title: The chaos prevails: molecular phylogeny of the Haptoria (Ciliophora, Litostomatea).
abstract: The Haptoria are free-living predatory ciliates living in terrestrial and aquatic habitats all around the world. They belong to a highly diverse class, Litostomatea, whose morphological and molecular classifications harmonize poorly since both approaches produce rather different frameworks. In the present study, we analyzed the genealogy of the litostomateans, including eight new haptorian 18S rRNA gene sequences. Apart from traditional tree-building methods, we also applied phylogenetic networks, split spectrum analysis and quartet likelihood mapping to assess the information content of alignments. These analyses show that: (1) there are several strongly supported monophyletic litostomatean lineages--Rhynchostomatia, Trichostomatia, Haptorida, Lacrymariida, Pleurostomatida, and Didiniida; (2) the Rhynchostomatia are the best candidates for a basal litostomatean group; (3) sister relationship of the Trichostomatia and Haptoria is very likely, which well corroborates the traditional morphology-based classifications; (4) molecular phylogeny of the order Spathidiida is only poorly resolved very likely due to one or several rapid radiation events or due to the incomplete lineage sorting at the rRNA locus; and (5) the basal position of the genera Chaenea and Trachelotractus in molecular trees and phylogenetic networks is very likely a result of class III long-branch effects.
authors: Department of Zoology, Comenius University, Mlynská dolina B-1, SK-84215 Bratislava, Slovakia. Electronic address: vdacny@fns.uniba.sk.
authors: Peter
authors: P
authors: Vďačný
authors: Department of Ecology, University of Kaiserslautern, Erwin-Schroedinger-Strasse 14, D-67663, Germany.
authors: Hans-Werner
authors: HW
authors: Breiner
authors: Department of Ecology, University of Kaiserslautern, Erwin-Schroedinger-Strasse 14, D-67663, Germany; Department of Organismal Biology, University of Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria.
authors: Varvara
authors: V
authors: Yashchenko
authors: Department of Ecology, University of Kaiserslautern, Erwin-Schroedinger-Strasse 14, D-67663, Germany.
authors: Micah
authors: M
authors: Dunthorn
authors: Department of Ecology, University of Kaiserslautern, Erwin-Schroedinger-Strasse 14, D-67663, Germany.
authors: Thorsten
authors: T
authors: Stoeck
authors: Department of Organismal Biology, University of Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria.
authors: Wilhelm
authors: W
authors: Foissner
mesh_terms: D016798:Ciliophora / Q000145:classification* / Q000235:genetics*; D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D020459:Genes, rRNA; D008969:Molecular Sequence Data; D010802:Phylogeny; D016053:RNA, Protozoan / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D016053:RNA, Protozoan; D012337:RNA, Ribosomal, 18S
keywords: 18S rRNA gene; long-branch species; phylogenetic networks; quartet mapping; radiation; split spectrum.