Silberman Jeffrey D, Collins Allen G, Gershwin Lisa-Ann, Johnson Patricia J, Roger Andrew J
Department of Microbiology, Immunology, and Molecular Genetics, University of California at Los Angeles, California, USA.
J Eukaryot Microbiol. 2004 Mar-Apr;51(2):246-52. doi: 10.1111/j.1550-7408.2004.tb00555.x.
Ellobiopsids are multinucleate protist parasites of aquatic crustaceans that possess a nutrient absorbing 'root' inside the host and reproductive structures that protrude through the carapace. Ellobiopsids have variously been affiliated with fungi, 'colorless algae', and dinoflagellates, although no morphological character has been identified that definitively allies them with any particular eukaryotic lineage. The arrangement of the trailing and circumferential flagella of the rarely observed bi-flagellated 'zoospore' is reminiscent of dinoflagellate flagellation, but a well-organized 'dinokaryotic nucleus' has never been observed. Using small subunit ribosomal RNA gene sequences from two species of Thalassomyces, phylogenetic analyses robustly place these ellobiopsid species among the alveolates (ciliates, apicomplexans, dinoflagellates and relatives) though without a clear affiliation to any established alveolate lineage. Our trees demonstrate that Thalassomyces fall within a dinoflagellate + apicomplexa + Perkinsidae + "marine alveolate group 1" clade, clustering most closely with dinoflagellates. However, the poor statistical support for branches within this region indicates that additional data will be needed to resolve relationships among these taxa.
艾氏虫是水生甲壳类动物的多核原生生物寄生虫，在宿主体内有一个吸收营养的“根”，以及穿透甲壳的生殖结构。艾氏虫曾被分别归类于真菌、“无色藻类”和甲藻，尽管尚未发现能将它们明确归属于任何特定真核生物谱系的形态特征。很少被观察到的双鞭毛“游动孢子”的拖尾鞭毛和周向鞭毛的排列让人联想到甲藻的鞭毛排列，但从未观察到有组织良好的“甲藻核”。利用来自两种海生艾氏虫的小亚基核糖体RNA基因序列进行系统发育分析，有力地将这些艾氏虫物种置于囊泡虫类（纤毛虫、顶复门、甲藻及相关类群）之中，不过与任何已确定的囊泡虫谱系并无明确关联。我们的系统树表明，海生艾氏虫属于甲藻 + 顶复门 + 派金虫科 + “海洋囊泡虫类群1”的分支，与甲藻的亲缘关系最为密切。然而，该区域内分支的统计支持度较差，这表明需要更多数据来解析这些分类单元之间的关系。
