title: Toxopsis calypsus gen. nov., sp. nov. (Cyanobacteria, Nostocales) from cave 'Francthi', Peloponnese, Greece: a morphological and molecular evaluation.
abstract: Representatives of a new cyanobacterial genus, Toxopsis Lamprinou & Pantazidou gen. nov., were found in fresh material from Cave 'Francthi' (Peloponnese, Greece) and isolated in cultures. Ecological data relating to the environmental parameters of the sampling sites are provided, such as the photosynthetically active radiation (PAR), temperature and relative humidity. Morphological characteristics and the life cycle of the type species Toxopsis calypsus Lamprinou & Pantazidou sp. nov. were studied using light microscopy and scanning and transmission microscopy. Molecular analysis based on the 16S rRNA gene sequence was also conducted. Toxopsis calypsus sp. nov. is a false-branched nostocalean cyanobacterium with both isopolar and heteropolar filaments bearing mono-pored and bi-pored heterocysts, and also hormogonia and akinetes. Isopolar filaments adhere by the centre to the substrate and are found mainly in fresh material and in young cultures; heteropolar filaments bearing a basic mono-pore heterocyst are dominant in aged (more than one-year-old) cultures. According to the revised taxonomic classification system of Komárek & Anagnostidis (1989) [Komárek, J. & Anagnostidis, K. (1989). Algol Stud, 56, 247-345] based mainly on morphological data, the new genus described here shares morphological characters with both nostocalean families Scytonemataceae and Microchaetaceae, showing similarities in particular to Scytonematopsis contorta [Vaccarino, M. A. & Johansen, J. R. (2011). Fottea 11, 149-161], Microchaetaceae. Molecular data from the 16S rRNA sequence determined in this paper showed that Toxopsis calypsus sp. nov. is more related to the family Microchaetaceae, and the five phylotypes analysed by PCR showed that the closest nostocalean relatives are Tolypothrix distorta SAG 93.79 (GenBank accession no. GQ287651) and Coleodesmium sp. ANT.L52B.5 (AY493596) with 95-96% and 96% similarity, respectively. In contrast, the five phylotypes showed a distant similarity to Scytonematopsis contorta (<91%). The phenotypic and genetic traits strongly supported the classification of the five phylotypes as a new taxon for which the name Toxopsis calypsus Lamprinou & Pantazidou gen. nov., sp. nov. is proposed.
authors.affiliation: University of Athens, Faculty of Biology, Department of Ecology and Systematics, Panepistimiopolis, 15784 Athens, Greece.
authors.forename: V
authors.initials: V
authors.lastname: Lamprinou
authors.affiliation: Hellenic Centre for Marine Research, Institute of Marine Biology and Genetics, Gournes Pediados, PO Box 2214, 71003 Iraklio, Crete, Greece.
authors.forename: K
authors.initials: K
authors.lastname: Skaraki
authors.affiliation: Hellenic Centre for Marine Research, Institute of Marine Biology and Genetics, Gournes Pediados, PO Box 2214, 71003 Iraklio, Crete, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Kotoulas
authors.affiliation: University of Athens, Faculty of Biology, Department of Ecology and Systematics, Panepistimiopolis, 15784 Athens, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Economou-Amilli
authors.affiliation: University of Athens, Faculty of Biology, Department of Ecology and Systematics, Panepistimiopolis, 15784 Athens, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Pantazidou
mesh_terms: D059552:Caves / Q000382:microbiology*; D000458:Cyanobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000648:ultrastructure; D004269:DNA, Bacterial / Q000235:genetics; D006115:Greece; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S