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Author

Anton Montsant

Other affiliations: Stazione Zoologica Anton Dohrn
Bio: Anton Montsant is an academic researcher from École Normale Supérieure. The author has contributed to research in topics: Phaeodactylum tricornutum & Thalassiosira pseudonana. The author has an hindex of 9, co-authored 9 publications receiving 3885 citations. Previous affiliations of Anton Montsant include Stazione Zoologica Anton Dohrn.

Papers
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Journal ArticleDOI
01 Oct 2004-Science
TL;DR: 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 were reported in this article.
Abstract: Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for approximately 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.

1,945 citations

Journal ArticleDOI
13 Nov 2008-Nature
TL;DR: Analysis of molecular divergence compared with yeasts and metazoans reveals rapid rates of gene diversification in diatoms, and documents the presence of hundreds of genes from bacteria, likely to provide novel possibilities for metabolite management and for perception of environmental signals.
Abstract: Diatoms are photosynthetic secondary endosymbionts found throughout marine and freshwater environments, and are believed to be responsible for around one- fifth of the primary productivity on Earth(1,2). The genome sequence of the marine centric diatom Thalassiosira pseudonana was recently reported, revealing a wealth of information about diatom biology(3-5). Here we report the complete genome sequence of the pennate diatom Phaeodactylum tricornutum and compare it with that of T. pseudonana to clarify evolutionary origins, functional significance and ubiquity of these features throughout diatoms. In spite of the fact that the pennate and centric lineages have only been diverging for 90 million years, their genome structures are dramatically different and a substantial fraction of genes (similar to 40%) are not shared by these representatives of the two lineages. Analysis of molecular divergence compared with yeasts and metazoans reveals rapid rates of gene diversification in diatoms. Contributing factors include selective gene family expansions, differential losses and gains of genes and introns, and differential mobilization of transposable elements. Most significantly, we document the presence of hundreds of genes from bacteria. More than 300 of these gene transfers are found in both diatoms, attesting to their ancient origins, and many are likely to provide novel possibilities for metabolite management and for perception of environmental signals. These findings go a long way towards explaining the incredible diversity and success of the diatoms in contemporary oceans.

1,500 citations

Journal ArticleDOI
30 Dec 2007-Gene
TL;DR: The identification of several reference genes that can be used as internal standards for gene expression studies by quantitative real-time PCR (qRT-PCR) in P. tricornutum cells grown over a diel cycle are reported.

324 citations

Journal ArticleDOI
TL;DR: A number of intriguing differences were identified between the pennate and the centric diatoms concerning activities of relevance for general cell metabolism, e.g. genes involved in carbon-concentrating mechanisms, cytosolic acetyl-Coenzyme A production, and fructose-1,6-bisphosphate metabolism.
Abstract: Diatoms are one of the most important constituents of phytoplankton communities in aquatic environments, but in spite of this, only recently have large-scale diatom-sequencing projects been undertaken. With the genome of the centric species Thalassiosira pseudonana available since mid-2004, accumulating sequence information for a pennate model species appears a natural subsequent aim. We have generated over 12,000 expressed sequence tags (ESTs) from the pennate diatom Phaeodactylum tricornutum, and upon assembly into a nonredundant set, 5,108 sequences were obtained. Significant similarity (E < 1E-04) to entries in the GenBank nonredundant protein database, the COG profile database, and the Pfam protein domains database were detected, respectively, in 45.0%, 21.5%, and 37.1% of the nonredundant collection of sequences. This information was employed to functionally annotate the P. tricornutum nonredundant set and to create an internet-accessible queryable diatom EST database. The nonredundant collection was then compared to the putative complete proteomes of the green alga Chlamydomonas reinhardtii, the red alga Cyanidioschyzon merolae, and the centric diatom T. pseudonana. A number of intriguing differences were identified between the pennate and the centric diatoms concerning activities of relevance for general cell metabolism, e.g. genes involved in carbon-concentrating mechanisms, cytosolic acetyl-Coenzyme A production, and fructose-1,6-bisphosphate metabolism. Finally, codon usage and utilization of C and G relative to gene expression (as measured by EST redundance) were studied, and preferences for utilization of C and CpG doublets were noted among the P. tricornutum EST coding sequences.

136 citations

Journal ArticleDOI
TL;DR: The Diatom EST database provides integrated access to expressed sequence tag (EST) data from two eukaryotic microalgae of the class Bacillariophyceae, Phaeodactylum tricornutum and Thalassiosira pseudonana to enable queries over the raw and annotated EST data and retrieval of information through a user-friendly web interface.
Abstract: The Diatom EST database provides integrated access to expressed sequence tag (EST) data from two eukaryotic microalgae of the class Bacillariophyceae, Phaeodactylum tricornutum and Thalassiosira pseudonana. The database currently contains sequences of close to 30,000 ESTs organized into PtDB, the P.tricornutum EST database, and TpDB, the T.pseudonana EST database. The EST sequences were clustered and assembled into a non-redundant set for each organism, and these non-redundant sequences were then subjected to automated annotation using similarity searches against protein and domain databases. EST sequences, clusters of contiguous sequences, their annotation and analysis with reference to the publicly available databases, and a codon usage table derived from a subset of sequences from PtDB and TpDB can all be accessed in the Diatom EST Database. The underlying RDBMS enables queries over the raw and annotated EST data and retrieval of information through a user-friendly web interface, with options to perform keyword and BLAST searches. The EST data can also be retrieved based on Pfam domains, Cluster of Orthologous Groups (COG) and Gene Ontologies (GO) assigned to them by similarity searches. The Database is available at http://avesthagen.sznbowler.com.

101 citations


Cited by
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Journal ArticleDOI
Sabeeha S. Merchant1, Simon E. Prochnik2, Olivier Vallon3, Elizabeth H. Harris4, Steven J. Karpowicz1, George B. Witman5, Astrid Terry2, Asaf Salamov2, Lillian K. Fritz-Laylin6, Laurence Maréchal-Drouard7, Wallace F. Marshall8, Liang-Hu Qu9, David R. Nelson10, Anton A. Sanderfoot11, Martin H. Spalding12, Vladimir V. Kapitonov13, Qinghu Ren, Patrick J. Ferris14, Erika Lindquist2, Harris Shapiro2, Susan Lucas2, Jane Grimwood15, Jeremy Schmutz15, Pierre Cardol16, Pierre Cardol3, Heriberto Cerutti17, Guillaume Chanfreau1, Chun-Long Chen9, Valérie Cognat7, Martin T. Croft18, Rachel M. Dent6, Susan K. Dutcher19, Emilio Fernández20, Hideya Fukuzawa21, David González-Ballester22, Diego González-Halphen23, Armin Hallmann, Marc Hanikenne16, Michael Hippler24, William Inwood6, Kamel Jabbari25, Ming Kalanon26, Richard Kuras3, Paul A. Lefebvre11, Stéphane D. Lemaire27, Alexey V. Lobanov17, Martin Lohr28, Andrea L Manuell29, Iris Meier30, Laurens Mets31, Maria Mittag32, Telsa M. Mittelmeier33, James V. Moroney34, Jeffrey L. Moseley22, Carolyn A. Napoli33, Aurora M. Nedelcu35, Krishna K. Niyogi6, Sergey V. Novoselov17, Ian T. Paulsen, Greg Pazour5, Saul Purton36, Jean-Philippe Ral7, Diego Mauricio Riaño-Pachón37, Wayne R. Riekhof, Linda A. Rymarquis38, Michael Schroda, David B. Stern39, James G. Umen14, Robert D. Willows40, Nedra F. Wilson41, Sara L. Zimmer39, Jens Allmer42, Janneke Balk18, Katerina Bisova43, Chong-Jian Chen9, Marek Eliáš44, Karla C Gendler33, Charles R. Hauser45, Mary Rose Lamb46, Heidi K. Ledford6, Joanne C. Long1, Jun Minagawa47, M. Dudley Page1, Junmin Pan48, Wirulda Pootakham22, Sanja Roje49, Annkatrin Rose50, Eric Stahlberg30, Aimee M. Terauchi1, Pinfen Yang51, Steven G. Ball7, Chris Bowler25, Carol L. Dieckmann33, Vadim N. Gladyshev17, Pamela J. Green38, Richard A. Jorgensen33, Stephen P. Mayfield29, Bernd Mueller-Roeber37, Sathish Rajamani30, Richard T. Sayre30, Peter Brokstein2, Inna Dubchak2, David Goodstein2, Leila Hornick2, Y. Wayne Huang2, Jinal Jhaveri2, Yigong Luo2, Diego Martinez2, Wing Chi Abby Ngau2, Bobby Otillar2, Alexander Poliakov2, Aaron Porter2, Lukasz Szajkowski2, Gregory Werner2, Kemin Zhou2, Igor V. Grigoriev2, Daniel S. Rokhsar2, Daniel S. Rokhsar6, Arthur R. Grossman22 
University of California, Los Angeles1, United States Department of Energy2, University of Paris3, Duke University4, University of Massachusetts Medical School5, University of California, Berkeley6, Centre national de la recherche scientifique7, University of California, San Francisco8, Sun Yat-sen University9, University of Tennessee Health Science Center10, University of Minnesota11, Iowa State University12, Genetic Information Research Institute13, Salk Institute for Biological Studies14, Stanford University15, University of Liège16, University of Nebraska–Lincoln17, University of Cambridge18, Washington University in St. Louis19, University of Córdoba (Spain)20, Kyoto University21, Carnegie Institution for Science22, National Autonomous University of Mexico23, University of Münster24, École Normale Supérieure25, University of Melbourne26, University of Paris-Sud27, University of Mainz28, Scripps Research Institute29, Ohio State University30, University of Chicago31, University of Jena32, University of Arizona33, Louisiana State University34, University of New Brunswick35, University College London36, University of Potsdam37, Delaware Biotechnology Institute38, Boyce Thompson Institute for Plant Research39, Macquarie University40, Oklahoma State University Center for Health Sciences41, İzmir University of Economics42, Academy of Sciences of the Czech Republic43, Charles University in Prague44, St. Edward's University45, University of Puget Sound46, Hokkaido University47, Tsinghua University48, Washington State University49, Appalachian State University50, Marquette University51
12 Oct 2007-Science
TL;DR: Analyses of the Chlamydomonas genome advance the understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella.
Abstract: Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the approximately 120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella.

2,554 citations

Journal ArticleDOI
13 Aug 2010-Science
TL;DR: Although microalgae are not yet produced at large scale for bulk applications, recent advances—particularly in the methods of systems biology, genetic engineering, and biorefining—present opportunities to develop this process in a sustainable and economical way within the next 10 to 15 years.
Abstract: Microalgae are considered one of the most promising feedstocks for biofuels. The productivity of these photosynthetic microorganisms in converting carbon dioxide into carbon-rich lipids, only a step or two away from biodiesel, greatly exceeds that of agricultural oleaginous crops, without competing for arable land. Worldwide, research and demonstration programs are being carried out to develop the technology needed to expand algal lipid production from a craft to a major industrial process. Although microalgae are not yet produced at large scale for bulk applications, recent advances—particularly in the methods of systems biology, genetic engineering, and biorefining—present opportunities to develop this process in a sustainable and economical way within the next 10 to 15 years.

1,712 citations

Journal ArticleDOI
13 Nov 2008-Nature
TL;DR: Analysis of molecular divergence compared with yeasts and metazoans reveals rapid rates of gene diversification in diatoms, and documents the presence of hundreds of genes from bacteria, likely to provide novel possibilities for metabolite management and for perception of environmental signals.
Abstract: Diatoms are photosynthetic secondary endosymbionts found throughout marine and freshwater environments, and are believed to be responsible for around one- fifth of the primary productivity on Earth(1,2). The genome sequence of the marine centric diatom Thalassiosira pseudonana was recently reported, revealing a wealth of information about diatom biology(3-5). Here we report the complete genome sequence of the pennate diatom Phaeodactylum tricornutum and compare it with that of T. pseudonana to clarify evolutionary origins, functional significance and ubiquity of these features throughout diatoms. In spite of the fact that the pennate and centric lineages have only been diverging for 90 million years, their genome structures are dramatically different and a substantial fraction of genes (similar to 40%) are not shared by these representatives of the two lineages. Analysis of molecular divergence compared with yeasts and metazoans reveals rapid rates of gene diversification in diatoms. Contributing factors include selective gene family expansions, differential losses and gains of genes and introns, and differential mobilization of transposable elements. Most significantly, we document the presence of hundreds of genes from bacteria. More than 300 of these gene transfers are found in both diatoms, attesting to their ancient origins, and many are likely to provide novel possibilities for metabolite management and for perception of environmental signals. These findings go a long way towards explaining the incredible diversity and success of the diatoms in contemporary oceans.

1,500 citations

Journal ArticleDOI
TL;DR: This review analyzes the current state of a specific niche of microalgae cultivation; heterotrophic growth in the dark supported by a carbon source replacing the traditional support of light energy.

1,370 citations

Journal ArticleDOI
03 Nov 2005-Nature
TL;DR: It is shown that the role of vitamin B12 in algal metabolism is primarily as a cofactor for vitamin B 12-dependent methionine synthase, and that cobalamin auxotrophy has arisen numerous times throughout evolution, probably owing to the loss of theitamin B12-independent form of the enzyme.
Abstract: Vitamin B12 (cobalamin) was identified nearly 80 years ago as the anti-pernicious anaemia factor in liver, and its importance in human health and disease has resulted in much work on its uptake, cellular transport and utilization. Plants do not contain cobalamin because they have no cobalamin-dependent enzymes. Deficiencies are therefore common in strict vegetarians, and in the elderly, who are susceptible to an autoimmune disorder that prevents its efficient uptake. In contrast, many algae are rich in vitamin B12, with some species, such as Porphyra yezoensis (Nori), containing as much cobalamin as liver. Despite this, the role of the cofactor in algal metabolism remains unknown, as does the source of the vitamin for these organisms. A survey of 326 algal species revealed that 171 species require exogenous vitamin B12 for growth, implying that more than half of the algal kingdom are cobalamin auxotrophs. Here we show that the role of vitamin B12 in algal metabolism is primarily as a cofactor for vitamin B12-dependent methionine synthase, and that cobalamin auxotrophy has arisen numerous times throughout evolution, probably owing to the loss of the vitamin B12-independent form of the enzyme. The source of cobalamin seems to be bacteria, indicating an important and unsuspected symbiosis.

1,120 citations