title: Expansion of the 'Reticulosphere': Diversity of Novel Branching and Network-forming Amoebae Helps to Define Variosea (Amoebozoa).
abstract: Amoebae able to form cytoplasmic networks or displaying a multiply branching morphology remain very poorly studied. We sequenced the small-subunit ribosomal RNA gene of 15 new amoeboid isolates, 14 of which are branching or network-forming amoebae (BNFA). Phylogenetic analyses showed that these isolates all group within the poorly-known and weakly-defined class Variosea (Amoebozoa). They are resolved into six lineages corresponding to distinct new morphotypes; we describe them as new genera Angulamoeba (type species Angulamoeba microcystivorans n. gen., n. sp.; and A. fungorum n. sp.), Arboramoeba (type species Arboramoeba reticulata n. gen., n. sp.), Darbyshirella (type species Darbyshirella terrestris n. gen., n. sp.), Dictyamoeba (type species Dictyamoeba vorax n. gen., n. sp.), Heliamoeba (type species Heliamoeba mirabilis n. gen., n. sp.), and Ischnamoeba (type species Ischnamoeba montana n. gen., n. sp.). We also isolated and sequenced four additional variosean strains, one belonging to Flamella, one related to Telaepolella tubasferens, and two members of the cavosteliid protosteloid lineage. We identified a further 104 putative variosean environmental clone sequences in GenBank, comprising up to 14 lineages that may prove to represent additional novel morphotypes. We show that BNFA are phylogenetically widespread in Variosea and morphologically very variable, both within and between lineages.
authors.affiliation: Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom. Electronic address: cedric.berney@sb-roscoff.fr.
authors.forename: Cédric
authors.initials: C
authors.lastname: Berney
authors.affiliation: Department of Terrestrial Ecology, Zoological Institute, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Geisen
authors.affiliation: Research Unit Protistology and Aquatic Ecology, Biology Department, Ghent University, Krijgslaan 281 (S8), 9000 Gent, Belgium.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Van Wichelen
authors.affiliation: Department of General Ecology, Zoological Institute, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Nitsche
authors.affiliation: Research Unit Protistology and Aquatic Ecology, Biology Department, Ghent University, Krijgslaan 281 (S8), 9000 Gent, Belgium.
authors.forename: Pieter
authors.initials: P
authors.lastname: Vanormelingen
authors.affiliation: Department of Terrestrial Ecology, Zoological Institute, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Bonkowski
authors.affiliation: Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Bass
mesh_terms: D000656:Amoeba / Q000145:classification* / Q000166:cytology / Q000235:genetics; D056894:Amoebozoa / Q000145:classification* / Q000166:cytology / Q000235:genetics; D044822:Biodiversity; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D013045:Species Specificity
chemical_list: D012337:RNA, Ribosomal, 18S
keywords: Amoebozoa; Network-forming amoebae; SSU rDNA.; Variosea; molecuar phylogeny; reticulate