Easy Ultraviolet Life

In order to decipher how RNA and DNA formed the origins of life on Earth, scientists have made many attempts to recreate, in a modeled lab setting, these building blocks of life. It was assumed that the single-stranded RNA, which is less complex then its double-stranded counterpart DNA, required a particularly harsh primordial setting in order to develop.

Though three out of the four letter code of RNA (adenine A; cytosine C; and uracil U) could be created relatively simply by heating a preliminary compound with naturally occurring catalysts, the forth letter of the code, guanine (G), could not be created with the same process--until now.

Researchers from the Georgia Institute of Technology and the University of Roma, have discovered that the missing catalyst in guanine production was ultraviolet light. By working with this catalyst, the formation of RNA has been found to be created by much easier means than were originally hypothesized, suggesting that the origin of life on Earth may not have been as difficult as we thought.

Originally the three codes (A, C, and U), could only be synthesized by heating formamide, which is used as a synthetic primordial soup, to 160 degrees Celsius creating these nucleic acid components, but never the aloof guanine (G) which only appeared in minuscule amounts. But by subjecting a solution of formamide to ultraviolet radiation during heating, the trace amounts of guanine yield was greatly enhanced when minerals and photons were used together. The same process caused significant increases in the production of adenine, and a related molecule called hypoxanthine, creating a strong foundation for the chemical components of life prior to the appearance of DNA and protein enzymes.

The study also shows that guanine, adenine, and hypoxanthine can be produced at temperatures 30 degrees lower than originally thought, even without the appearance of minerals, as long as these photons were added to the process. The new breakthrough expands the range of chemical conditions in which we know life is possible.

Image: "precious"  by freakpower on Flickr courtesy of Creative Commons Licensing.