DNA precursor found in Jackson
By Benjamin Graham, Jackson Hole, Wyo.
November 13, 2012
Bacteria found as near as the geysers of Yellowstone National Park and as far away as the Arctic may contain one of Earth’s earliest forms of genetic material, according to scientists in Jackson.
A molecule discovered in bluish-green cyanobacteria by the Institute for Ethnomedicine could be a precursor to DNA, according to a study released last week in the journal PloS One. Cyanobacteria is a bacterium that lives through photosynthesis, using sunlight to create its own food.
The molecule, called AEG, hypothetically can be linked into chains to form Peptide Nucleic Acids, an early form of DNA that scientists believe exists, but whose occurrence they have never seen in nature.
Until scientists from the Institute for Ethnomedicine discovered AEG, it had only been created synthetically by pharmaceutical companies.
The scientists found the material in bluish-green, single-celled organisms known as cyanobacteria, which are believed to be some of the earliest living organisms on Earth.
“Everybody knows about DNA,” said Dr. Sandra Banack, senior scientist at the Institute for Ethnomedicine. “It’s thought that before DNA, cells could have used RNA” to transfer genetic information.
“It has been hypothesized that before RNA, there could have been something else,” Banack said.
That something else might be AEG.
The researchers stumbled on the material while looking for links between cyanobacteria and ALS, also known as Lou Gehrig’s disease.
While using a mass spectrometer to identify and measure the mass of BMAA, a toxic particle in the bacteria, an unknown molecule kept reappearing.
“It’s got the same number and types of atoms as BMAA, but they’re in a different arrangement,” said Dr. James Metcalf, a visiting researcher at the Institute for Ethnomedicine.
The finding puzzled the scientists enough for them to analyze untainted cy-anobacterial cultures from the Pasteur Culture Collection in Paris. The results were the same.
“It kept grabbing our attention,” Banack said. “We kept wondering what it was.”
The scientists aren’t certain at this point if AEG was used by early life forms to transfer genetic information, but it has been proven that the bacteria produce the hitherto undiscovered molecule.
“We want to find out where exactly AEG is in the cells and how it’s arranged in cells to see if there’s any link between genes and AEG,” Metcalf said.