Biodiversidad (PLoS Biology)

En el volumen 5 (issue 3) de marzo del 2007 de la revista PLoS Biology hay una serie de artículos con el trabajo del Global Ocean Sample (GOS) Expedition, una expedición liderada por J. Craig Venter que ha recogido muestras oceánicas de superficie de todo el mundo y se ha dedicado a secuenciar y analizar partes de genomas que en ellas encontraba. Los trabajos con los hiperlinks al texto completo son:

The Sorcerer II Global Ocean Sampling Expedition: Northwest Atlantic through Eastern Tropical Pacific.
Douglas B. Rusch, Aaron L. Halpern, Granger Sutton, Karla B. Heidelberg, Shannon Williamson, Shibu Yooseph, Dongying Wu, Jonathan A. Eisen, Jeff M. Hoffman, Karin Remington, Karen Beeson, Bao Tran, Hamilton Smith, Holly Baden-Tillson, Clare Stewart, Joyce Thorpe, Jason Freeman, Cynthia Andrews-Pfannkoch, Joseph E. Venter, Kelvin Li, Saul Kravitz, John F. Heidelberg, Terry Utterback, Yu-Hui Rogers, Luisa I. Falcón, Valeria Souza, Germán Bonilla-Rosso, Luis E. Eguiarte, David M. Karl, Shubha Sathyendranath, Trevor Platt, Eldredge Bermingham, Victor Gallardo, Giselle Tamayo-Castillo, Michael R. Ferrari, Robert L. Strausberg, Kenneth Nealson, Robert Friedman, Marvin Frazier, J. Craig Venter
Link al artículo.

The Sorcerer II Global Ocean Sampling Expedition: Expanding the Universe of Protein Families
Shibu Yooseph, Granger Sutton, Douglas B. Rusch, Aaron L. Halpern, Shannon J. Williamson, Karin Remington, Jonathan A. Eisen, Karla B. Heidelberg, Gerard Manning, Weizhong Li, Lukasz Jaroszewski, Piotr Cieplak, Christopher S. Miller, Huiying Li, Susan T. Mashiyama, Marcin P. Joachimiak, Christopher van Belle, John-Marc Chandonia, David A. Soergel, Yufeng Zhai, Kannan Natarajan, Shaun Lee, Benjamin J. Raphael, Vineet Bafna, Robert Friedman, Steven E. Brenner, Adam Godzik, David Eisenberg, Jack E. Dixon, Susan S. Taylor, Robert L. Strausberg, Marvin Frazier, J. Craig Venter
Link al artículo.

Structural and Functional Diversity of the Microbial Kinome
Natarajan Kannan, Susan S. Taylor, Yufeng Zhai, J. Craig Venter, Gerard Manning
Link al artículo.

Destaco el último párrafo del segundo de los artículos que refiere la enorme diversidad encontrada y la necesidad de llevar este tipo de proyecto a otros ambientes:
"The GOS dataset has demonstrated the usefulness of large-scale environmental shotgun sequencing projects in exploring proteins. These projects offer an unbiased view of proteins and protein families in an environmental sample. However, it should be noted that the GOS data reported here are limited to mostly ocean surface microbes. Even with this targeted sampling a tremendous amount of diversity is added to known families, and there is evidence for a large number of novel families. Additional data from larger filter sizes (that will sample more eukaryotes) coupled with metagenomic studies of different environments like soil, air, deep sea, etc. will help to achieve the ultimate goal of a whole-earth catalog for proteins."

Y el final de la discusión del primer artículo que apunta a lo poco que conocemos acerca de como varian las poblaciones microbianas y del papel que pueden jugar la transferencia horizontal de genes y los islotes (o islas) hipervariables:
"In conclusion, this study reveals the wealth of biological information that is contained within large multi-sample environmental datasets. We have begun to quantify the amount and structure of the variation in natural microbial populations, while providing some information about how these factors are structured along phylogenetic and environmental factors. At the same time, many questions remain unanswered. For example, although microbial populations are structured and therefore genetically isolated, we do not understand the mechanisms that lead to this isolation. Their isolation seems contradictory given overwhelming evidence that horizontal gene transfer associated with hypervariable islands is a common phenomenon in marine microbial populations. Whatever the mechanism, the role and rate at which gene exchange occurs between populations will be crucial to understanding population structure within microbial communities and whether these communities are chance associations or necessary collections. The hypervariable islands could be a source for tremendous genetic innovation and novelty as evidenced by the rate of discovery of novel protein families in the GOS dataset. However, it is not clear whether these entities are the main source of this novelty or whether this novelty resides in the vast numbers of rare microbes that cannot be practically accessed using current metagenomic approaches. Altogether, this research reaffirms our growing wealth and complexity of data and paucity of understanding regarding the biological systems of the oceans."