title: Evolution of the order Urostylida (Protozoa, Ciliophora): new hypotheses based on multi-gene information and identification of localized incongruence.
abstract: Previous systematic arrangement on the ciliate order Urostylida was mainly based on morphological data and only about 20% taxa were analyzed using molecular phylogenetic analyses. In the present investigation, 22 newly sequenced species for which alpha-tubulin, SSU rRNA genes or ITS1-5.8S-ITS2 region were sampled, refer to all families within the order. Following conclusions could be drawn: (1) the order Urostylida is not monophyletic, but a core group is always present; (2) among the family Urostylidae, six of 10 sequenced genera are rejected belonging to this family; (3) the genus Epiclintes is confirmed belonging to its own taxon; (4) the family Pseudokeronopsidae undoubtedly belongs to the core portion of urostylids; however, some or most of its members should be transferred to the family Urostylidae; (5) Bergeriellidae is confirmed to be a valid family; (6) the distinction of the taxon Acaudalia is not supported; (7) the morphology-based genus Anteholosticha is extremely polyphyletic; (8) ITS2 secondary structures of Pseudoamphisiella and Psammomitra are rather different from other urostylids; (9) partition addition bootstrap alteration (PABA) result shows that bootstrap values usually tend to increase as more gene partitions are included.
authors.affiliation: Laboratory of Protozoology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China.
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Yi
authors.forename: Weibo
authors.initials: W
authors.lastname: Song
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D016798:Ciliophora / Q000235:genetics*; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D030561:Databases, Nucleic Acid; D005796:Genes / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D016053:RNA, Protozoan / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D054679:Ribosome Subunits, Small / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D021903:DNA, Ribosomal Spacer; D016053:RNA, Protozoan; D012335:RNA, Ribosomal