title: Phylogenetic relationships within the class Spirotrichea (Ciliophora) inferred from small subunit rRNA gene sequences.
abstract: The small subunit rDNAs of five species belonging to the Euplotidae and eight species of the Oxytrichidae were sequenced to obtain a more detailed picture of the phylogenetic relationships within the Spirotrichea (Ciliophora). Various tree reconstruction algorhythms yielded nearly identical topologies. All Euplotidae were separated from the other Spirotrichea by a deep split. Further, a large genetic distance between the marine genus Moneuplotes and the freshwater species of Euplotoides was found. Differences between the methods used occurred only within the Oxytrichidae. Whereas the monophyly of the Stylonychinae was supported in all trees, the monophyly of the Oxytrichinae was not. However, the molecular data support the morphological and ontogenetic evidence that the pattern of 18 frontal-ventral-transversal cirri evolved in the stemline of the Oxytrichidae and was modified several times independently. Our results are also in agreement with taxonomic revisions: the separation of both Sterkiella nova from Oxytricha and Tetmemena pustulata from Stylonychia.
authors.affiliation: Spezielle Zoologie, Institut für Zoologie, Universität Leipzig, Talstrasse 33, D-04103 Leipzig, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Bernhard
authors.forename: A
authors.initials: A
authors.lastname: Stechmann
authors.forename: W
authors.initials: W
authors.lastname: Foissner
authors.forename: D
authors.initials: D
authors.lastname: Ammermann
authors.forename: M
authors.initials: M
authors.lastname: Hehn
authors.forename: M
authors.initials: M
authors.lastname: Schlegel
mesh_terms: D000818:Animals; D001483:Base Sequence; D016798:Ciliophora / Q000145:classification / Q000235:genetics*; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D016054:DNA, Protozoan; D012337:RNA, Ribosomal, 18S