An ancient virus that lay frozen in Siberian permafrost for 48,500 years has become the oldest ever resurrected to date, scientists say.
It is one of seven types of permafrost viruses that have been resurrected after thousands of years.
The youngest was frozen for 27,000 years and the oldest, called Pandoravirus yedoma, has been frozen for 48,500 years.
Although the viruses are not considered a risk to humans, scientists warn that other viruses exposed to melting ice could be “disastrous” and lead to further pandemics.
The 48,500-year-old virus is a pandoravirus, which infects single-celled organisms called amoebas. Image A shows the isolated pandoravirus egg-shaped particle with a small hole or opening called an ostiole (white arrowhead). B shows a mixture of pandoravirus particles and “megavirus” particles with a “stargate” – a white starfish-like structure (white arrowhead)
Pandoravirus yedoma was found in permafrost 16 m below the bottom of a lake in Yukechi Alas in Yakutia, Russia
TYPES OF VIRUSES REVIVED
– Pandora virus
– Pacman virus
“48,500 years is a world record,” said Jean-Michel Claverie, a virologist at the University of Aix-Marseille in France. new scientist.
Named after Pandora’s box, the pandoravirus is a giant virus genus first discovered in 2013, and the second largest in physical size of all known viral genera after the pithovirus.
Pandoravirus is one micrometer long and 0.5 micrometers wide, which means it is visible under a light microscope.
This 48,500-year-old specimen was found in permafrost 16 m below the bottom of a lake in Yukechi Alas in Yakutia, Russia.
Professor Claverie and his colleagues have previously revived two 30,000-year-old permafrost viruses, the first of which was announced in 2014.
All nine viruses are able to infect single-celled organisms called amoebae, but not plants or animals. However, other frozen viruses could be very dangerous to plant and animal life, including humans.
Permafrost is ground that remains permanently frozen even during the summer months. Pictured is melting ice in the Arctic in spring
THAWING PERMAFROST AND GREENHOUSE GASES
Carbon is frozen deep in Arctic permafrost — ground that remains completely frozen at -32°F (0°C) or colder — for at least two consecutive years.
As the Earth warms, scientists fear that some of the carbon in permafrost will escape into the atmosphere as carbon dioxide or methane.
Increasing the amount of these gases in the atmosphere could warm the Earth’s climate even further.
More information: US National Snow and Ice Data Center
About 65% of Russian territory is classified as permafrost – ground that remains permanently frozen even in the summer months.
But, as temperatures rise due to global warming, the ground is now beginning to melt, spewing out animals and objects that have been frozen for thousands of years.
It even spawned an industry dependent on the woolly mammoth – which went extinct around 10,000 years ago – as hunters go in search of unearthed skeletons so they can extract their tusks and sell them to ivory traders. .
But the discovery of such well-preserved specimens has also raised concerns that diseases the animals may have carried were thawed with them and, unlike their hosts, could survive the thaw.
Professor Claverie warned last year of ‘extremely good’ evidence that ‘you can revive bacteria from deep permafrost’.
He even discovered one such virus himself – the pithovirus – which, once thawed from the permafrost, began to attack and kill the amoebae.
While the pithovirus, which had been frozen for some 30,000 years before the experiment, is harmless to humans, Professor Claverie said it demonstrates that long-frozen viruses can ‘wake up’ and start reinfecting the hosts.
Scientists disagree on the exact age of the Arctic ice cap, the permafrost that surrounds it, and therefore the age of the objects it contains.
In the photo, the elongated particle of a pithovirus (1.9 micrometers in length) has a unique cork-like structure at the apex (white arrowhead)
But most of the thawed finds that have been uncovered so far date from the last ice age, around 115,000 to 11,700 years ago.
In their research paper, Professor Claverie and his colleagues argue that the release of live bacteria or archaea that have remained in cryptobiosis in permafrost for millions of years is a potential “public health problem”.
“The situation would be much more dire in the case of plant, animal or human diseases caused by the resurgence of an old, unknown virus,” they say.
“As unfortunately well documented by recent (and ongoing) pandemics, each new virus, even linked to known families, almost always requires the development of very specific medical responses, such as new antivirals or vaccines.”
The Arctic is of course less populated than other parts of the world, but Professor Claverie said more people now travel there to mine resources such as gold and diamonds.
Unfortunately, the first step in exploiting these resources is to remove the upper layers of permafrost, thereby exposing people to viruses.
“How long these viruses might remain infectious once exposed to outdoor conditions (UV light, oxygen, heat) and the likelihood that they will encounter and infect a suitable host in the meantime are still impossible to estimate,” says the crew.
“But the risk is set to increase in the context of global warming as permafrost melting continues to accelerate and more people populate the Arctic as a result of industrial ventures.”
These nine viruses are detailed in more detail in the new preprint document, which has not yet been peer-reviewed, on the bioRxiv waiter.
Last month, scientists warned that the risk of a virus “spreading” to another species increases with the melting of glaciers – slow-moving rivers of ice.
Melting water from glaciers can carry pathogens to new hosts, making parts of the Arctic a “breeding ground for emerging pandemics.”
KILLER VIRUSES COULD BE RELEASED BY ICE FOUNDATION IN ARCTIC, STUDY WARNS
Glaciers melting amid rising global temperatures could be the cause of the next deadly pandemic, a study has found.
Scientists have studied how climate change may affect the risk of “spillover” – a virus jumping to another species – by examining samples from Lake Hazen in the Arctic.
Lake Hazen, seen from above in this NASA image, is the largest High Arctic freshwater lake in the world
They found that the risk of an overflow event increases with melting glaciers, as meltwater can carry pathogens to new hosts.
A warming climate could bring Arctic viruses into contact with new environments and hosts, increasing the risk of this “viral spillover”, experts warn.
“The risk of overtopping increases with runoff from melting glaciers, an indicator of climate change,” the researchers say in their paper, published in Proceedings of the Royal Society B.
“If climate change were to also shift the range of potential vector species and viral reservoirs northward, the High Arctic could become fertile ground for emerging pandemics.”