A new species of the “proteus-type” naked amoebae (large cells with discrete tubular pseudopodia) was isolated from tree bark sample of a birch tree in the surrounding of Kislovodsk town, Russia and named Polychaos centronucleolus n. sp. (Amoebozoa, Tubulinea). Amoebae of this species have a filamentous cell coat and a nucleus with a central compact nucleolus. This type of nucleolar organization has not been previously known for the genus Polychaos. A sequence of the 18S rRNA gene of this strain was obtained using whole genome amplification of DNA from the single amoeba cell, followed by NGS sequencing. The analysis of molecular data robustly groups this species with Polychaos annulatum within the family Hartmannellidae. Our results, together with the results of our previous studies, show that the taxonomic assignment of “proteus-type” amoebae species is becoming increasingly complex, and the taxonomic characters that can be used to classify these organisms are becoming more shadowed.

从俄罗斯基斯洛沃茨克镇周围的一棵白桦树的树皮样品中分离出一种新的“变形蛋白”型裸变形虫（大细胞，具伪管状假足），并将其命名为“ Polychaos centronucleolus n”。sp。（Amoebozoa，Tubulinea）。该物种的变形虫具有丝状细胞被膜和具有中央紧密核仁的核。这种类型的核仁组织以前不为Polychaos属所知。通过从单个变形虫细胞中扩增DNA的全基因组，然后进行NGS测序，获得了该菌株18S rRNA基因的序列。分子数据分析将该物种与环斑羚紧密结合在一起在家庭Hartmannellidae中。我们的结果以及我们以前的研究结果表明，“变形型”变形虫物种的分类学分配变得越来越复杂，并且可用于对这些生物进行分类的分类学特征也变得越来越模糊。