Pages

Friday, July 27, 2012

500mn-year-old bacteria recreated in lab

From ZeeNews: 500mn-year-old bacteria recreated in lab

London: A 500 million-year-old bacteria has been brought back to life in a laboratory at Georgia Tech in an experiment with echoes of Stephen Spielberg’s Jurassic Park, where scientists recreated dinosaurs using ancient DNA.

The researchers have resurrected a 500-million-year-old gene and inserted it into a modern E Coli bacteria.

The ‘Frankenstein’ germ has thrived. In the lab, the creation has now lived through 1,000 generations.

The scientists hope to find out whether the ‘ancient’ bacteria will evolve the same way it did ‘first time round’ - or whether it will evolve into a different, new organism.

“This is as close as we can get to rewinding and replaying the molecular tape of life,” the Daily Mail quoted scientist Betul Kacar, a NASA astrobiology postdoctoral fellow in Georgia Tech, as saying.

The new ‘chimeric’ bacteria have mutated rapidly - and some have become stronger and healthier than today’s germs.

The growth rate eventually increased and, after the first 500 generations, the scientists sequenced the genomes of all eight lineages to determine how the bacteria adapted.

Not only did the fitness levels increase to nearly modern-day levels, but also some of the altered lineages actually became healthier than their modern counterpart.

When the researchers looked closer, they noticed that every EF-Tu gene did not accumulate mutations.

Instead, the modern proteins that interact with the ancient EF-Tu inside of the bacteria had mutated and these mutations were responsible for the rapid adaptation that increased the bacteria’s fitness.

In short, the ancient gene has not yet mutated to become more similar to its modern form, but rather, the bacteria found a new evolutionary trajectory to adapt.

These results were presented at the recent NASA International Astrobiology Science Conference

The scientists will continue to study new generations, waiting to see if the protein will follow its historical path or whether it will adopt via a novel path altogether.

“We think that this process will allow us to address several longstanding questions in evolutionary and molecular biology,” said Kacar.

“Among them, we want to know if an organism’s history limits its future and if evolution always leads to a single, defined point or whether evolution has multiple solutions to a given problem,” he noted.

No comments:

Post a Comment