NASA: DNA Building Blocks from Space?

Earlier this month NASA-funded researchers at NASA’s Astrobiology Analytical Laboratory at the Goddard Space Flight Center added to the growing body of evidence that the basics of DNA could have formed in space. Since the 1960’s people have been discovering the building blocks of DNA in meteorites around the world.

The team, lead by Dr. Michael Callahan ground up samples of carbon-rich meteorites mostly retrieved from Antarctica and found components of DNA called nucleobases. Here, he discusses the research:

These components, called nucleobase analogs have the same core molecules as nucleobases but with a structure added or removed. Researchers wanted to confirm a plausible mechanism, and as such experiments were conducted to attempt to generate the same set of nucleobases and nucleobase analogs without using a biological chemical reaction, using hydrogen cyanide, ammonia, and water. The experiments were successful.

Meteorites contain a large variety of nucleobases, an essential building block of DNA. Credit:NASA/Goddard Space Flight Center

It’s unlikely that these analogs were the result of Earth-based life given that none except one of the nucleobase analogs found are not used in biology; Further evidence through the analysis of an ice sample from Antarctica, where most of the meteorites were recovered measured the quantity of the two nucleobases, plus hypoxanthine and xanthine in parts per trillion; compared to the meteorites where they were generally present at several parts per billion. More significantly, none of the nucleobase analog molecules present in the meteorite were found in the ice sample – This was the same for a soil sample taken near where a meteorite was found in Australia.

The latest paper was published in the Proceedings of the National Academy of Sciences of the United States of America; The team includes Callahan and Drs. Jennifer C. Stern, Daniel P. Glavin, and Jason P. Dworkin of NASA Goddard’s Astrobiology Analytical Laboratory; Ms. Karen E. Smith and Dr. Christopher H. House of Pennsylvania State University, University Park, Pa.; Dr. H. James Cleaves II of the Carnegie Institution of Washington, Washington, DC; and Dr. Josef Ruzicka of Thermo Fisher Scientific, Somerset, N.J. The research was funded by the NASA Astrobiology Institute, the Goddard Center for Astrobiology, the NASA Astrobiology: Exobiology and Evolutionary Biology Program, and the NASA Postdoctoral Program.

Original Article: NASA Researchers: DNA Building Blocks Can Be Made in Space

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