Global Ocean Sampling Expedition

The expedition grew out of Venter's earlier work on shotgun sequencing of the Sargasso Sea, which had revealed thousands of new genes and species. The GOS aimed to sample a broad range of marine environments to assess global microbial diversity and discover novel genes with potential biotechnological applications. The project was a collaboration between the J. Craig Venter Institute and several academic partners, with funding from the U.S. Department of Energy.

The expedition used the sailing vessel Sorcerer II, which traveled from the North Atlantic through the Panama Canal, across the Pacific, and into the Indian Ocean. Water samples were filtered to collect microbial cells, and DNA was extracted and sequenced using whole-genome shotgun sequencing. The team developed automated sampling and filtration systems to process large volumes of seawater. The resulting data were assembled into a massive metagenomic dataset, representing the largest such dataset at the time.

The GOS identified an estimated 6.12 million predicted proteins, of which about 1.2 million were novel, and more than 1,700 new protein families. The data revealed that microbial diversity in the ocean was far greater than previously thought, with many new phyla and candidate divisions. The expedition also discovered genes involved in phototransduction, such as proteorhodopsins, and genes for antibiotic resistance and degradation of organic compounds. These findings had implications for understanding biogeochemical cycles and for bioprospecting.

The GOS data were made publicly available through the CAMERA (Community Cyberinfrastructure for Advanced Microbial Ecology Research and Analysis) portal, enabling worldwide research. The expedition spurred the development of metagenomics as a field and influenced subsequent large-scale projects like the Tara Oceans expedition. It also raised ethical and policy questions about the ownership and use of genetic resources from international waters, contributing to discussions on marine bioprospecting and the Nagoya Protocol.

The expedition also sampled the Sargasso Sea again, and its data were used to discover a new class of small proteins and to study viral diversity. One notable finding was the presence of genes for rhodopsins in bacteria, which were previously thought to be rare. The project faced criticism for its potential to patent genes, and Venter filed patents on some sequences, sparking controversy. Additionally, the expedition's route included a stop in the Galápagos Islands, where sampling was conducted with special permits. The GOS also contributed to the discovery of the 'rare biosphere' concept, as many of the detected species were present in very low abundance.

Metagenomics

The study of genetic material recovered directly from environmental samples, bypassing the need for culturing organisms.

Shotgun sequencing

A method of DNA sequencing that randomly breaks DNA into small fragments, sequences them, and reassembles the full sequence by overlapping ends.

Proteorhodopsin

A light-driven proton pump found in marine bacteria, used to generate energy from sunlight.

Rare biosphere

The large number of microbial species that exist in very low abundance in an environment, but contribute to overall diversity.