Do you ever get tired of filling Darwin’s waste basket?
|October 4, 2013||Posted by News under News, horizontal gene transfer|
If not, this story is not for you. Microbes change genes
ep. 30, 2013 — Sequestered in Antarctica’s Vestfold Hills, Deep Lake became isolated from the ocean 3,500 years ago by the Antarctic continent rising, resulting in a saltwater ecosystem that remains liquid in extreme cold, and providing researchers a unique niche for studying the evolution of the microbes that now thrive under such conditions. Deep Lake’s microscopic inhabitants are dominated by haloarchaea, microbes that require high salt concentrations to grow and are naturally adapted to conditions — at minus 20̊C — that would prove lethally cold to other organisms. In a detailed analysis published online the week of September 30, 2013 in the journal Proceedings of the National Academy of Sciences (PNAS), researchers have, for the first time, been able to get a complete ecological picture of the Deep Lake microbial community.
What distinguishes this “conversation” is that the haloarchaea of Deep Lake exchange the information of DNA not just between species but among distinct genera, and moreover in huge tranches, some 35,000 letters of code, with not a letter out of place. While it may be slow, that give-and-take is chock full of essential information and the word gets around the community. “The long stretches of highly identical shared sequence between the different lake organisms spurred a strong suspicion of potential cross-contamination at first,” said Tanja Woyke, Microbial Program Lead at the DOE JGI and co-author of the study. “By painstaking validation of the manually finished and curated genomes, however, we were able to exclude any process-introduced artifacts and confirm that this is true inter-genera gene exchange.”