Campus: San Francisco State University -- October 13, 2004
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
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
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,