New viral way of life discovered in deep-sea vents

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Deep-sea hydrothermal vents look like alien worlds, their landscapes and fauna unlike any on Earth. Now a new study suggests that life works differently there too. While studying the viruses that inhabit the scalding waters surrounding a vent in the Western Pacific, Eric Wommack noticed that a large proportion turned out to be docile tenants that lurk inside their bacterial hosts without causing much trouble.

Deep-sea hydrothermal vents look like alien worlds, their landscapes and fauna unlike any on Earth. Now a new study suggests that life works differently there too.

While studying the viruses that inhabit the scalding waters surrounding a vent in the Western Pacific, Eric Wommack noticed that a large proportion turned out to be docile tenants that lurk inside their bacterial hosts without causing much trouble. Marine phages - the viruses that parasitise bacteria and archaea in the sea - tend to infect their hosts, divide and burst them like balloons.

"We've never see that before anywhere else we've looked in the ocean," says Wommack, a microbiologist at the University of Delaware in Newark, who built a device that sinks to the ocean floor and, with the help of a remote submarine, ferries 120-litre samples of water to a waiting boat.

Instead of hijacking bacteria to spawn offspring, these cell-splitting - or lysogenic - viruses insert their short genomes into the bacteria's own, endowing it with potentially useful genes.

Survival genes

"Maybe the viruses that these bacteria are harbouring have genes that are aiding the bacteria in surviving in this harsh environment," Wommack says.

During times of stress, the phages awake and churn out copies of themselves. During this awakening, viruses can mistakenly encapsulate bacterial genes and pass them onto new microbes.

Article continues on New Scientist