title: Three-gene based phylogeny of the Urostyloidea (Protista, Ciliophora, Hypotricha), with notes on classification of some core taxa.
abstract: Classifications of the Urostyloidea were mainly based on morphology and morphogenesis. Since molecular phylogeny largely focused on limited sampling using mostly the one-gene information, the incongruence between morphological data and gene sequences have risen. In this work, the three-gene data (SSU-rDNA, ITS1-5.8S-ITS2 and LSU-rDNA) comprising 12 genera in the "core urostyloids" are sequenced, and the phylogenies based on these different markers are compared using maximum-likelihood and Bayesian algorithms and tested by unconstrained and constrained analyses. The molecular phylogeny supports the following conclusions: (1) the monophyly of the core group of Urostyloidea is well supported while the whole Urostyloidea is not monophyletic; (2) Thigmokeronopsis and Apokeronopsis are clearly separated from the pseudokeronopsids in analyses of all three gene markers, supporting their exclusion from the Pseudokeronopsidae and the inclusion in the Urostylidae; (3) Diaxonella and Apobakuella should be assigned to the Urostylidae; (4) Bergeriella, Monocoronella and Neourostylopsis flavicana share a most recent common ancestor; (5) all molecular trees support the transfer of Metaurostylopsis flavicana to the recently proposed genus Neourostylopsis; (6) all molecular phylogenies fail to separate the morphologically well-defined genera Uroleptopsis and Pseudokeronopsis; and (7) Arcuseries gen. nov. containing three distinctly deviating Anteholosticha species is established.
authors.affiliation: Laboratory of Protozoology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Huang
authors.forename: Zigui
authors.initials: Z
authors.lastname: Chen
authors.forename: Weibo
authors.initials: W
authors.lastname: Song
authors.forename: Helmut
authors.initials: H
authors.lastname: Berger
mesh_terms: D001499:Bayes Theorem; D016798:Ciliophora / Q000145:classification / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer
keywords: Ciliophora; Evolution; Phylogeny; Three genes; Urostyloidea