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Thursday, July 12, 2012

Jurassic Park in a Petri dish: Scientists bring 500 million-year-old bacteria back to life - what could possibly go wrong?

A 500 million-year-old bacteria has been brought back to life in a laboratory at Georgia Tech in an experiment with echoes of Jurassic Park's disastrous recreation of the dinosaurs.

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,’ said scientist Betül Kaçar, a NASA astrobiology postdoctoral fellow in Georgia Tech.

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

‘The ability to observe an ancient gene in a modern organism as it evolves within a modern cell allows us to see whether the evolutionary trajectory once taken will repeat itself or whether a life will adapt following a different path.’

‘The altered organism wasn’t as healthy or fit as its modern-day version, at least initially,’ said Gaucher, ‘and this created a perfect scenario that would allow the altered organism to adapt and become more fit as it accumulated mutations with each passing day.’

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 Kaçar.

‘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.’

DailyMail

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