Bugs repair own DNA to survive eons in ice

clipped from www.abc.net.au Anna Salleh Scientists say they can at last explain how bacteria stay alive in ice for hundreds of thousands of years. Bacteria slow down their metabolism to the point where they produce just enough energy to repair their ageing DNA, say Australian researcher Dr Mike Bunce of Murdoch University in Perth and his international colleagues. The researchers publish their findings today in the Proceedings of the National Academy of Sciences. "We're looking at bacteria that have survived in the permafrost for hundreds of thousands of years. These aren't dead; these are viable cells," says Bunce, a molecular biologist. "If the DNA wasn't being repaired the bacteria would accumulate too much damage to their genome and the cells just would not be viable." "The longest ancient DNA study that's ever been produced got 1000 base pairs of DNA from a dead specimen," says Bunce. "We're getting 4000 base pairs." "That's really the key to the survival mechanism for thousands of years in ice."