From a news release (April 30, 2007) describing research by an international team of scientists led by Scripps Institution of Oceanography at UC San Diego and the Department of Energy’s Joint Genome Institute:
The international team’s work, published in the online edition of Proceedings of the National Academy of Sciences, is the first comparison of the genetic makeup of two closely related eukaryotic phytoplankton and the mechanisms that make them biologically similar and distinct.
“Through our research we’ve been trying to understand Ostreococcus’ role in marine ecosystems,” said Palenik, who indicated Ostreococcus cells contain nearly five times the DNA of comparably sized organisms such as cyanobacteria. Genomics has taught us that you can learn much more when you can do a comparison. The first genome is exciting but the second genome is even more exciting because you can suddenly compare organisms and see what each is doing differently and what they are doing the same.”
The researchers comparison of Ostreococcus lucimarinus (recently sequenced by the Department Of Energy’s Joint Genome Institute) and Ostreococcus tauri yielded several surprising results, including the documentation of a “new” chromosome differing between the species. Another chromosome appeared somewhat different between the species and the researchers believe it may serve as a gene transfer “trash can” where foreign DNA is integrated. Yet another difference was the identification of a chromosome featuring the same—albeit rearranged—genes in the two species. The researchers hypothesize that this chromosome may be related to sexual functions because the rearrangements are enough to prevent sex between the species.
Genome report for Ostreococcus tauri:
Genome report for Ostreococcus lucimarinus:
Genome wiki page for Ostreococcus tauri: