Sunday, November 22, 2009

Scientists Create RNA Chains in the Lab

Cross-posted here

A group of Italian scientists have reconstructed a possible early step in evolution. Ernesto Di Mauro and his team used cyclic nucleotides to create long strands of RNA from individual units using primarily water. Many evolutionary biologists believe that RNA was one of the first biological molecules to be present on Earth. The nucleotides used by the scientists merged together in water to form polymers over 100 nucleotides long.

The nucleotides that would have been present on prebiotic Earth would have been based upon simple chemicals and would have been quite easy to form chains. It has been previously shown that RNA precursors can self-assemble into linear polymers but scientists as of yet do not know the origin of informational polymers. Formamide chemistry has the potential to gather all of the precursors needed to form pregenetic informational polymers.

Di Mauro and his team thought that “the solution must have relied on a simple but robust process.” This ideal is why a formamide solution was utilized; it is simple and relatively stable yet still is reactive. The processes used by the team show that the formation of cyclic monophosphate nucleosides is chemically simple and prebiotically plausible. Like prebiotic Earth the solution temperatures used were around 40-60 °C. These nucleotides are similar to those that make up individual pieces of RNA or DNA (A, T, G, and C) with the difference of an extra chemical bond and a ring-like shape. The chains that were made in the lab were done without the use of enzymes or inorganic catalysts to set off the reactions as prebiotic conditions would require.

The non-enzymatic pregenetic polymerization done in this study could have taken place in warm little pond conditions like those depicted by Darwin in Origin of Species. As more information is studied in labs like those of Di Mauro and his collegues the closer scientists are to understanding not only the conditions of prebiotic Earth but the chemical processes which gave rise to biological life. Continuing research into chemical biology will help scientists know just how rare of an even life arising is and help determine the likelihood of it arising elsewhere in the universe as well.

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