The world's oldest bacteria

Aug 27, 2007

A research team has for the first time ever discovered DNA from living bacteria that are more than half a million years old. Never before has traces of still living organisms that old been found. The exceptional discovery can lead to a better understanding of the ageing of cells and might even cast light on the question of life on Mars.

The discovery is being published in the current issue of PNAS (Proceedings of The National Academy of Sciences). The discovery was made by Professor Eske Willerslev from the University of Copenhagen and his international rearch team.

All cells decompose with time. But some cells are better than others to postpone the decomposing and thus delay ageing and eventually death. And there are even organisms that are capable of regenerate and thereby repair damaged cells. These cells – their DNA – are very interesting to the understanding of the process of how cells break down and age.

The research team, which consists of experts in, among other things, DNA-traces in sediments and organisms, have found ancient bacteria that still contains active and living DNA. So far, it is the oldest finding of organisms containing active DNA and thus life on this earth. The discovery was made after excavations of layers of permafrost in the nort-western Canada, the north-eastern Sibiria and Antarctica.

Our project is about eg. examining how bacteria can live after having been frozen down for millions of years. Other researchers has tried to uncover the life of the past and the following evolutionary development by focusing on cells that are in a state of deadlike lethargy. We, on the other hand, have found a method that makes is possible to extract and isolate DNA-traces from cells that are still active. It gives a more precise picture of the past life and the evolution towards the present because we are dealing with cells that still have a metabolistic function – unlike “dead” cells where that function has ceased, says Eske Wilerslev.

After the fieldwork and the isolation of the DNA, the researchers compared the DNA to DNA from a worldwide gene-bank in the US to identify the ancient material. Much in the same way the police compares fingerprints from a crime. The researchers were able to place the DNA more precisely and to place it in a context.

There is a very long way, of course, from our basic research towards understanding why some cells can become that old. But it is interesting in this context to look at how cells break down and are restored and thus are kept over a very long period. Our methods and results can be used to determine if there was ever life on Mars the way we perceive life on earth. And then there is the grand perspective in relation to Darwin’s evolution theory. It predicts that life never returnms to the same genetic level. But our findings allows us to post the question: are we dealing with a circular evolution where development, so to speak, bites its own tail if and when ancient DNA are mixed with new", says Eske Willerslev.

Source: University of Copenhagen

Explore further: New study charts the global invasion of crop pests

add to favorites email to friend print save as pdf

Related Stories

How steroid hormones enable plants to grow

Aug 19, 2014

Plants can adapt extremely quickly to changes in their environment. Hormones, chemical messengers that are activated in direct response to light and temperature stimuli help them achieve this. Plant steroid ...

Chemists uncover powerful new click chemistry reactivity

Aug 14, 2014

Chemists led by Nobel laureate K. Barry Sharpless at The Scripps Research Institute (TSRI) have used his click chemistry to uncover unprecedented, powerful reactivity for making new drugs, diagnostics, plastics, smart materials ...

Recommended for you

New study charts the global invasion of crop pests

8 hours ago

Many of the world's most important crop-producing countries will be fully saturated with pests by the middle of the century if current trends continue, according to a new study led by the University of Exeter.

Zambia lifts ban on safari hunting

9 hours ago

Zambia has lifted a 20-month ban on safari hunting because it has lost too much revenue, but lions and leopards will remain protected, the government said Wednesday.

Wolves susceptible to yawn contagion

13 hours ago

Wolves may be susceptible to yawn contagion, according to a study published August 27, 2014 in the open-access journal PLOS ONE by Teresa Romero from The University of Tokyo, Japan, and colleagues.

User comments : 0