Artificial molecule ‘evolves in lab’

Artificial molecule ‘evolves in lab’
PTI
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First Published: Fri, Jan 09 2009. 03 27 PM IST
Updated: Fri, Jan 09 2009. 03 27 PM IST
Washington: Scientists have produced an artificial molecule in the lab which can perform the essential function of life, called self-replication, a breakthrough they claim could soon shed light on the origin of life on Earth.
A team at the Scripps Research Institute has made the chemical out of ribonucleic acid (RNA) as it is believed that early life stored information in this sister molecule to DNA, and RNA molecules can catalyse chemical reactions.
“We’re trying to jump in at the last signpost we have back there in the early history of life,” the ‘New Scientist´ quoted lead scientist Gerald Joyce as saying.
In fact, the team created its own molecule from scratch, called R3C. It performed a single function: Stitching two shorter RNA molecules to create a clone of itself. Further lab tinkering made this molecule better at copying itself, but this is not the same as bringing it to life.
To improve R3C, the scientists redesigned the molecule to forge a sister RNA that could itself join two other pieces of RNA into a functioning ribozyme. In that way, each molecule makes a copy of its sister a process called cross-replication.
And, to evolve their molecule by natural selection, they mutated sequences of the RNA building blocks, so that 288 possible ribozymes could be built by just mixing and matching different pairs of shorter RNAs.
What came out bore an eerie resemblance to Charles Darwin’s theory of survival of the fittest -- a few sequences proved winners, most losers. “The victors emerged because they could replicate fastest while surrounded by competition,” he said.
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First Published: Fri, Jan 09 2009. 03 27 PM IST