Creating RNA In Water Puddle Gives Insight Into Prebiotic Earth

Much before other forms of life came into existence, RNA and DNA components came together to form chemicals. Experts used simple laboratory reactions in water to create candidates for missing links that led to life formations.

Scientists believe that before DNA was used to store genetic information, RNA was harnessed. This might have been preceded by proto-RNA that exhibited varying yet similar nucleotides.

"Early Earth was a messy laboratory where probably many molecules like those needed for life were produced," said Nicholas Hud, a professor at the Georgia Institute of Technology who led the study. "Some survived and prospered, while others eventually vanished. That goes for the ancestors of RNA, too."

With proto-nucleotides employing a couple of molecules of barbituric acid and melamine, the scientists discovered results very similar to two of RNA's nucleotides. This encouraged researchers to surmise that both ingredients, which are thought to have been in high supply during a prebiotic earth, may have been forerunners of RNA nucleotides.

"They would have been well suited for primitive information coding," Hud said.

However, more research is needed.

"To claim ancestry, we would have to show a mechanism by which these nucleotides we made in the lab could turn into the existing nucleotides in RNA," said Ram Krishnamurthy, co-author of the study and a researcher from Scripps Research Institute in La Jolla, Calif. "It's a complex path that we'd have to at least design on paper, and we're not there."

"There are umpteen possibilities of how that mechanism could have happened," he continued. "Barbituric acid and melamine may have been place holders that dropped out and allowed adenine and uracil to come together with ribose."

The conclusions arrived at will point the way to discovering chemical evolution as well as the formation of the first life forms on Earth.

"If you want to look at what brought about these properties of life you have to go back and consider all the other molecules that would have been present and see how they would have facilitated the molecules that are present in life today," Krishnamurthy said.

The findings were published in the April 25 issue of Nature Communications.