Key Laboratory of Aquaculture Diseases Control, Ministry of Agriculture, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
University of Chinese Academy of Sciences, Beijing, 10049, China.
Parasitol Res. 2019 Jun;118(6):1689-1699. doi: 10.1007/s00436-019-06303-z. Epub 2019 Apr 11.
We describe the type species of a novel genus of microsporidian parasite, Pseudokabatana alburnus n. gen. n. sp., infecting the liver of topmouth culter, Culter alburnus Basilewsky, 1855, from Lake Poyang off Xingzi county, Jiangxi Province, China. The parasite elicits formation of spherical xenomas of up to 1.2 mm in diameter containing all observed life stages from early merogonal plasmodia to mature spores contained within the cytoplasm of host hepatocytes. Merogonal plasmodia existed in direct contact with the host cytoplasm and contained up to 20 visible nuclei. Plasmotomy of the multinucleate plasmodium led to formation of uninucleate cells in which the nucleus underwent further division to form bi-nucleate presporonts, sporonts (defined by cells with a thickened endospore) and eventually sporoblasts (containing pre-cursors of the spore extrusion apparatus). Mature spores were pyriform and monokaryotic, measuring 2.3 ± 0.19 μm long and 1.3 ± 0.10 μm wide. Spores possessed a bipartite polaroplast and 5-6 coils of a polar filament, in a single rank. The obtained partial SSU rRNA gene sequence, 1383 bp in length, did not match any of microsporidia available in GenBank. SSU rDNA-based phylogenetic analysis indicated a new taxon branching with Kabatana rondoni, a parasite infecting the skeletal muscle of Gymnorhamphichthys rondoni from the Amazon River. Due to different host and tissue tropism, the novel taxon did not fit the diagnostic criteria for the genus Kabatana. Further, based on SSU rDNA-inferred phylogenetic analyses, different ultrastructural features of developmental stages, and ecological considerations, a new genus Pseudokabatana and type species Pseudokabatana alburnus n. sp. was erected for the parasite in topmouth culter.
我们描述了一种新型微孢子虫寄生虫的模式种，即假卡巴塔纳氏鱼白体虫，新属新种，感染来自中国江西省星子县鄱阳湖的翘嘴红鲌，Culter alburnus Basilewsky，1855。寄生虫引起的肝球蚴直径可达 1.2 毫米，包含从早期多核质原生质团到成熟孢子的所有观察到的生活阶段，这些孢子位于宿主肝细胞的细胞质内。多核质原生质团与宿主细胞质直接接触，包含多达 20 个可见核。多核质原生质团的质裂导致形成单核细胞，其中核进一步分裂形成二核前孢子、孢子和最终的孢子母细胞（包含孢子挤出装置的前体）。成熟的孢子呈梨形，单核，长 2.3±0.19μm，宽 1.3±0.10μm。孢子具有二分的极质体和 5-6 圈的极丝，呈单列排列。获得的部分 SSU rRNA 基因序列长 1383bp，与 GenBank 中可用的微孢子虫没有任何匹配。基于 SSU rDNA 的系统发育分析表明，一个新的分类群与感染亚马逊河 Gymnorhamphichthys rondoni 骨骼肌的卡巴塔纳氏鱼卡巴塔纳氏鱼亲缘关系最近。由于宿主和组织趋向性不同，这个新的分类群不符合卡巴塔纳氏鱼属的诊断标准。此外，基于 SSU rDNA 推断的系统发育分析、不同的发育阶段的超微结构特征和生态考虑，为该寄生虫在翘嘴红鲌中建立了一个新属假卡巴塔纳氏鱼属和模式种假卡巴塔纳氏鱼白体虫，新种。
