Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Locked in glaciers, ancient ice may return to life as glaciers melt

07.08.2007
But not too ancient -- DNA deteriorates after 1.1 million years

The DNA of ancient microorganisms, long frozen in glaciers, may return to life as the glaciers melt, according to a paper published online this week in the Proceedings of the National Academy of Sciences by scientists at Rutgers, The State University of New Jersey, and Boston University. The article is scheduled to appear in the print edition on Tuesday, Aug. 14.

The finding is significant, said Kay Bidle, assistant professor of marine and coastal sciences at Rutgers, because scientists didn’t know until now whether such ancient, frozen organisms and their DNA could be revived at all or for how long cells are viable after they’ve been frozen. Bidle is lead author of the article, “Fossil Genes and Microbes in the Oldest Ice on Earth.”

Bidle and his co-authors, Rutgers colleague Paul Falkowski, SangHoon Lee of Korea’s Polar Research Institute and David Marchant of Boston University – melted five samples of ice ranging in age from 100,000 to 8 million years old to find the microorganisms trapped inside.

The researchers wanted to find out how long cells could remain viable and how intact their DNA was in the youngest and oldest ice. “First, we asked, do we detect microorganisms at all"” Bidle said. “And we did – more in the young ice than in the old. We tried to grow them in media, and the young stuff grew really fast. We recovered them [the microorganisms] easily; we could plate them and isolate colonies. They doubled every couple of days.” By contrast, Bidle said, the microorganisms from the oldest ice samples grew very slowly, doubling only every 70 days.

Not only were the microorganisms in oldest ice slow to grow, the researchers were unable to identify them as they grew, because their DNA had deteriorated. In fact, the DNA in the five samples examined showed an “exponential decline” after 1.1 million years, “thereby constraining the geological preservation of microbes in icy environments and the possible exchange of genetic material to the oceans.” “There is still DNA left after 1.1 million years,” Bidle said. “But 1.1 million years is the ‘half-life’ – that is, every 1.1 million years, the DNA gets chopped in half.” Bidle said the average size of DNA in the old ice was 210 base pairs – that is, 210 units strung together. The average genome size of a bacterium, by comparison, is 3 million base pairs.

The researchers chose Antarctic glaciers for their research because the polar regions are subject to more cosmic radiation than the rest of the planet and contain the oldest ice on the planet. “It’s the cosmic radiation that’s blasting the DNA into pieces over geologic time, and most of the organisms can’t repair that damage.” Because the DNA had deteriorated so much in the old ice, the researchers also concluded that life on Earth, however it arose, did not ride in on a comet or other debris from outside the solar system. “…(T)he preservation of microbes and their genes in icy comets may have allowed transfer of genetic material among planets,” they wrote. “However, given the extremely high cosmic radiation flux in space, our results suggest it is highly unlikely that life on Earth could have been seeded by genetic material external to this solar system.”

The five ice samples used in the experiment were taken from two valleys in the Transantarctic Mountains by Marchant, the Boston University glaciologist. “He sent us blocks of ice,” said Bidle of Marchant. “Without them, we couldn’t have done the work. Dave is also one of the few researchers who is knowledgeable about the age of the ice, and also important information about the formation and geology of the ice.”

The actual melting of the ice, growing of microorganisms and examination of DNA was carried out by Bidle and Lee, who was a visiting researcher at Rutgers at the time. Falkowski co-directed the research and helped to write the paper.

Ken Branson | EurekAlert!
Further information:
http://www.rutgers.edu

More articles from Earth Sciences:

nachricht Stagnation in the South Pacific Explains Natural CO2 Fluctuations
23.02.2018 | Carl von Ossietzky-Universität Oldenburg

nachricht First evidence of surprising ocean warming around Galápagos corals
22.02.2018 | University of Arizona

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>