Ancient virus buried in Siberian permafrost for 48,500 years resurfaces

by NewsTimeOffice

An ancient virus frozen in Siberian permafrost for 48,500 years has become the oldest virus ever revived, scientists say.

It is among seven types of permafrost viruses that have resurfaced after thousands of years.

The youngest has been frozen for 27,000 years, and the oldest, called Pandoravirus edoma, has been frozen for 48,500 years.

Although the viruses are not considered a risk to humans, scientists have warned that other viruses released by melting ice could be ‘catastrophic’ and lead to new pandemics.

The 48,500-year-old virus is a pandoravirus, which infects single-celled organisms known as amoebas. Figure A shows isolated egg-shaped particles of Pandoravirus 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 52 feet (16 m) below a lake in Yukechi Alas, Yakutia, Russia.

Regenerative virus type

– Pandoravirus

– Cedratvirus

– Megavirus

– Pacmanvirus

– Pithovirus

‘48,500 years is a world record,’ Jean-Michel Clavery, a virologist at the University of Aix-Marseille in France, told New Scientist.

Named after Pandora’s Box, Pandoraviruses are a genus of giant viruses first discovered in 2013 and are the second largest in physical size of any known viral genus after Pithovirus.

Pandoravirus is 0.5 of a micrometer long and 0.5 of a micrometer wide, meaning it is visible with a light microscope.

This particular 48,500-year-old specimen was found in permafrost 52 feet (16 m) below a lake in Yukechi Alas, Yakutia, Russia.

Professor Clavery and his colleagues previously recovered two 30,000-year-old viruses from permafrost, the first of which was announced in 2014.

All nine viruses are capable of infecting single-celled organisms known as amoebae – but not plants or animals. However, other freezing viruses can be very dangerous to plant and animal life, including humans.

Permafrost is ground that remains permanently frozen even during the summer months. Pictured, Arctic ice melts in spring

Melting permafrost and greenhouse gases

Carbon is frozen deep in Arctic permafrost—ground that is completely frozen at -32°F (0°C) or colder—for at least two years.

As the world warms, scientists worry that some of the carbon in the permafrost may escape into the atmosphere as carbon dioxide or methane.

Increasing the amount of these gases in the atmosphere could make the Earth’s climate even warmer.

More information: US National Snow and Ice Data Center

About 65 percent of Russian territory is classified as permafrost – ground that remains permanently frozen even during the summer months.

But, as temperatures rise due to global warming, the ground is now thawing, coughing up animals and objects frozen for thousands of years.

The remains of a woolly rhinoceros that went extinct about 14,000 years ago and the head of a 40,000-year-old wolf – which perfectly still had fur – have been discovered in recent years.

It has even given rise to an industry dependent on the woolly mammoth – which went extinct around 10,000 years ago – as poachers seek out the skeletons they find so they can extract their tusks and sell them to ivory traders.

But the discovery of such well-preserved specimens has given rise to fears that the diseases the animals carried may have coagulated with them and, unlike their hosts, survived being thawed.

Professor Clavery warned last year of ‘very good’ evidence that ‘you can revive bacteria from deep permafrost’.

He even discovered one such virus himself – Pithovirus – which began to attack and kill amoebas when thawed from permafrost.

Although Pithovirus, which had been frozen for around 30,000 years before the experiment, is not harmful to humans, Professor Clavery said it showed that long-frozen viruses can ‘awaken’ and start re-infecting hosts.

Scientists disagree about the exact age of the Arctic ice cap, the permafrost that surrounds it, and therefore the age of the objects it contains.

Illustrated, elongated particles (1.9 micrometers in length) of a pithovirus exhibit a single apex cork-like structure (white arrowhead).

But most of the defrosted finds uncovered so far date from the last ice age, about 115,000 to 11,700 years ago.

In their paper, Professor Clavery and colleagues say the release of live bacteria or archaea that have remained in cryptobiosis in permafrost for millions of years is a potential ‘public health concern’.

‘The resurgence of an ancient unknown virus will make the situation even more catastrophic in terms of plant, animal or human disease,’ they say.

‘Unfortunately as well documented by recent (and ongoing) epidemics, each new virus, even those belonging to known families, almost always requires the development of highly specific treatment responses such as new antivirals or vaccines.’

The Arctic is certainly less populated than other parts of the world, but Professor Clavery says more people are now moving there to mine resources such as gold and diamonds.

Unfortunately, the first step in mining these resources is removing the top layers of permafrost, thus exposing humans to the virus.

‘It is still impossible to predict how long these viruses can remain infectious once exposed to external conditions (UV light, oxygen, heat) and the probability of encountering and infecting a suitable host in the interval,’ the team says.

‘But the risk is bound to increase in the context of global warming as permafrost melting continues to accelerate, and more people populate the Arctic in the face of industrial enterprise.’

These nine viruses are described in more detail in the new preprint paper, yet to be peer-reviewed on the BioArxive server.

Last month, scientists warned that as glaciers melt, there is an increased chance of the virus being ‘spilled’ into other species – rivers of slow ice.

Meltwater from glaciers can transport pathogens to new hosts, making the Arctic a potential ‘fertile ground for fertility epidemics’.

Melting Arctic ice could release killer viruses, study warns

Glaciers that are melting amid rising global temperatures could be the cause of the next deadly pandemic, a study says.

Scientists investigated how climate change could affect the risk of ‘spillover’ – a virus jumping into another species – by examining samples from Lake Hazen in the Arctic.

Lake Hazen, the world’s largest high Arctic freshwater lake, is seen from above in this NASA image

They found that the likelihood of a spillover event increases with melting glaciers, as meltwater can transport pathogens to new hosts.

A warmer climate could expose Arctic viruses to new environments and hosts, increasing the risk of ‘viral spillover’, experts warn.

“Glacier meltwater increases the risk of spillover, a proxy for climate change,” the researchers said in their paper published in the Proceedings of the Royal Society B.

‘If climate change shifts the range of potential viral vectors and reservoir species northwards, the High Arctic could become fertile ground for emerging epidemics.’

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