Laboratory of Cellular and Molecular Protistology, Zoological Institute RAS, Universitetskaya nab, St Petersburg, Russia.
Int J Syst Evol Microbiol. 2021 Nov;71(11). doi: 10.1099/ijsem.0.005094.
Amoebozoan parasites of arrow-worms (Chaetognatha) were isolated from their hosts living in plankton of the Bay of Villefranche (Mediterranean Sea). Based on the light microscopic characters, the amoebae were identified as (Grassi, 1881) by their limax locomotive form and due to the presence of the intracellular symbiont, , surrounded by a layer of pigment granules. Sequences of the 18S rRNA gene of both and its symbiont were obtained for the first time. The molecular phylogenetic analyses of 18S rRNA gene placed within the genus , a taxon also characterized by the presence of a symbiont, known as -like organism (PLO). The 18S rRNA gene sequence of from grouped with the sequences of 18S rRNA genes of PLOs from and . The first photo documentation of the light microscopic features of , such as locomotive form, the morphology of the nucleus and have been provided. The new results support the affinity of with the family Paramoebidae suggested previously based on the presence of PLO. In contrast to , typical members of Paramoebidae ( and ) have a flattened, dactylopodial locomotive form. This discrepancy in morphology can be explained by the obligate parasitic lifestyle of .
箭虫（ Chaetognatha ）的变形虫寄生虫从其生活在滨海湾浮游生物中的宿主中分离出来（地中海）。根据光镜特征，这些变形虫被鉴定为 （Grassi，1881），其具有 Limax 运动形式，并且由于存在细胞内共生体 ，被一层色素颗粒包围。首次获得了 18S rRNA 基因和其共生体的序列。18S rRNA 基因的分子系统发育分析将 归入属 ，该分类群也以共生体的存在为特征，称为类似生物体（PLO）。来自 和 的 PLO 的 18S rRNA 基因序列与 从 获得的 18S rRNA 基因序列聚在一起。提供了 光镜特征的首次照片记录，例如运动形式，核形态和 。新的结果支持先前基于 PLO 存在而提出的 与 Paramoebidae 科的亲和力。与典型的 Paramoebidae 成员（ 和 ）相比， 具有扁平的，指状运动形式。这种形态上的差异可以通过 的专性寄生生活方式来解释。
