title: Discrepancy between species borders at morphological and molecular levels in the genus Cochliopodium (Amoebozoa, Himatismenida), with the description of Cochliopodium plurinucleolum n. sp.
abstract: Amoebae of the genus Cochliopodium are characterized by a tectum that is a layer of scales covering the dorsal surface of the cell. A combination of scale structure, morphological features and, nowadays, molecular information allows species discrimination. Here we describe a soil species Cochliopodium plurinucleolum n. sp. that besides strong genetic divergence from all currently described species of Cochliopodium differs morphologically by the presence of several peripheral nucleoli in the nucleus. Further, we unambiguously show that the Golgi attachment associated with a dictyosome in Cochliopodium is a cytoplasmic microtubule organizing center (MTOC). Last, we provide detailed morphological and molecular information on the sister clade of C. plurinucleolum, containing C. minus, C. minutoidum, C. pentatrifurcatum and C. megatetrastylus. These species share nearly identical sequences of both, small subunit ribosomal RNA and partial Cox1 genes, and nearly identical structure of the scales. Scales of C. pentatrifurcatum differ, however, strongly from scales of the others while sequences of C. pentatrifurcatum and C. minus are nearly identical. These discrepancies urge for future sampling efforts to disentangle species characteristics within Cochliopdium and to investigate morphological and molecular patterns that allow reliable species differentiation.
authors.affiliation: Department of Terrestrial Ecology, Zoological Institute, Cologne Biocenter, Zülpicher Str. 47b, University of Cologne, 50674 Cologne Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Geisen
authors.affiliation: Department of Invertebrate Zoology, Faculty of Biology and Soil Sciences, St. Petersburg State University, Universitetskaja nab. 7/9 199034 Saint-Petersburg, Russia.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kudryavtsev
authors.affiliation: Department of Terrestrial Ecology, Zoological Institute, Cologne Biocenter, Zülpicher Str. 47b, University of Cologne, 50674 Cologne Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Bonkowski
authors.affiliation: Department of Invertebrate Zoology, Faculty of Biology and Soil Sciences, St. Petersburg State University, Universitetskaja nab. 7/9 199034 Saint-Petersburg, Russia.
authors.forename: Alexey
authors.initials: A
authors.lastname: Smirnov
mesh_terms: D056894:Amoebozoa / Q000145:classification* / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D001483:Base Sequence; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D022101:Microtubule-Organizing Center / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D015800:Protozoan Proteins
keywords: Amoebozoa; Cochliopodium; MTOC; phylogeny; scales; ultrastructure.