Menu

RNA-DNA Chimeras Might Have Supported the Origin of Life on Earth

A new study finds mixtures of nucleotide types, rather than pure systems, are more likely to yield the building blocks of life.

Sep 17, 2019
Jef Akst

ABOVE: © ISTOCK.COM, POLESNOY

Molecules that combine elements of RNA and DNA, so-called chimeric molecules, may have been an important step in the emergence of life on Earth from the primordial soup that existed billions of years ago, according to a study published yesterday (September 16) in Nature Chemistry.

The work, reported by Scripps Research Institute chemist Ramanarayanan Krishnamurthy and his postdoc Subhendu Bhowmik, came out of research exploring the transition from RNA-based lifeforms—commonly thought to be the first life on the planet—to the DNA-based life that is ubiquitous today. In making chimeric RNA-DNA molecules, Krishnamurthy and colleagues previously found that they have some advantages that might make them better candidates than pure RNA for the first reproducing molecules.

“There are times when we have mixtures, rather than just the isolated reactants that people typically use, and we get better results,” Nicholas Hud, a chemist at Georgia Tech who collaborated with Krishnamurthy on the earlier RNA-DNA chimera work but was not involved in the new study, tells Quanta. When mixtures are taken into consideration, the emergence of life on Earth in some ways “is not as hard as we might think it is.”

The key advantage of the RNA-DNA chimeras is their instability, the team published in 2016. Although RNA is commonly cited as the most likely first self-replicating molecule, getting it to perform the task in the lab has been challenging, in large part because the double-stranded molecule is so stable that the two stands do not want to unwind. “It’s a real challenge,” Sutherland tells Quanta. “It’s held the field back for a long time.” (Quanta is published by the same organization, the Simons Foundation, that funds an origin-of-life research group that Sutherland and Krishnamurthy are part of.)

See “RNA World 2.0

In the newly published study, Krishnamurthy and Bhowmik found that the molecules consisting of both RNA and DNA components formed weaker bonds between the strands, allowing them to easily separate for replication. Then, as new strands formed, they preferentially bonded to like structures, yielding molecules of pure RNA and pure DNA. Similarly, chimeric molecules of RNA and an artificial nucleic acid known as TNA, which researchers speculate may represent a molecule that existed before RNA, were better able to yield nucleic acids composed entirely of RNA or TNA components than when starting with RNA or TNA alone.

“If you let the reactions happen in a mixture, they automatically give you the molecules you’re looking for without you actually wanting it,” Krishnamurthy tells Quanta.

Jef Akst is the managing editor of The Scientist. Email her at jakst@the-scientist.com

October 2019

Brain Fog

Air Pollution May Cause Cognitive Decline

Marketplace

Sponsored Product Updates

Lonza’s MODA-ES™ Platform helps Nephron Pharmaceuticals move from paper to an EBR in nine months - Case study to be presented at 2019 ISPE Annual Meeting 
Lonza’s MODA-ES™ Platform helps Nephron Pharmaceuticals move from paper to an EBR in nine months - Case study to be presented at 2019 ISPE Annual Meeting 
·        Lonza has partnered with Nephron Pharmaceuticals Corporation to implement Lonza’s next-generation MODA-ES™ EBR Platform to streamline manufacturing compliance reporting· The MODA-ES™ Platform was implemented at Nephron in an aggressive nine-month time frame, improving operational efficiency and enabling a significant product line expansion·        Full results of the collaboration will be co-presented by Lonza and Nephron at the 2019 ISPE Annual Meeting & Expo in Las Vegas, Nevada
Understanding T-cell polyfunctionality: How single cell proteomics data drive CAR-T cell therapy research and development
Understanding T-cell polyfunctionality: How single cell proteomics data drive CAR-T cell therapy research and development
Vladimir Senyukov, Director of BioAnalytical Development at Precision Biosciences, talks about investigating T-cell cytokine production using single cell proteomics in order to unlock the therapeutic potential of allogenic CAR-T cells.
Zymo Research launches new RNA-Seq library prep kit
Zymo Research launches new RNA-Seq library prep kit
Zymo Research is excited to announce the fastest and easiest total RNA-Seq library prep kit that allows users to go from sample to sequencer in a single day!