Early Cyanobacteria Samples Tested For Building Blocks Of Life
November 13, 2012

Scientists Discover Possible Building Blocks Of Ancient Genetic Systems

April Flowers for redOrbit.com - Your Universe Online

Before DNA became the Earth's primary genetic material over 3.5 million years ago, scientists believe forms of life used RNA to encode genetic instructions. What came before RNA, though?

A research team from Weber State University and the Stockholm University think the answer might be N-(2-aminoethyl)glycine AEG, a small molecule that when linked forms a hypothetical backbone for peptide nucleic acids. Scientists hypothesize that peptide nucleic acids are the first genetic molecules. The pharmaceutical industry has studied synthetic AEG as a possible gene silencer to stop or slow certain genetic diseases. Up until now, however, AEG has been unknown from nature.

The research team discovered AEG within cyanobacteria, which are believed to be some of the most primitive organisms on Earth. During hot summer months, cyanobacteria appear as mats of scums on the surface of reservoirs and lakes. They can handle widely ranging habitats, from the hot springs of Yellowstone to the Arctic tundra.

“Our discovery of AEG in cyanobacteria was unexpected,” explains Dr. Paul Alan Cox, part of the American team based at the Institute for Ethnomedicine. The findings of this study were published in PLOS ONE.

“While we were writing our manuscript,” Cox says, “we learned that our colleagues at the Stockholm University Department of Analytical Chemistry had made a similar discovery, so we asked them to join us on the paper.”

The team analyzed pristine cyanobacteria cultures from the Pasteur Culture Collection to determine how widespread AEG production is among cyanobacteria. They collected further samples from Guam, Japan, and Qatar, along with samples gathered in the Gobi desert by famed Wyoming naturalist Derek Craighead. All of the samples tested produced AEG.

The samples were retested by the Stockholm University group with identical results: all samples of the cyanobacteria produced AEG. With confirmation, the analysis seems certain. What is unclear, however, is the significance this finding has for studies of the earliest forms of life on earth. For example, does the production of AEG by cyanobacteria represent an echo of the earliest life on earth?

“We just don´t have enough data yet to draw that sort of conclusion,” reports Cox. “However the pharmaceutical industry has been exploring synthetic AEG polymers for potential use in gene silencing, so I suspect we have much more to learn.”