"Ehux is the dominant bloom forming coccolithophore and is abundant in oligotrophic oceansthose that have little to sustain lifeso they exert a large effect on global carbon cycling," Read and her colleagues wrote. "Until now, the underlying mechanisms for the considerable physiological and morphological variations between isolates have been elusive. Evidence we present indicates that this capacity can be explained in part by its pan-genome, the first of its kind reported for what was thought to be a single microbial eukaryotic algal species."
The researchers also found that the core gene sets include genes that allow Ehux to thrive in low levels of phosphorus and to assimilate and break down nitrogen-rich compounds. Additionally, the algal genome offers hints that Ehux may be involved in the global sulfur cycle as it is able to produce a compound that can influence cloud formation and therefore climate. The conditions under which Ehux produces the compound and the amounts synthesized are questions the researchers are looking forward to following up on.
"The high diversity within this species indicates that a single strain is unlikely to be typicalor representative of all strains," the team noted. "Future sequencing of phytoplankton isolates will reveal whether this discovery is a unique or more common feature in microalgae. Together, the physiological capacity and genomic plasticity of E. huxleyi make it a powerful model for studying speciation and adaptations to global climate change."
Aside from using the DNA to better understand the alga's role in the planet's carbon and sulfur cycles, Read and her colleagues see the availability of the Ehux genome sequence as an important first step to unlocking the molecular mechanisms that govern the nucleation, growth, and nanoscale patterning of the calcium carbonate s
|Contact: David Gilbert|
DOE/Joint Genome Institute