamoeba fragilis）之间关系密切。此外，相对于其他副基体，这两种阿米巴样物种的小亚基核糖体RNA的G + C含量降低，链长增加。最后，火鸡组织滴虫和脆弱双核阿米巴的核糖体RNA基因与胎儿三毛滴虫（Tritrichomonas foetus）拥有一个最近的共同祖先，胎儿三毛滴虫具有更发达的细胞骨架。这表明组织滴虫和双核阿米巴在进化过程中次生地失去了大部分典型的滴虫细胞骨架结构，因此并不代表原始形态。副基体的全球系统发育显示出与基于形态学的分类存在显著差异，例如我们研究中所包含的大多数副基体科和纲的多系性。
