The Genome of the Diatom Thalassiosira Pseudonana: Ecology, Evolution, and Metabolism

E. Virginia Armbrust, John A. Berges, Chris Bowler, Beverley R. Green, Diego Martinez, Nicholas H. Putnam, Shiguo Zhou, Andrew E. Allen, Kirk E. Apt, Michael Bechner, Mark A. Brzezinski, Balbir K. Chaal, Anthony Chiovitti, Aubrey K. Davis, Mark S. Demarest, J. Chris Detter, Tijana Glavina, David Goodstein, Masood Z. Hadi, Uffe Hellsten, Mark Hildebrand, Bethany D. Jenkins, Jerzy Jurka, Vladimir V. Kapitonov, Nils Kröger, Winnie W. Y. Lau, Todd W. Lane, Frank W. Larimer, J. Casey Lippmeier, Susan Lucas, Mónica Medina, Anton Montsant, Miroslav Obornik, Micaela Schnitzler Parker, Brian Palenik, Gregory J. Pazour, Paul M. Richardson, Tatiana A. Rynearson, Mak A. Saito, David C. Schwartz, Kimberlee Thamatrakoln, Klaus Valentin, Assaf Vardi, Frances P. Wilkerson, and Daniel S. Rokhsar

Science 1 October 2004: 79-86. Diatoms, key members of marine and freshwater ecosystems, have genes for the urea cycle, for using lipids as an energy source, and for synthesizing their ornate, silica-based cell walls. Abstract »|          Full Text »|                    PDF »|                    Supporting Online Material »|

Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for 20% of global carbon fixation. We report the 34 million–base pair draft nuclear genome of the marine diatom Thalassiosira pseudonana and its 129 thousand–base pair plastid and 44 thousand–base pair mitochondrial genomes. Sequence and optical restriction mapping revealed 24 diploid nuclear chromosomes. We identified novel genes for silicic acid transport and formation of silica-based cell walls, high-affinity iron uptake, biosynthetic enzymes for several types of polyunsaturated fatty acids, use of a range of nitrogenous compounds, and a complete urea cycle, all attributes that allow diatoms to prosper in aquatic environments.