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BACKGROUND The Euglenozoa is a large group of eukaryotic flagellates with diverse modes of nutrition. The group consists of three main subclades - euglenids, kinetoplastids and diplonemids--that have been confirmed with both molecular phylogenetic analyses and a combination of shared ultrastructural characteristics. Several poorly understood lineages of(More)
BACKGROUND Poorly understood but highly diverse microbial communities exist within anoxic and oxygen-depleted marine sediments. These communities often harbour single-celled eukaryotes that form symbiotic associations with different prokaryotes. During low tides in South-western British Columbia, Canada, vast areas of marine sand become exposed, forming(More)
Morphostasis of traits in different species is necessary for reconstructing the evolutionary history of complex characters. Studies that place these species into a molecular phylogenetic context test hypotheses about the transitional stages that link divergent character states. For instance, the transition from a phagotrophic mode of nutrition to a(More)
Over the last 15 years classical culturing and environmental PCR techniques have revealed a modest number of genuinely new major lineages of protists; however, some new groups have greatly influenced our understanding of eukaryote evolution. We used culturing techniques to examine the diversity of free-living protists that are relatives of diplomonads and(More)
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(More)
Three heterotrophic stramenopiles--Apoikia lindahlii comb. nov. (Chrysophyceae), Filos agilis gen. et sp. nov. (Bicosoecida), and Nanos amicus gen. et sp. nov. (Bicosoecida)--were isolated from acidic peat bogs. The biflagellate A. lindahlii forms loose irregular colonies from which swimming cells may detach, and produces extensive mucilaginous material(More)
Athecate, pseudocolony-forming dinoflagellates have been classified within two genera of polykrikoids, Polykrikos and Pheopolykrikos, and different views about the boundaries and composition of these genera have been expressed in the literature. The photosynthetic polykrikoid Pheopolykrikos hartmannii, for instance, was originally described within(More)
Although Stephanopogon was described as a putative ciliate more than a century ago, its phylogenetic position within eukaryotes has remained unclear because of an unusual combination of morphological characteristics (e.g. a highly multiflagellated cell with discoidal mitochondrial cristae). Attempts to classify Stephanopogon have included placement with the(More)
Ultrastructural and molecular phylogenetic evidence indicate that the Parabasalia consists of seven main subgroups: the Trichomonadida, Honigbergiellida, Hypotrichomonadida, Tritrichomonadida, Cristamonadida, Spirotrichonymphida, and Trichonymphida. Only five species of free-living parabasalids are known: Monotrichomonas carabina, Ditrichomonas honigbergii,(More)
The architecture of eukaryotic cells is underpinned by complex arrrays of microtubules that stem from an organizing center, referred to as the MTOC. With few exceptions, MTOCs consist of two basal bodies that anchor flagellar axonemes and different configurations of microtubular roots. Variations in the structure of this cytoskeletal system, also referred(More)