title: Molecular phylogenetics of subclass Peritrichia (Ciliophora: Oligohymenophorea) based on expanded analyses of 18S rRNA sequences.
abstract: Phylogenetic relationships among peritrich ciliates remain unclear in spite of recent progress. To expand the analyses performed in previous studies, and to statistically test hypotheses of monophyly, we analyzed a broad sample of 18s rRNA sequences (including 15 peritrich genera), applying a conservative alignment strategy and several phylogenetic approaches. The main results are that: (i) the monophyly of Peritrichia cannot be rejected; (ii) the two main clades of Sessilida do not correspond to formally recognized taxa; (iii) the monophyly of genera Vorticella and Epistylis is significantly rejected; and (iv) morphological structures commonly used in peritrich taxonomy may be evolutionarily labile.
authors.affiliation: Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS, Brazil. laurautz@yahoo.com
authors.forename: Laura R P
authors.initials: LR
authors.lastname: Utz
authors.forename: Eduardo
authors.initials: E
authors.lastname: Eizirik
mesh_terms: D000818:Animals; D016802:Oligohymenophorea / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D016053:RNA, Protozoan / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics
chemical_list: D016053:RNA, Protozoan; D012337:RNA, Ribosomal, 18S