Scientists at the Scripps Research Institute in La Jolla have taken a big step toward the laboratory re-creation of the primitive “RNA world” believed to have preceded modern life forms.
“This is probably the first time some of these complex RNA molecules have been synthesized with a ribozyme since the end of the RNA world four billion years ago,” said TSRI Professor Gerald F. Joyce, the senior author of the study.
The new ribozyme can copy short lengths of RNA and make functional RNA molecules with complex structures. Scientists believe such molecules supported primitive life before the evolution of modern biology, which is based on DNA and proteins.
The results from the study were reported this week in the online Early Edition of the Proceedings of the National Academy of Sciences.
In the new study, Joyce and research associate David P. Horning used test-tube evolution techniques to tackle the decades-old challenge of creating a ribozyme that could both replicate and transcribe RNA and thus support an RNA world.
The ribozyme they synthesized can create as many as 40,000 copies of a target RNA molecule within 24 hours.
To generate and sustain a true “RNA world,” the new ribozyme will have to be improved further to enable the replication of longer, more complex RNA molecules—crucially including the ribozyme itself.
The Joyce laboratory is now working toward that goal with further test-tube evolution experiments.
