Their paper is published in the Nov. 6 issue of Science.,
E. huxleyi performs photosynthesis"just like plants," says Van Mooy. "They suck up carbon dioxide." In doing so, they reduce the amount of CO2 released into the atmosphere. They form a calcium carbonate shell, also helping to regulate the carbon cycle.
If viruses are killing off phytoplankton, this can increase greenhouse emissions, Van Mooy suggests. "That's important because if viruses infect a whole bunch of cells, then they can't perform photosynthesis, they can't take up carbon dioxide."
In April 2008, Van Mooy's team visited the sites of E. huxleyi blooms during a research cruise between Woods Hole and Bermuda and collected samples for lipid analysis back in the laboratory.
They immediately recognized lipids that were just like those in virally infected E. huxleyi cells grown by the Rutgers team. Helen Fredricks, a research associate with Van Mooy, carried out the lipid analyses at WHOI. "Seeing this viral lipid appear during the course of infection was amazing, and then we found it in the ocean too. We were celebrating in the lab that day."
Adds Vardi: "Viruses are really important players in regulating phytoplankton blooms. We zoom into the bloom and try to understand the interaction between the viruses and host, which is this really important, cosmopolitan, bloom-forming species."
After isolating the viral lipids, the team found that the lipids alone were able to bring about the symptoms of viral infection in the phytoplankton. "The lipids themselves act just like the virus," says Van Mooy. "We can cause the phytoplankton to die by just giving the lipids."
This alone was enough to excite the team. "Now we have a biological marker that we can go out on a ship and look for and identify where this [infection of phytoplankton] is happening and learn how to
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Woods Hole Oceanographic Institution