A careful examination of frozen caribou poop has turned up
two never-before-seen viruses.
The viruses are hundreds of years old: One of them probably
infected plants the caribous ate. The other may have infected insects that
buzzed around the animals.
The findings prove viruses can survive for surprisingly long
periods of time in a cold environment, according to Eric Delwart, a researcher
at Blood Systems Research Institute in San Francisco.
"The DNA of viruses is preserved extremely well under
cold conditions," he says.
Delwart's day job at Blood Systems is to find new viruses
that could contaminate the blood supply. But he enjoys looking in odd places
too. He got interested in ice cores from high mountain regions, after reading
about all the interesting old things the ice contained.
"Things like old shoes and arrowheads," he says,
"and then I realized this is nature's freezer, which should also contain
organic remains."
Delwart had one particular type of organic remains in mind:
caribou poop. Just about everything an animal eats can be infected with a
virus. And that makes animals, including humans, virus vacuums that suck up
every virus in their path.
"I mean we're constantly shoving viruses down our
throat and if you look at poo samples from humans and from animals you will
find a lot of viruses," he says.
Caribous hang out on ice, so these pristine ice cores are
actually full of poo. And as scientists go through layer after layer of ice,
the poo gets older and older.
Delwart examined poop from northern Canada that was 700
years old. The result, published Monday in the Proceedings of the National
Academy of Sciences, is the discovery of these two viruses. npr
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