Get ready to send the biology textbooks back to the printer. In a new paper published in Nature, Benjamin Van Mooy, a geochemist with the Woods Hole Oceanographic Institution (WHOI) and his colleagues report that microscopic plants growing in the Sargasso Sea have come up with a completely unexpected way of building their cells.
Until now, it was thought that all cells are surrounded by membranes containing molecules called phospholipids oily compounds that contain phosphorus, as well as other basic biochemical nutrients including nitrogen. However, Van Mooy and his colleagues from WHOI, the University of Southern California, University of Hawaii, the Czech Academy of Sciences, the Bermuda Institute of Ocean Sciences, University of Southern Maine, and the Centre d'Ocanologie de Marseille have found phytoplankton in the Sargasso Sea that make their cell membranes without using phospholipids, using non-phosphorus-containing 'substitute lipids' instead. These substitute lipids were once regarded as merely a molecular peculiarity of phytoplankton grown in the laboratory, but are now recognized to be used by phytoplankton throughout the world's ocean.
Substitute lipids "are the most abundant membrane molecules in the sea and they were essentially unknown until now," says Van Mooy, whose work at WHOI was supported by the National Science Foundation, the Office of Naval Research, and the WHOI Ocean Life Institute. The finding could help rewrite the fundamentals of cell biochemistry.
The Sargasso Sea is in the middle of the Atlantic Ocean an area known for its short supply of phosphorus and nitrogen. A molecule of phosphorus dissolved in the Sargasso Sea remains there for perhaps an hour or two before a phosphorus-starved cell greedily absorbs it. For comparison, in the Pacific Ocean phosphorus may linger for nearly a year before being used by plankton.
But oceanographers find phytoplankton living and growing rather well in
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Woods Hole Oceanographic Institution