title: A two-locus molecular characterization of Paramecium calkinsi.
abstract: Paramecium calkinsi (Ciliophora, Protozoa) is a euryhaline species which was first identified in freshwater habitats, but subsequently several strains were also collected from brackish water. It is characterized by clockwise spiral swimming movement and the general morphology of the "bursaria type." The present paper is the first molecular characterization of P. calkinsi strains recently collected in distant regions in Russia using ITS1-5.8S- ITS2-5'LSU rDNA (1100bp) and COI (620bp) mtDNA sequenced gene fragments. For comparison, our molecular analysis includes P. bursaria, exhibiting a similar "bursaria morphotype" as well as species representing the "aurelia type," i.e., P. caudatum, P. multimicronucleatum, P. jenningsi, and P. schewiakoffi, and some species of the P. aurelia species complex (P. primaurelia, P. tetraurelia, P. sexaurelia, and P. tredecaurelia). We also use data from GenBank concerning other species in the genus Paramecium and Tetrahymena (which used as an outgroup). The division of the genus Paramecium into four subgenera (proposed by Fokin et al. 2004) is clearly presented by the trees. There is a clear separation between P. calkinsi strains collected from different regions (races). Consequently, given the molecular distances between them, it seems that these races may represent different syngens within the species.
authors.affiliation: Department of Experimental Zoology, Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Kraków 31-016, Sławkowska 17, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Przyboś
authors.forename: Sebastian
authors.initials: S
authors.lastname: Tarcz
authors.forename: Alexey
authors.initials: A
authors.lastname: Potekhin
authors.forename: Maria
authors.initials: M
authors.lastname: Rautian
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Prajer
mesh_terms: D002467:Cell Nucleus / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D016054:DNA, Protozoan / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D017753:Ecosystem; D014644:Genetic Variation; D018503:Genome, Protozoan; D009711:Nucleotides / Q000235:genetics; D010247:Paramecium / Q000145:classification* / Q000166:cytology / Q000235:genetics*; D010802:Phylogeny; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D012426:Russia; D013045:Species Specificity; D013768:Tetrahymena / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial; D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D009711:Nucleotides; D012340:RNA, Ribosomal, 5.8S