San Francisco State Professor Teams Up To Sequence Ocean Diatom

Frances Wilkerson, SFSU lecturer and senior research scientist at the Romberg Tiburon Center for Environmental Studies, was among a group of 45 distinguished marine scientists, botanists and geneticists from several countries who recently became the first to sequence a marine phytoplankton species. The group, which was selected by the Joint Genome Institute, sequenced the oceanic diatom Thalassiosira pseudonana. Their findings, published in the Oct. 1 issue of SCIENCE, are expected to accelerate work in bio- and nanotechnology as well as the marine sciences.

Among the team's surprising observations is that T. pseudonana has the genes for a urea cycle, a nitrogen waste pathway common to animal species but never before seen in diatoms and other photosynthetic organisms. Diatoms, which are a tiny fraction of the size of a human hair, are considered the base of the short food web that supports large-scale coastal fisheries. Photosynthesis by marine diatoms is believed to generate as much as 40 percent of the 40 to 50 billion tons of organic carbon produced each year in the Earth's oceans. Scientists believe that the marine diatom's role in global carbon cycling is comparable to that of all terrestrial rain forests combined.

The successful sequencing of ocean diatoms bodes well for Silicon Valley industries. Unique to the diatom is its ornately patterned silicified cell wall which displays nano-structures so fine that they have been used to test the resolution of optical microscopes. "Once we understand how it is that the diatom deposits silicon to form its ornate cell walls," Wilkerson notes, "the work of material scientists in the field of microchip nanotechnology will significantly advance." For marine scientists, genome sequencing will soon be a common tool to test theories in ocean ecology and no doubt add to researchers' knowledge of the structure of oceanic ecosystems.

Much like the Human Genome Project, Wilkerson says that the Diatom Genome Project "opens the door to years and years of important work by hundreds of scientists around the world." It has already facilitated several projects in her lab at SFSU. Wilkerson adds that SFSU's Romberg Tiburon Center is "well known for its molecular approach to understanding the ocean" and was recently awarded funding by the National Science Foundation to improve its molecular genetic instrumentation.

Contact: Denize Springer, 415/405-3803 or 415/338-1665, denize@sfsu.edu