Scientists have discovered that marine diatoms, tiny phytoplankton abundant in the sea, have an animal-like urea cycle, and that this cycle enables the diatoms to efficiently use carbon and nitrogen from their environment.
The researchers, from the J. Craig Venter Institute (JCVI) and other institutions, published their findings in this week's issue of the journal Nature.
The team, led by lead author Andrew Allen from JCVI and co-author Chris Bowler, Institute of Biology, Ecole Normale Suprieure, Paris, believes that the cycle could be a reason for the domination of diatoms in marine environments, especially after upwelling events--the upward movement of nutrient rich waters from the deep ocean to the surface.
In response to ocean upwelling, diatoms are able to quickly recover from prolonged periods of nutrient deprivation and rapidly proliferate.
"This study provides fascinating insights into how diatoms have evolved to become the dominant primary producers in many ocean regions," says David Garrison, program director in the National Science Foundation's (NSF) Division of Ocean Sciences, which funded the research along with NSF's Division of Molecular and Cellular Biosciences.
Diatoms have unique cell walls made of silica. They are key organisms for understanding the environmental health of marine ecosystems, and are responsible for much of the carbon and oxygen production in the ocean.
Diatom photosynthesis in ocean environments is also responsible for about one fifth of the oxygen in the atmosphere.
In previous research, Allen, Bowler and colleagues sequenced the genome of the first pennate diatom, Phaeodactylum tricornutum.
In that research, they developed new methods for determining the origin of diatom genes. They also looked at nutrient metabolism in diatoms, beginning with iron metabolism.
Building on that work, Allen and colleagues explored the evolutionary history
|Contact: Cheryl Dybas|
National Science Foundation