{"id":8305,"date":"2015-04-01T11:29:24","date_gmt":"2015-04-01T11:29:24","guid":{"rendered":"http:\/\/healthmedicinet.com\/news\/the-intraterrestrials-new-viruses-discovered-in-ocean-depths\/"},"modified":"2015-04-01T11:29:24","modified_gmt":"2015-04-01T11:29:24","slug":"the-intraterrestrials-new-viruses-discovered-in-ocean-depths","status":"publish","type":"post","link":"http:\/\/healthmedicinet.com\/news\/the-intraterrestrials-new-viruses-discovered-in-ocean-depths\/","title":{"rendered":"The \u00e2\u20ac\u02dcintraterrestrials’: New viruses discovered in ocean depths"},"content":{"rendered":"

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IMAGE:\u00c2\u00a0<\/strong>The scientists used the deep submergence vehicle Alvin to retrieve sea-floor samples.
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Credit: David Valentine<\/p>\n<\/figcaption>\n<\/p>\n<\/figure>\n

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The intraterrestrials, they might be called.<\/p>\n

Strange creatures live in the deep sea, but few are odder than the viruses that inhabit deep ocean methane seeps and prey on single-celled microorganisms called archaea.<\/p>\n

The least understood of life\u00e2\u20ac\u2122s three primary domains, archaea thrive in the most extreme environments on the planet: near hot ocean rift vents, in acid mine drainage, in the saltiest of evaporation ponds and in petroleum deposits deep underground.<\/p>\n

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Virus in the deep blue sea<\/p>\n

While searching the ocean\u00e2\u20ac\u2122s depths for evidence of viruses, scientists have found a remarkable new one, a virus that seemingly infects archaea that live beneath the ocean floor.<\/p>\n

The researchers were surprised to discover that the virus selectively targets one of its own genes for mutation, and that this capacity is also shared by archaea themselves.<\/p>\n

The findings appear today in a paper in the journal Nature Communications<\/i>.<\/p>\n

The project was supported by a National Science Foundation (NSF) Dimensions of Biodiversity grant to characterize microbial diversity in methane seep ecosystems. Dimensions of Biodiversity is supported by NSF\u00e2\u20ac\u2122s Directorates for Biological Sciences and Geosciences.<\/p>\n

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New information about life in ocean depths<\/p>\n

\u00e2\u20ac\u0153Life far beneath the Earth\u00e2\u20ac\u2122s subsurface is an enigma,\u00e2\u20ac\u009d said Matt Kane, program director in NSF\u00e2\u20ac\u2122s Division of Environmental Biology. \u00e2\u20ac\u0153By probing deep into our planet, these scientists have discovered new information about Earth\u00e2\u20ac\u2122s microbes and how they evolve.\u00e2\u20ac\u009d<\/p>\n

\u00e2\u20ac\u0153Our study uncovers mechanisms by which viruses and archaea can adapt in this hostile environment,\u00e2\u20ac\u009d said David Valentine, a geoscientist at the University of California Santa Barbara (UCSB) and co-author of the paper.<\/p>\n

The results, he said, raise new questions about the evolution and interaction of the microbes that call the planet\u00e2\u20ac\u2122s interior home.<\/p>\n

\u00e2\u20ac\u0153It\u00e2\u20ac\u2122s now thought that there\u00e2\u20ac\u2122s more biomass inside the Earth than anywhere else, just living very slowly in this dark, energy-limited environment,\u00e2\u20ac\u009d said paper co-author Sarah Bagby of UCSB.<\/p>\n

Using the submersible Alvin, Valentine and colleagues collected samples from a deep-ocean methane seep by pushing tubes into the ocean floor and retrieving sediments.<\/p>\n

The contents were brought back to the lab and fed methane gas, helping the methane-eating archaea in the samples to grow.<\/p>\n

When the team assayed the samples for viral infection, they discovered a new virus with a distinctive genetic fingerprint that suggested its likely host was methane-eating archaea.<\/p>\n

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Genetic sequence of new virus holds the key<\/p>\n

The researchers used the genetic sequence of the new virus to chart other occurrences in global databases.<\/p>\n

\u00e2\u20ac\u0153We found a partial genetic match from methane seeps off Norway and California,\u00e2\u20ac\u009d said lead author Blair Paul of UCSB. \u00e2\u20ac\u0153The evidence suggests that this viral type is distributed around the globe in deep ocean methane seeps.\u00e2\u20ac\u009d<\/p>\n

Further investigation revealed another unexpected finding: a small genetic element, known as a diversity-generating retroelement, that accelerates mutation of a specific section of the virus\u00e2\u20ac\u2122s genome.<\/p>\n

Such elements had been previously identified in bacteria and their viruses, but never among archaea or the viruses that infect them.<\/p>\n

\u00e2\u20ac\u0153These researchers have shown that cutting-edge genomic approaches can help us understand how microbes function in remote and poorly known environments such as ocean depths,\u00e2\u20ac\u009d said David Garrison, program director in NSF\u00e2\u20ac\u2122s Division of Ocean Sciences.<\/p>\n

While the self-guided mutation element in the archaea virus resembles known bacterial elements, the researchers found that it has a divergent evolutionary history.<\/p>\n

\u00e2\u20ac\u0153The target of guided mutation\u00e2\u20ac\u201cthe tips of the virus that make first contact when infecting a cell\u00e2\u20ac\u201cis similar,\u00e2\u20ac\u009d said Paul.<\/p>\n

\u00e2\u20ac\u0153But the ability to mutate those tips is an offensive countermeasure against the cell\u00e2\u20ac\u2122s defenses, a move that resembles a molecular arms race.\u00e2\u20ac\u009d<\/p>\n

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Unusual genetic adaptations<\/p>\n

Having found guided mutation in a virus-infecting archaea, the scientists reasoned that archaea themselves might use the same mechanism for genetic adaptation.<\/p>\n

In an exhaustive search, they identified parallel features in the genomes of a subterranean group of archaea known as nanoarchaea.<\/p>\n

Unlike the deep-ocean virus that uses guided mutation to alter a single gene, the nanoarchaea target at least four distinct genes.<\/p>\n

\u00e2\u20ac\u0153It\u00e2\u20ac\u2122s a new record,\u00e2\u20ac\u009d said Bagby.<\/p>\n

\u00e2\u20ac\u0153Bacteria had been observed to target two genes with this mechanism. That may not seem like a huge difference, but targeting four is extraordinary.\u00e2\u20ac\u009d<\/p>\n

According to Valentine, the genetic mutation that fosters these potential variations may be key to the survival of archaea beneath the Earth\u00e2\u20ac\u2122s surface.<\/p>\n

\u00e2\u20ac\u0153The cell is choosing to modify certain proteins,\u00e2\u20ac\u009d he said. \u00e2\u20ac\u0153It\u00e2\u20ac\u2122s doing its own protein engineering. While we don\u00e2\u20ac\u2122t yet know what those proteins are being used for, learning about the process can tell us something about the environment in which these organisms thrive.\u00e2\u20ac\u009d<\/p>\n

###<\/p>\n

Viral DNA sequencing was provided through a Gordon and Betty Moore Foundation grant. The research team also included scientists from the University of California, Los Angeles; the University of California, San Diego; and the U.S. Department of Energy\u00e2\u20ac\u2122s Joint Genome Institute.<\/p>\n

-NSF-<\/p>\n","protected":false},"excerpt":{"rendered":"

IMAGE:\u00c2\u00a0The scientists used the deep submergence vehicle Alvin to retrieve sea-floor samples. view more Credit: David Valentine The intraterrestrials, they might be called. Strange creatures live in the deep sea, but few are odder than the viruses that inhabit deep ocean methane seeps and prey on single-celled microorganisms called archaea. The least understood of life\u00e2\u20ac\u2122s […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-8305","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"http:\/\/healthmedicinet.com\/news\/wp-json\/wp\/v2\/posts\/8305","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/healthmedicinet.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/healthmedicinet.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/healthmedicinet.com\/news\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/healthmedicinet.com\/news\/wp-json\/wp\/v2\/comments?post=8305"}],"version-history":[{"count":0,"href":"http:\/\/healthmedicinet.com\/news\/wp-json\/wp\/v2\/posts\/8305\/revisions"}],"wp:attachment":[{"href":"http:\/\/healthmedicinet.com\/news\/wp-json\/wp\/v2\/media?parent=8305"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/healthmedicinet.com\/news\/wp-json\/wp\/v2\/categories?post=8305"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/healthmedicinet.com\/news\/wp-json\/wp\/v2\/tags?post=8305"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}