Gene Jumped to All Three Domains of Life

By horizontal gene transfer, an antibacterial gene family has dispersed to a plant, an insect, several fungi, and an archaeon.

By | December 1, 2014

WIKIMIEDIA, NOAAHorizontal gene transfer—the passing of DNA from one organism to another—is a prevalent among bacteria, and has even occurred between distantly related organisms, such as animals and bacteria. In a study published in eLife last week (November 25), researchers demonstrated for the first time that an antibacterial gene family has made the rounds across the three domains of life, from bacteria to archaea and eukaryotes.

“It is the first discovery of a functional antibacterial gene in Archaea,” Vanderbilt University’s Seth Bordenstein, who directed the study, said in a press release.

The results open up a new avenue for searching for antibiotics—in archaea. The gene family Bordenstein’s team studied is an enzyme that can deconstruct the bacterial wall.

Study coauthor Anna-Louise Reysenbach, a Portland State University microbiologist, said in the release that she had often wondered how these archaea, which live near hydrothermal vents, compete for resources with neighboring bacteria. “Through this paper, we show that the smart archaeal ‘bugs’ do so by stealing genes from their bacterial ‘mates’ and competitors. This points to Archaea being good, as yet relatively untapped targets for exploring new antibacterial drugs.”

It’s also possible that the gene transfer helped the archaea gain nutrients not by competition, but by directly feeding upon the bacteria. “Maybe it is not so much carving out a competitor-free niche as helping itself to a bite of bacterium for lunch,” Bill Martin from Heinrich-Heine University in Dusseldorf told National Geographic’s Not Exactly Rocket Science.

Add a Comment

Avatar of: You

You

Processing...
Processing...

Sign In with your LabX Media Group Passport to leave a comment

Not a member? Register Now!

LabX Media Group Passport Logo

Comments

Avatar of: Dr Edo

Dr Edo

Posts: 30

December 18, 2014

Going back through correspondence, back  in Sept of 2005, the following was noted on gene transfer between kingdoms. This was a discussion on the land application of sewage sludge (biosolids) and safety of composted biosolids. This material is often mixed into potting soil. Roughly 60% of all the sewage sludge generated in the US goes to land application, mainly on farmlands or top-dressing for cattle pasture.

See: [13] Ray JL, et al. Experimental methods for assaying natural transformation and inferring horizontal gene transfer. Methods Enzymol. 2005;395:491-520.

 

Additionally, one finds that there is a remultiplication of bacterial numbers within standing sludge, biosolids or compost. Hassen, et al [12] found that, gram-positive bacteria, especially micrococcus, spores of bacilli, and fungal propagules survived, and reached high concentrations in compost. Not only that, "the appearance of gram-negative rods (opportunistic pathogens) during the cooling phase may represent a serious risk for the sanitary quality of the finished product intended for agronomic reuse." Thus, the current EPA Part 503 limits on biosolid marker organisms may have little bearing on the ultimate numbers. For composted sludge and its presumed equivalent to Class-A, there is again a serious gray area.

During composting, the mesophiles (these function at normal body temperatures) can transfer genetic information to thermophiles (these operate above the lethal fever temperatures). The archaea, which are extreme thermophiles (these can take temperatures above the boiling point of water), are recognized as a separate third domain of life together with the bacteria and eukarya. Transfer of plasmids to bacteria from archaea, has been demonstrated [13]. Thus, in theory, it may be possible to develop a MDRB that can survive temperatures found within composting. That such has occurred may be inferred through current studies of the passage of other genetic information during composting. The bugs do find ways to pass-on survival enhancing genetic information.

Popular Now

  1. Can Young Stem Cells Make Older People Stronger?
  2. Thousands of Mutations Accumulate in the Human Brain Over a Lifetime
  3. CRISPR to Debut in Clinical Trials
  4. Two Dozen House Republicans Do an About-Face on Tuition Tax