title: Multi-gene-based phylogenetic analysis of oligotrich ciliates with emphasis on two dominant groups: Cyrtostrombidiids and strombidiids (Protozoa, Ciliophora).
abstract: Phylogenetic analyses of ciliated protists are frequently based on single molecular markers, usually the small subunit ribosomal RNA gene (SSU rDNA), despite the well-known limitations of this approach. Here, 78 new sequences of three linked genes (SSU rDNA, ITS1-5.8S rDNA-ITS2, LSU rDNA) were characterized and applied to phylogenetic analyses of oligotrichs (s. str.). It was found that: (1) three taxa, that is tontoniids, pelagostrombidiids and cyrtostrombidiids should be split from the family Strombidiidae (s. l.), which supports Agatha's classification based on morphological characters; (2) the families Tontoniidae and Cyrtostrombidiidae are both monophyletic whereas Strombidiidae is polyphyletic; (3) the positions of the families Cyrtostrombidiidae and Pelagostrombidiidae varied in different trees although with low support values; (4) the close relationship between Varistrombidium and Apostrombidium is confirmed, which updates the evolutionary hypothesis for oligotrichs based on ciliary patterns; and (5) two relatively stable clades were found in the family Strombidiidae.
authors: Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.
authors: Feng
authors: F
authors: Gao
authors: Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.
authors: Jiamei
authors: J
authors: Li
authors: Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.
authors: Wen
authors: W
authors: Song
authors: State Key Laboratory of Marine Environmental Science (MEL), & Institute of Marine Microbes and Ecospheres (IME), Xiamen University, Xiamen 361102, China.
authors: Dapeng
authors: D
authors: Xu
authors: Department of Life Sciences, Natural History Museum, London SW7 5BD, UK.
authors: Alan
authors: A
authors: Warren
authors: Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China. Electronic address: zyi@scnu.edu.cn.
authors: Zhenzhen
authors: Z
authors: Yi
authors: Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China. Electronic address: shangao@ouc.edu.cn.
authors: Shan
authors: S
authors: Gao
mesh_terms: D005075:Biological Evolution; D016798:Ciliophora / Q000145:classification* / Q000235:genetics; D016054:DNA, Protozoan; D004275:DNA, Ribosomal / Q000235:genetics; D020459:Genes, rRNA; D058889:Molecular Typing; D010802:Phylogeny; D054679:Ribosome Subunits, Small; D017422:Sequence Analysis, DNA
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal
keywords: Cyrtostrombidiidae; Oligotrichia; Pelagostrombidiidae; phylogeny; rDNA