Tsiamis Georgios

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Tsiamis
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Georgios
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  • Article
    New criteria for selecting the origin of DNA replication in Wolbachia and closely related bacteria
    (BioMed Central, 2007-06-20) Ioannidis, Panagiotis ; Dunning Hotopp, Julie C. ; Sapountzis, Panagiotis ; Siozios, Stefanos ; Tsiamis, Georgios ; Bordenstein, Seth R. ; Baldo, Laura ; Werren, John H. ; Bourtzis, Kostas
    Background: The annotated genomes of two closely related strains of the intracellular bacterium Wolbachia pipientis have been reported without the identifications of the putative origin of replication (ori). Identifying the ori of these bacteria and related alpha-Proteobacteria as well as their patterns of sequence evolution will aid studies of cell replication and cell density, as well as the potential genetic manipulation of these widespread intracellular bacteria. Results: Using features that have been previously experimentally verified in the alpha-Proteobacterium Caulobacter crescentus, the origin of DNA replication (ori) regions were identified in silico for Wolbachia strains and eleven other related bacteria belonging to Ehrlichia, Anaplasma, and Rickettsia genera. These features include DnaA-, CtrA- and IHF-binding sites as well as the flanking genes in C. crescentus. The Wolbachia ori boundary genes were found to be hemE and COG1253 protein (CBS domain protein). Comparisons of the putative ori region among related Wolbachia strains showed higher conservation of bases within binding sites. Conclusion: The sequences of the ori regions described here are only similar among closely related bacteria while fundamental characteristics like presence of DnaA and IHF binding sites as well as the boundary genes are more widely conserved. The relative paucity of CtrA binding sites in the ori regions, as well as the absence of key enzymes associated with DNA replication in the respective genomes, suggest that several of these obligate intracellular bacteria may have altered replication mechanisms. Based on these analyses, criteria are set forth for identifying the ori region in genome sequencing projects.
  • Article
    Insights into the phylogeny and coding potential of microbial dark matter
    (Nature Publishing Group, 2013-07-14) Rinke, Christian ; Schwientek, Patrick ; Sczyrba, Alexander ; Ivanova, Natalia N. ; Anderson, Iain J. ; Cheng, Jan-Fang ; Darling, Aaron ; Malfatti, Stephanie A. ; Swan, Brandon K. ; Gies, Esther A. ; Dodsworth, Jeremy A. ; Hedlund, Brian P. ; Tsiamis, Georgios ; Sievert, Stefan M. ; Liu, Wen-Tso ; Eisen, Jonathan A. ; Hallam, Steven J. ; Kyrpides, Nikos C. ; Stepanauskas, Ramunas ; Rubin, Edward M. ; Hugenholtz, Philip ; Woyke, Tanja
    Genome sequencing enhances our understanding of the biological world by providing blueprints for the evolutionary and functional diversity that shapes the biosphere. However, microbial genomes that are currently available are of limited phylogenetic breadth, owing to our historical inability to cultivate most microorganisms in the laboratory. We apply single-cell genomics to target and sequence 201 uncultivated archaeal and bacterial cells from nine diverse habitats belonging to 29 major mostly uncharted branches of the tree of life, so-called ‘microbial dark matter’. With this additional genomic information, we are able to resolve many intra- and inter-phylum-level relationships and to propose two new superphyla. We uncover unexpected metabolic features that extend our understanding of biology and challenge established boundaries between the three domains of life. These include a novel amino acid use for the opal stop codon, an archaeal-type purine synthesis in Bacteria and complete sigma factors in Archaea similar to those in Bacteria. The single-cell genomes also served to phylogenetically anchor up to 20% of metagenomic reads in some habitats, facilitating organism-level interpretation of ecosystem function. This study greatly expands the genomic representation of the tree of life and provides a systematic step towards a better understanding of biological evolution on our planet.
  • Article
    The ocean sampling day consortium
    (BioMed Central, 2015-06-19) Kopf, Anna ; Bicak, Mesude ; Kottmann, Renzo ; Schnetzer, Julia ; Kostadinov, Ivaylo ; Lehmann, Katja ; Fernandez-Guerra, Antonio ; Jeanthon, Christian ; Rahav, Eyal ; Ullrich, Matthias S. ; Wichels, Antje ; Gerdts, Gunnar ; Polymenakou, Paraskevi ; Kotoulas, Georgios ; Siam, Rania ; Abdallah, Rehab Z. ; Sonnenschein, Eva C. ; Cariou, Thierry ; O’Gara, Fergal ; Jackson, Stephen ; Orlic, Sandi ; Steinke, Michael ; Busch, Julia ; Duarte, Bernardo ; Caçador, Isabel ; Canning-Clode, Joao ; Bobrova, Oleksandra ; Marteinsson, Viggo ; Reynisson, Eyjolfur ; Loureiro, Clara Magalhaes ; Luna, Gian Marco ; Quero, Grazia Marina ; Loscher, Carolin R. ; Kremp, Anke ; DeLorenzo, Marie E. ; Øvreås, Lise ; Tolman, Jennifer ; LaRoche, Julie ; Penna, Antonella ; Frischer, Marc ; Davis, Timothy ; Katherine, Barker ; Meyer, Christopher P. ; Ramos, Sandra ; Magalhaes, Catarina ; Jude-Lemeilleur, Florence ; Aguirre-Macedo, Ma Leopoldina ; Wang, Shiao ; Poulton, Nicole ; Jones, Scott ; Collin, Rachel ; Fuhrman, Jed A. ; Conan, Pascal ; Alonso, Cecilia ; Stambler, Noga ; Goodwin, Kelly ; Yakimov, Michail M. ; Baltar, Federico ; Bodrossy, Levente ; Van De Kamp, Jodie ; Frampton, Dion M. F. ; Ostrowski, Martin ; Van Ruth, Paul ; Malthouse, Paul ; Claus, Simon ; Deneudt, Klaas ; Mortelmans, Jonas ; Pitois, Sophie ; Wallom, David ; Salter, Ian ; Costa, Rodrigo ; Schroeder, Declan C. ; Kandil, Mahrous M. ; Amaral, Valentina ; Biancalana, Florencia ; Santana, Rafael ; Pedrotti, Maria Luiza ; Yoshida, Takashi ; Ogata, Hiroyuki ; Ingleton, Timothy ; Munnik, Kate ; Rodriguez-Ezpeleta, Naiara ; Berteaux-Lecellier, Veronique ; Wecker, Patricia ; Cancio, Ibon ; Vaulot, Daniel ; Bienhold, Christina ; Ghazal, Hassan ; Chaouni, Bouchra ; Essayeh, Soumya ; Ettamimi, Sara ; Zaid, El Houcine ; Boukhatem, Noureddine ; Bouali, Abderrahim ; Chahboune, Rajaa ; Barrijal, Said ; Timinouni, Mohammed ; El Otmani, Fatima ; Bennani, Mohamed ; Mea, Marianna ; Todorova, Nadezhda ; Karamfilov, Ventzislav ; ten Hoopen, Petra ; Cochrane, Guy R. ; L’Haridon, Stephane ; Bizsel, Kemal Can ; Vezzi, Alessandro ; Lauro, Federico M. ; Martin, Patrick ; Jensen, Rachelle M. ; Hinks, Jamie ; Gebbels, Susan ; Rosselli, Riccardo ; De Pascale, Fabio ; Schiavon, Riccardo ; dos Santos, Antonina ; Villar, Emilie ; Pesant, Stephane ; Cataletto, Bruno ; Malfatti, Francesca ; Edirisinghe, Ranjith ; Herrera Silveira, Jorge A. ; Barbier, Michele ; Turk, Valentina ; Tinta, Tinkara ; Fuller, Wayne J. ; Salihoglu, Ilkay ; Serakinci, Nedime ; Ergoren, Mahmut Cerkez ; Bresnan, Eileen ; Iriberri, Juan ; Fronth Nyhus, Paul Anders ; Bente, Edvardsen ; Karlsen, Hans Erik ; Golyshin, Peter N. ; Gasol, Josep M. ; Moncheva, Snejana ; Dzhembekova, Nina ; Johnson, Zackary ; Sinigalliano, Christopher D. ; Gidley, Maribeth Louise ; Zingone, Adriana ; Danovaro, Roberto ; Tsiamis, Georgios ; Clark, Melody S. ; Costa, Ana Cristina ; El Bour, Monia ; Martins, Ana M. ; Collins, R. Eric ; Ducluzeau, Anne-Lise ; Martinez, Jonathan ; Costello, Mark J. ; Amaral-Zettler, Linda A. ; Gilbert, Jack A. ; Davies, Neil ; Field, Dawn ; Glockner, Frank Oliver
    Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits.