Ancient viruses regenerated from 700-year-old frozen reindeer poop

Date: Oct-29-2014 Reindeer poop preserved for 700 years in a subarctic ice patch in northern

Canada has yielded sufficiently well-preserved remnants of two ancient viruses that

scientists have managed to regenerate using modern, molecular genetics.

The team recreated the code of a complete DNA and one partial RNA viral genome from 700-year-old caribou feces.

Viruses preserved in ancient samples provide valuable information about viral diversity from long ago; they help us trace how today's species evolved and study their

biology.

However, it is not easy to recreate ancient viruses. Even when they are preserved

in ancient specimens, they are somewhat degraded and their concentrations are

low.

Now, a new study led by the University of California, San Francisco (UCSF), shows

how it is possible, using modern techniques in the field of molecular genetics, to

recreate ancient viruses from cryogenically preserved materials.

Senior author Eric Delwart, an Adjunct Professor in UCSF's Department of

Laboratory Medicine, and colleagues report their findings in the Proceedings of

the National Academy of Sciences.

The team resurrected two ancient viruses and showed one could infect a plant

The method the team used to resurrect the ancient viruses is called "viral

particle-associated nucleic acid enrichment."

In their paper, they describe how using this approach they recreated the code of a

complete DNA and one partial RNA viral genome from 700-year-old caribou feces

recovered from a subarctic ice patch in the Selwyn mountains of the Yukon and

Northern Territories, in Canada.

The authors write:

"We were able to recover and characterize two viruses in replicated experiments

performed in two different laboratories: a small circular DNA viral genome (ancient

caribou feces associated virus, or aCFV) and a partial RNA viral genome (Ancient

Northwest Territories cripavirus, or aNCV)."

Then using "reverse genetics," they reconstituted one of the viruses and showed it

was able to spread and reproduce in a living plant.

The team says their findings show that under frozen conditions, "encapsidated

viral nucleic acids" can survive for centuries, providing enough material to allow

"molecular genetics to regenerate viruses to study their biology."

Will global warming resurrect old, infectious viruses?

The study findings raise the question of whether dormant, potentially infectious

pathogens will emerge if global warming melts enough ice and permafrost. What might

the consequences be for people and wildlife?

Prof. Delwart says there is a theoretical risk of this: "the nucleic acid of the

virus was in great shape in our sample," he notes in a report on the study by New

Scientist.

"But old viruses could only re-emerge if they have significant advantages over the

countless perfect viruses we have at present," he adds.

In February 2014, Medical News Today learned of another study that

discovered antibiotic resistance genes in viruses

found in 700-year-old human feces.

Written by Catharine Paddock PhD

Not to be reproduced without permission.

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Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.