Molecular phylogeny of the scuticociliate, Philaster (Protozoa, Ciliophora), with a description of a new species, P. apodigitiformis sp nov.
Molecular phylogeny of the scuticociliate, Philaster (Protozoa, Ciliophora), with a description of a new species, P. apodigitiformis sp nov.
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DOI：
10.1017/s1477200009990193
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发表时间：
2009-12-01
影响因子：
1.9
通讯作者：
Song, Weibo
中科院分区：
文献类型：
--
作者：
Miao, Miao;Wang, Yangang;Song, Weibo
由于缺乏形态发生或分子信息，盾纤毛虫 Philaster 的系统地位一直非常模糊。新物种 Philaster apodigitiformis sp. 的小亚基 rRNA 基因。十一月从河豚鱼（Takifugu rubripes）的卵中分离出来，进行测序，并用不同的方法构建系统发育树，以评估其在盾纤毛虫中的位置和关系。结果表明：(1) Philaster apodigitiformis 显然属于 Philasterida 目，并且与 Uronema-Paranophrys 组合关系最密切，该组合由 Uronematidae 科、Parauronematidae 科、Thyrophilacidae 科和 Entorhipidiidae 科组成。 (2) 目前归入 Philasteridae 科的 Philaster 和 Philasterides 两个属处于相距甚远的进化支中，表明该科是多系的； (3) Philaster 和 Philasterides 的形态相似性可能是进化趋同的一个例子。新种 P. apodigitiformis 的识别具有以下特征的组合：体呈椭圆形且两侧略扁，口膜纤毛明显长且形成帆状，膜 1 和膜 2 均占主导地位，存在约 40 个体细胞运动。
The systematic position of the scuticociliate, Philaster, has been highly ambiguous owing to a lack of either morphogenetic or molecular information. The small subunit rRNA gene of a new species, Philaster apodigitiformis sp. nov. was isolated from eggs of the puffer fish (Takifugu rubripes), was sequenced, and phylogenetic trees were constructed with different methods to assess its position and relationship among the scuticociliates. Results indicate that (1) Philaster apodigitiformis clearly falls into the order Philasterida and it is most closely related to the Uronema-Paranophrys assemblage, which groups with clusters consisting of families Uronematidae, Parauronematidae, Thyrophilacidae and Entorhipidiidae; (2) the two genera Philaster and Philasterides presently assigned to the family Philasteridae are in widely separated clades, indicating that the family is polyphyletic; and (3) the morphological similarity of Philaster and Philasterides is probably an example of evolutionary convergence. The new species P. apodigitiformis is recognised by a combination of the following features: body oval and slightly bilaterally flattened, cilia of paroral membrane conspicuously long and forming a sail-like shape, both membranelle 1 and 2 dominant, and approximately 40 somatic kineties present.