In what sounds like something straight out of a science fiction movie, scientists have revived a virus believed to have remained frozen in the Siberian permafrost for 30,000 years. What's more, it's still infectious.
Though not transmittable to humans, the virus calls up the possibility of other viruses that could be lurking in the ice that, if released, could be harmful to people.
This electron microscope image provided by researchers in March 2014 shows a section of a Pithovirus particle, dark outline, inside an infected Acanthamoeba castellanii cell. The length of the particle is about 1.5 microns with a 0.5 micron diameter. Researchers have revived the virus, which is more than 30,000 years old, after finding it in the permafrost of northeast Siberia. While it poses no threat to people, its recovery suggests that dangerous germs might emerge in the future as permafrost thaws because of global warming or mineral exploration, researchers suggested Monday, March 3, 2014 in the Proceedings of the National Academy of Sciences. (AP/IGS, CNRS-AMU, Julia Bartoli, Chantal Abergel)
"There's good reason to think there could be pathogenic viruses in there too," team co-leader Chantal Abergel with France's Aix-Marseille University told the New Scientist.
The virus, named Pithovirus sibericum by the French team, is unusually large by virus standards, measuring about the size of a small bacterium at 1.5 micrometers long, Nature Communications reported. It is infectious to unicellular protists, like amoebae.
The virus, seen as the dark oblong shapes, inside an infected amoeba. (Image source: YouTube)
"The revival of such an ancestral amoeba-infecting virus used as a safe indicator of the possible presence of pathogenic DNA viruses, suggests that the thawing of permafrost either from global warming or industrial exploitation of circumpolar regions might not be exempt from future threats to human or animal health," the study's abstract, published in the Proceedings of the National Academy of Sciences, stated.
Though the study team said mining or thawing in arctic areas could, in theory, impact human health, virologist Curtis Suttle with the University of British Columbia in Canada, who was not involved in this research, told Nature this idea "stretches scientific rationality to the breaking point."
Either way, Buford Price with the University of California-Berkeley said "revival of any kind of ancient virus is always newsworthy," New Scientist reported.
Watch the researcher's video showing the virus as it infects an amoeba:
Overall, Pithovius sibericum is different than other previously identified giant viruses in how it spreads, its proteins and its smaller genome.
“That huge particle is basically empty,” biologist Jean-Michel Claverie told Nature. "We thought it was a property of viruses that they pack DNA extremely tightly into the smallest particle possible, but this guy is 150 times less compacted than any bacteriophage. We don’t understand anything anymore!"