Horizontal gene transfer: Massive network of recent gene exchange connects bacteria from around the world?
|November 3, 2011||Posted by News under News, horizontal gene transfer|
From “Bacteria May Readily Swap Beneficial Genes: Microbes Trade Genetic Coding for Antibiotic Resistance and More” (ScienceDaily, Nov. 1, 2011), we learn:
In a paper appearing in Nature online Oct. 30, researchers – led by Eric Alm of MIT’s Department of Civil and Environmental Engineering and Department of Biological Engineering – say they’ve found evidence of a massive network of recent gene exchange connecting bacteria from around the world: 10,000 unique genes flowing via HGT among 2,235 bacterial genomes.
HGT is an ancient method for bacteria from different lineages to acquire and share useful genetic information they didn’t inherit from their parents. Scientists have long known about HGT and known that when a transferred gene confers a desirable trait, such as antibiotic resistance or pathogenicity, that gene may undergo positive selection and be passed on to a bacterium’s own progeny, sometimes to the detriment of humans. (For example, the proliferation of antibiotic-resistant strains of bacteria is a very real threat, as seen in the rise of so-called “superbugs.”)
Continuing the work, the researchers are now comparing rates of exchange among bacteria living in separate sites on the same person and among bacteria living on or in people with the same disease. They’re also studying an environmentally contaminated site to see which swapped genes might facilitate microbial cleanup by metal-reducing bacteria.
See also: Ancient bacteria resisted antibiotics they’d never met – jumping genes implicated