title: Diversity, evolution and molecular systematics of the Psalteriomonadidae, the main lineage of anaerobic/microaerophilic heteroloboseans (excavata: discoba).
abstract: We isolated and cultivated 31 strains of free-living heterolobosean flagellates and amoebae from freshwater, brackish, and marine sediments with low concentrations of oxygen. Phylogenetic analysis of small subunit (SSU) rDNA showed that the strains constitute a single clade, the Psalteriomonadidae. According to combined light-microscopic morphology plus molecular phylogeny, our isolates belong to seven species and five genera, from which three species and two genera are new. In addition, previously described anaerobic species Percolomonas descissus and Vahlkampfia anaerobica are transferred to the Psalteriomonadidae. We identified a flagellate stage of Monopylocystis visvesvarai which was reported to produce only amoebae. Two environmental sequences previously obtained from acidic environments belong to the Psalteriomonadidae as well, suggesting a broad ecological importance of the Psalteriomonadidae. The ultrastructure of two psalteriomonadid species was also studied. Unifying features of the Psalteriomonadidae are acristate mitochondrial derivates, flagellates with a ventral groove and four flagella, and a harp-like structure in the mastigont. A new overall classification of the Psalteriomonadidae is proposed. Our data show that the Psalteriomonadidae are much more diverse than previously thought and constitute the main anaerobic lineage within the Heterolobosea.
authors.affiliation: Charles University in Prague, Faculty of Science, Department of Zoology, Vinicna 7, 128 44 Prague, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Pánek
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Silberman
authors.forename: Naoji
authors.initials: N
authors.lastname: Yubuki
authors.forename: Brian S
authors.initials: BS
authors.lastname: Leander
authors.forename: Ivan
authors.initials: I
authors.lastname: Cepicka
mesh_terms: D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D056890:Eukaryota / Q000145:classification* / Q000166:cytology / Q000235:genetics; D020459:Genes, rRNA; D008853:Microscopy; D008969:Molecular Sequence Data; D010802:Phylogeny; D016053:RNA, Protozoan / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA; D014871:Water Microbiology
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D016053:RNA, Protozoan; D012337:RNA, Ribosomal, 18S