Evolutionary genomics of the cold-adapted diatom Fragilariopsis cylindrus.

• Published in: Nature
• Main Authors: Mock, Thomas, Otillar, Robert P, Strauss, Jan, McMullan, Mark, Paajanen, Pirita, Schmutz, Jeremy, Salamov, Asaf, Sanges, Remo, Toseland, Andrew, Ward, Ben J, Allen, Andrew E, Dupont, Chris, Frickenhaus, Stephan, Maumus, Florian, Veluchamy, Alaguraj, Wu, Taoyang, Barry, Kerrie W, Falciatore, Angela, Ferrante, Maria I, Fortunato, Antonio E, Glöckner, Gernot, Gruber, Ansgar, Hipkin, Rachel, Janech, Michael G, Kroth, Peter G, Leese, Florian, Lindquist, Erika A, Lyon, Barbara R, Martin, Joel, Mayer, Chris, Parker, Micaela, Quesneville, Hadi, Raymond, James A, Uhlig, Chris, Valas, Ruben E, Valentin, Klaus U, Worden, Alexandra Z, Armbrust, E Virginia, Clark, Matthew D, Bowler, Chris, Green, Beverley R, Moulton, Vincent, van Oosterhout, Cock, Grigoriev, Igor V
• Other Authors: School of Environmental Sciences Norwich, University of East Anglia Norwich (UEA), Joint Genome Institute, United States Department of Energy, Hudson Alpha Institute, Sezione Ecologia Marina Integrata, Stazione Zoologica Anton Dohrn (SZN), School of Physics NUI Galway, National University of Ireland Galway (NUI Galway), Infection et inflammation (2I), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Unité de Recherche Génomique Info (URGI), Institut National de la Recherche Agronomique (INRA), Technical University of Munich (TUM), Biologie Computationnelle et Quantitative = Laboratory of Computational and Quantitative Biology (LCQB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Genomics Institute for Biochemistry I, University of Cologne, University of Innsbruck, Laboratoire Genome Population & Interactions, Université Montpellier 2 - Sciences et Techniques (UM2)-ORSTOM-Centre National de la Recherche Scientifique (CNRS), Department of Biology, University of Konstanz, Animal Ecology, Evolution and Biodiversity, Ruhr-Universität Bochum Bochum, Univ Reading, Sch Chem Pharm & Food Biosci, Reading RG6 6AD, Berks, England, Canadian Institute for Advanced Research (CIFAR), Monterey Bay Aquarium Research Institute (MBARI), Monterey Bay Aquarium Research Institute, University of California Santa Cruz (UCSC), University of California, School of Oceanography Seattle, University of Washington Seattle, Johns Hopkins University School of Medicine Baltimore, Department of Computer Science, DOE Joint Genome Institute Walnut Creek, ERC Advanced Grant ERC-2011-ADG (Diatomite) - Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 - NERC under grants NE/I001751/1, NE/K004530/1, MGF (NBAF) grant 197, The Royal Society grant RG090774 and the Earth & Life Systems Alliance in Norwich, European Project: 294823,EC:FP7:ERC,ERC-2011-ADG_20110310,DIATOMITE(2012)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: [SDV]Life Sciences [q-bio]; Southern Ocean; Strauss; Sea ice
• Online Access: https://hal.sorbonne-universite.fr/hal-01587937; https://doi.org/10.1038/nature20803

Robert P. Otillar - Jan Strauss : co-second auteur International audience The Southern Ocean houses a diverse and productive community of organisms. Unicellular eukaryotic diatoms are the main primary producers in this environment, where photosynthesis is limited by low concentrations of dissolved iron and large seasonal fluctuations in light, temperature and the extent of sea ice. How diatoms have adapted to this extreme environment is largely unknown. Here we present insights into the genome evolution of a cold-adapted diatom from the Southern Ocean, Fragilariopsis cylindrus, based on a comparison with temperate diatoms. We find that approximately 24.7 per cent of the diploid F. cylindrus genome consists of genetic loci with alleles that are highly divergent (15.1 megabases of the total genome size of 61.1 megabases). These divergent alleles were differentially expressed across environmental conditions, including darkness, low iron, freezing, elevated temperature and increased CO2. Alleles with the largest ratio of non-synonymous to synonymous nucleotide substitutions also show the most pronounced condition-dependent expression, suggesting a correlation between diversifying selection and allelic differentiation. Divergent alleles may be involved in adaptation to environmental fluctuations in the Southern Ocean.