Advanced search
1 file | 1.19 MB

Genome analysis of the smallest free-living eukaryote Ostreococcus tauri unveils many unique features

Author
Organization
Abstract
The green lineage is reportedly 1,500 million years old, evolving shortly after the endosymbiosis event that gave rise to early photosynthetic eukaryotes. In this study, we unveil the complete genome sequence of an ancient member of this lineage, the unicellular green alga Ostreococcus tauri (Prasinophyceae). This cosmopolitan marine primary producer is the world's smallest free-living eukaryote known to date. Features likely reflecting optimization of environmentally relevant pathways, including resource acquisition, unusual photosynthesis apparatus, and genes potentially involved in C-4 photosynthesis, were observed, as was downsizing of many gene families. Overall, the 12.56-Mb nuclear genome has an extremely high gene density, in part because of extensive reduction of intergenic regions and other forms of compaction such as gene fusion. However, the genome is structurally complex. It exhibits previously unobserved levels of heterogeneity for a eukaryote. Two chromosomes differ structurally from the other eighteen. Both have a significantly biased G+C content, and, remarkably, they contain the majority of transposable elements. Many chromosome 2 genes also have unique codon usage and splicing, but phylogenetic analysis and composition do not support alien gene origin. In contrast, most chromosome 19 genes show no similarity to green lineage genes and a large number of them are specialized in cell surface processes. Taken together, the complete genome sequence, unusual features, and downsized gene families, make O. tauri an ideal model system for research on eukaryotic genome evolution, including chromosome specialization and green lineage ancestry.
Keywords
EVOLUTION, PRASINOPHYCEAE, CHLOROPHYTA, DIVERSITY, PACIFIC-OCEAN, QUANTITATIVE PCR, MARINE ECOSYSTEMS, PROCHLOROCOCCUS ECOTYPES, RIBOSOMAL-RNA GENE, GREEN-ALGA OSTREOCOCCUS, gene prediction, Prasinophyceae, green alga, genome heterogeneity, genome sequence

Downloads

  • (...).pdf
    • full text
    • |
    • UGent only
    • |
    • PDF
    • |
    • 1.19 MB

Citation

Please use this url to cite or link to this publication:

Chicago
Derelle, Evelyne, Conchita Ferraz, Stephane Rombauts, Pierre Rouzé, Alexandra Z Worden, Steven Robbens, Frédéric Partensky, et al. 2006. “Genome Analysis of the Smallest Free-living Eukaryote Ostreococcus Tauri Unveils Many Unique Features.” Proceedings of the National Academy of Sciences of the United States of America 103 (31): 11647–11652.
APA
Derelle, E., Ferraz, C., Rombauts, S., Rouzé, P., Worden, A. Z., Robbens, S., Partensky, F., et al. (2006). Genome analysis of the smallest free-living eukaryote Ostreococcus tauri unveils many unique features. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 103(31), 11647–11652.
Vancouver
1.
Derelle E, Ferraz C, Rombauts S, Rouzé P, Worden AZ, Robbens S, et al. Genome analysis of the smallest free-living eukaryote Ostreococcus tauri unveils many unique features. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. 2006;103(31):11647–52.
MLA
Derelle, Evelyne, Conchita Ferraz, Stephane Rombauts, et al. “Genome Analysis of the Smallest Free-living Eukaryote Ostreococcus Tauri Unveils Many Unique Features.” PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 103.31 (2006): 11647–11652. Print.
@article{352045,
  abstract     = {The green lineage is reportedly 1,500 million years old, evolving shortly after the endosymbiosis event that gave rise to early photosynthetic eukaryotes. In this study, we unveil the complete genome sequence of an ancient member of this lineage, the unicellular green alga Ostreococcus tauri (Prasinophyceae). This cosmopolitan marine primary producer is the world's smallest free-living eukaryote known to date. Features likely reflecting optimization of environmentally relevant pathways, including resource acquisition, unusual photosynthesis apparatus, and genes potentially involved in C-4 photosynthesis, were observed, as was downsizing of many gene families. Overall, the 12.56-Mb nuclear genome has an extremely high gene density, in part because of extensive reduction of intergenic regions and other forms of compaction such as gene fusion. However, the genome is structurally complex. It exhibits previously unobserved levels of heterogeneity for a eukaryote. Two chromosomes differ structurally from the other eighteen. Both have a significantly biased G+C content, and, remarkably, they contain the majority of transposable elements. Many chromosome 2 genes also have unique codon usage and splicing, but phylogenetic analysis and composition do not support alien gene origin. In contrast, most chromosome 19 genes show no similarity to green lineage genes and a large number of them are specialized in cell surface processes. Taken together, the complete genome sequence, unusual features, and downsized gene families, make O. tauri an ideal model system for research on eukaryotic genome evolution, including chromosome specialization and green lineage ancestry.},
  author       = {Derelle, Evelyne and Ferraz, Conchita and Rombauts, Stephane and Rouz{\'e}, Pierre and Worden, Alexandra Z and Robbens, Steven and Partensky, Fr{\'e}d{\'e}ric and Degroeve, Sven and Echeyni{\'e}, Sophie and Cooke, Richard and Saeys, Yvan and Wuyts, Jan and Jabbari, Kamel and Bowler, Chris and Panaud, Olivier and Pi{\'e}gu, Beno{\^i}t and Ball, Steven G and Ral, Jean-Philippe and Bouget, Fran\c{c}ois-Yves and Piganeau, Gwenael and De Baets, Bernard and Picard, Andr{\'e} and Delseny, Michel and Demaille, Jacques and Van de Peer, Yves and Moreau, Herv{\'e}},
  issn         = {0027-8424},
  journal      = {PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA},
  language     = {eng},
  number       = {31},
  pages        = {11647--11652},
  title        = {Genome analysis of the smallest free-living eukaryote Ostreococcus tauri unveils many unique features},
  url          = {http://dx.doi.org/10.1073/pnas.0604795103},
  volume       = {103},
  year         = {2006},
}

Altmetric
View in Altmetric
Web of Science
Times cited: