Molecular phylogeny and surface morphology of Colpodella edax (Alveolata):: Insights into the phagotrophic ancestry of apicomplexans
Molecular phylogeny and surface morphology of Colpodella edax (Alveolata):: Insights into the phagotrophic ancestry of apicomplexans
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DOI：
10.1111/j.1550-7408.2003.tb00145.x
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发表时间：
2003-09-01
影响因子：
2.2
通讯作者：
Keeling, PJ
中科院分区：
文献类型：
--
作者：
Leander, BS;Kuvardina, ON;Keeling, PJ
顶复合体的分子系统发育为推测顶复合体进化的最早阶段以及顶复合体和鞭毛纲的最后共同祖先的特征提供了一个框架。我们通过对缺氧环境分子系统发育调查中发表的Colpodella edax和三种未识别真核生物的小亚基rRNA基因序列进行系统发育分析，扩展了这项研究。系统发育分析一致表明，C. edax和环境序列嵌套在一个鞘翅目分支中，形成了（eu）顶复合体的姊妹类群。我们还利用扫描电子显微镜展示了C. edax的表面细节，以补充以前使用透射电子显微镜对该物种的超微结构研究，并为解释环境序列提供形态学背景。显微数据证实了微孔的稀疏分布，为无角形。由小的多角形肺泡、前鞭毛上的鞭毛和由其下的（开放的）圆锥骨形成的喙部组成。在一些个体中存在三个鞭毛，在一些顶复合体的小配子中也发现了一个特殊的特征。
The molecular phylogeny of colpodellids provides a framework for inferences about the earliest stages in apicomplexan evolution and the characteristics of the last common ancestor of apicomplexans and dinoflagellates. We extended this research by presenting phylogenetic analyses of small subunit rRNA gene sequences from Colpodella edax and three unidentified eukaryotes published from molecular phylogenetic surveys of anoxic environments. Phylogenetic analyses consistently showed C. edax and the environmental sequences nested within a colpodellid clade, which formed the sister group to (eu)apicomplexans. We also presented surface details of C. edax using scanning electron microscopy in order to supplement previous ultrastructural investigations of this species using transmission electron microscopy and to provide morphological context for interpreting environmental sequences. The microscopical data confirmed a sparse distribution of micropores, an amphiesma. consisting of small polygonal alveoli, flagellar hairs on the anterior flagellum, and a rostrum molded by the underlying (open-sided) conoid. Three flagella were present in some individuals, a peculiar feature also found in the microgametes of some apicomplexans.