title: Light microscopic observations, ultrastructure, and molecular phylogeny of Hicanonectes teleskopos n. g., n. sp., a deep-branching relative of diplomonads.
abstract: We describe Hicanonectes teleskopos n. g., n. sp., a heterotrophic flagellate isolated from low-oxygen marine sediment. Hicanonectes teleskopos has a ventral groove and two unequal flagella, and rapidly rotates during swimming. At the ultrastructural level H. teleskopos is a "typical excavate": it displays flagellar vanes, a split right microtubular root, "I,""B," and "C" fibres, a singlet microtubular root, and a possible composite fibre. Small subunit rRNA (SSU rRNA) gene phylogenies and an "arched" B fibre demonstrate that H. teleskopos belongs to Fornicata (i.e. diplomonads, retortamonads, and relatives). It forms a clade with the deep-branching fornicate Carpediemonas, with moderate-to-strong bootstrap support, although their SSU rRNA gene sequences are quite dissimilar. Hicanonectes differs from Carpediemonas in cell shape, swimming behaviour, number of basal bodies (i.e. 4 vs. 3), number of flagellar vanes (i.e. 2 vs. 3), anterior root organization, and by having a cytopharynx. Like Carpediemonas and Dysnectes, Hicanonectes has conspicuous mitochondrion-like organelles that lack cristae and superficially resemble the hydrogenosomes of parabasalids, rather than the mitosomes of their closer relatives the diplomonads (e.g. Giardia).
authors: Canadian Institute for Advanced Research, Program in Integrated Microbial Diversity, and Department of Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4J1 Canada.
authors: Jong Soo
authors: JS
authors: Park
authors: Martin
authors: M
authors: Kolisko
authors: Aaron A
authors: AA
authors: Heiss
authors: Alastair G B
authors: AG
authors: Simpson
mesh_terms: D000818:Animals; D016054:DNA, Protozoan / Q000032:analysis / Q000235:genetics; D016828:Diplomonadida / Q000145:classification / Q000235:genetics / Q000648:ultrastructure; D005407:Flagella / Q000648:ultrastructure; D020459:Genes, rRNA; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000648:ultrastructure; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D016054:DNA, Protozoan