DOE Joint Genome Institute

  • COVID-19
  • About Us
  • Contact Us
  • Our Science
    • DOE Mission Areas
    • Science Programs
    • Science Highlights
    • Scientists
    A vertical tree stump outdoors with about a dozen shiitake mushrooms sprouting from its surface.
    Tracing the Evolution of Shiitake Mushrooms
    Understanding Lentinula genomes and their evolution could provide strategies for converting plant waste into sugars for biofuel production. Additionally, these fungi play a role in the global carbon cycle.

    More

    Soil Virus Offers Insight into Maintaining Microorganisms
    Through a collaborative effort, researchers have identified a protein in soil viruses that may promote soil health.

    More

    Data yielded from RIViT-seq increased the number of sigma factor-gene pairs confirmed in Streptomyces coelicolor from 209 to 399. Here, grey arrows denote previously known regulation and red arrows are regulation identified by RIViT-seq; orange nodes mark sigma factors while gray nodes mark other genes. (Otani, H., Mouncey, N.J. Nat Commun 13, 3502 (2022). https://doi.org/10.1038/s41467-022-31191-w)
    Streamlining Regulon Identification in Bacteria
    Regulons are a group of genes that can be turned on or off by the same regulatory protein. RIViT-seq technology could speed up associating transcription factors with their target genes.

    More

  • Our Projects
    • Search JGI Projects
    • DOE Metrics/Statistics
    • Approved User Proposals
    • Legacy Projects
    A panoramic view of a lake reflecting a granite mountain.
    Genome Insider: Methane Makers in Yosemite’s Lakes
    Meet researchers who sampled the microbial communities living in the mountaintop lakes of the Sierra Nevada mountains to see how climate change affects freshwater ecosystems, and how those ecosystems work.

    Listen

    A light green shrub with spiny leaves, up close.
    Genome Insider: A Shrubbier Version of Rubber
    Hear from the consortium working on understanding the guayule plant's genome, which could lead to an improved natural rubber plant.

    Listen

    The switchgrass diversity panel growing at the Kellogg Biological Station in Michigan. (David Lowry)
    Mapping Switchgrass Traits with Common Gardens
    The combination of field data and genetic information has allowed researchers to associate climate adaptations with switchgrass biology.

    More

  • Data & Tools
    • IMG
    • Data Portal
    • MycoCosm
    • PhycoCosm
    • Phytozome
    • GOLD
    iPHoP image (Simon Roux)
    iPHoP: A Matchmaker for Phages and their Hosts
    Building on existing virus-host prediction approaches, a new tool combines and evaluates multiple predictions to reliably match viruses with their archaea and bacteria hosts.

    More

    Abstract image of gold lights and squares against a black backdrop
    Silver Age of GOLD Introduces New Features
    The Genomes OnLine Database makes curated microbiome metadata that follows community standards freely available and enables large-scale comparative genomics analysis initiatives.

    More

    Graphical overview of the RNA Virus MetaTranscriptomes Project. (Courtesy of Simon Roux)
    A Better Way to Find RNA Virus Needles in the Proverbial Database Haystacks
    Researchers combed through more than 5,000 data sets of RNA sequences generated from diverse environmental samples around the world, resulting in a five-fold increase of RNA virus diversity.

    More

  • User Programs
    • Calls for Proposals
    • Special Initiatives & Programs
    • Product Offerings
    • User Support
    • Policies
    • Submit a Proposal
    Green plant matter grows from the top, with the area just beneath the surface also visible as soil, root systems and a fuzzy white substance surrounding them.
    Supercharging SIP in the Fungal Hyphosphere
    Applying high-throughput stable isotope probing to the study of a particular fungi, researchers identified novel interactions between bacteria and the fungi.

    More

    Digital ID card with six headshots reads: Congratulations to our 2022 Function Genomics recipients!
    Final Round of 2022 CSP Functional Genomics Awardees
    Meet the final six researchers whose proposals were selected for the 2022 Community Science Program Functional Genomics call.

    More

    croppe image of the JGI helix sculpture
    Tips for a Winning Community Science Program Proposal
    In the Genome Insider podcast, tips to successfully avail of the JGI's proposal calls, many through the Community Science Program.

    Listen

  • News & Publications
    • News
    • Blog
    • Podcasts
    • Webinars
    • Publications
    • Newsletter
    • Logos and Templates
    • Photos
    2022 JGI-UC Merced interns (Thor Swift/Berkeley Lab)
    Exploring Possibilities: 2022 JGI-UC Merced Interns
    The 2022 UC Merced intern cohort share how their summer internship experiences have influenced their careers in science.

    More

    image from gif that shows where in the globe JGI fungal collaborators are located.
    Using Team Science to Build Communities Around Data
    As the data portals grow and evolve, the research communities further expand around them. But with two projects, communities are forming to generate high quality genomes to benefit researchers.

    More

    Cow Rumen and the Early Days of Metagenomics
    Tracing a cow rumen dataset from the lab to material for a hands-on undergraduate research course at CSU-San Marcos that has since expanded into three other universities.

    More

News & Publications
Home › News Releases › Discovered: Novel Group of Giant Viruses

April 6, 2017

Discovered: Novel Group of Giant Viruses

Giant viruses appear to have evolved from smaller viruses (not from cells) based on presence of nearly complete set of translation-related genes.

Giant virus acquiring genes from different eukaryotic host cells. (Ella Maru studio, http://www.scientific-illustrations.com/)

Depiction of giant virus acquiring genes from different eukaryotic host cells. (Ella Maru studio, http://www.scientific-illustrations.com/)

Viruses have a ubiquitous presence in the world. Their population is estimated to be 1031, 10 times greater than the nonillion (1030) of microbes on the planet—a figure that surpasses the number of stars in the Milky Way. Giant viruses are characterized by disproportionately large genomes and virions that house the viruses’ genetic material. They can encode several genes potentially involved in protein biosynthesis, a unique feature which has led to diverging hypotheses about the origins of these viruses. But after discovering a novel group of giant viruses with a more complete set of translation machinery genes than any other virus known to date, scientists at the U.S. Department of Energy Joint Genome Institute (DOE JGI), a DOE Office of Science User Facility, believe that this group (dubbed “Klosneuviruses”) significantly increases our understanding of viral evolution.

The predicted hosts for the Klosneuviruses are protists – single-celled eukaryotic (nucleus-containing) microorganisms. And while their direct impacts on protists are not yet worked out, these giant viruses are thought to have a significant impact on these protists that help regulate the planet’s biogeochemical cycles. DOE JGI published the findings in the journal Science on April 7, 2017 with collaborators from the National Institutes of Health, University of Vienna, and CalTech.

Frederik Schulz spoke about the team's discovery of the novel group of giant viruses at the DOE JGI 12th Annual Genomics of Energy & Environment Meeting. Watch his talk at http://bit.ly/JGI2017Schulz.

Frederik Schulz spoke about the team’s discovery of the novel group of giant viruses at the DOE JGI 12th Annual Genomics of Energy & Environment Meeting. Watch his talk at http://bit.ly/JGI2017Schulz. Schulz was also interviewed on Science Friday – listen at http://bit.ly/SciFriKlosneuvirus.

“The discovery presents virus evolution for us in new ways, vastly expanding our understanding of how many essential host genes viruses can capture during their evolution,” said National Institutes of Health evolutionary and computational biologist Eugene Koonin, a study co-author whose lab collaborated with DOE JGI on analyzing the Klosneuvirus genome. “Since protein synthesis is one of the most prominent hallmarks of cellular life, it shows that these new viruses are more ‘cell-like’ than any virus anyone has ever seen before.”

Giant Viruses Have a Unique Ability

Scientists have been fascinated by giant viruses since 2003, when a group of French biologists led by Didier Raoult discovered the Mimiviruses. Since then, a handful of other giant virus groups have been found. The unique ability among them to encode proteins involved in translation (typically DNA to RNA to protein) piqued researchers’ interests as to the origin of giant viruses. Since then, two evolutionary hypotheses have emerged. One posits that giant viruses evolved from an ancient cell, perhaps one from an extinct fourth domain of cellular life. Another—a scenario championed by Koonin—presents the idea that giant viruses arose from smaller viruses.

Bubbling nitrifying activated sludge tank at a wastewater treatment plant in Klosterneuburg, Austria. This was the source of the sludge samples used for microcolony sorting. (Marton Palatinszky)

Bubbling nitrifying activated sludge tank at a wastewater treatment plant in Klosterneuburg, Austria. This was the source of the sludge samples used for microcolony sorting. (Marton Palatinszky)

The discovery of Klosneuvirus supports the latter idea, according to Tanja Woyke, DOE JGI Microbial Genomics Program lead and senior author of the paper. “In this scenario, a smaller virus infected different eukaryote hosts and picked up genes encoding translational machinery components from independent sources over long periods of time through piecemeal acquisition,” she said.

At first glance, the suite of “cellular” genes in Klosneuvirus seemed to have a common origin, but when analyzing them in detail, the research team observed they came from different hosts. From the evolutionary trees the team built, they noticed that they were acquired by the viruses bit by bit, at different stages in their evolution. The Klosneuvirus genes contained aminoacyl-tRNA (transfer ribonucleic acid) enzymes with specificity for 19 out of 20 amino acids, along with more than 20 tRNAs and an array of translation factors and tRNA modifying enzymes—an unprecedented finding among all viruses, including the previously known giant viruses.

Taking a New and Unexpected Direction

DOE JGI authors on the Klosneuviruses paper: (left to right) Prokaryote Super Program Head Nikos Kyrpides; Functional Annotation Group Head Natalia Ivanova; study senior author and Microbial Genomics Program Head Tanja Woyke; and, study first author Frederik Schulz.

DOE JGI authors on the Klosneuviruses paper: (left to right) Prokaryote Super Program Head Nikos Kyrpides; Functional Annotation Group Head Natalia Ivanova; study senior author and Microbial Genomics Program Head Tanja Woyke; and, study first author Frederik Schulz.

JGI postdoctoral researcher Frederik Schulz and Woyke unearthed Klosneuvirus while analyzing microcolony sequence data from a wastewater treatment plant sample in Klosterneuburg, Austria. This data was generated under a DOE JGI Community Science Program (CSP) project focused on the diversity of nitrifying bacteria for converting ammonia to nitrate in industrial and sewage waste treatment. “We expected genome sequences of nitrifying bacteria in the microcolony sequence data,” Woyke said. “Finding a giant virus genome took the project into a completely new and unexpected, yet very exciting direction.”

When Schulz, the study’s first author, noticed that several of the metagenomes were viral in origin, he and Woyke conducted analyses to determine their source. They found that the Klosneuvirus group came from a novel viral lineage affiliated with Mimiviruses.

“Mining sequence data in DOE JGI’s Integrated Microbial Genomes & Microbiomes (IMG/M) system, which houses thousands of metagenomes, allowed us to find evolutionary relatives of our Klosneuvirus,” Schulz said. He notes that while the metagenomic discovery of Klosneuviruses helped answer important evolutionary questions, the actual biological function of the translation system genes remains elusive—at least until these viruses are grown in the laboratory together with their hosts.

And Koonin believes there are more giant viruses waiting to be discovered in metagenomic data.  “I’m quite confident that the current record of the genome size of giant viruses will be broken,” he says. “We are going to see the real Goliaths of the giant virus world.”

 

Share this:

  • Click to share on Facebook (Opens in new window)
  • Click to share on LinkedIn (Opens in new window)
  • Click to share on Pinterest (Opens in new window)
  • Click to share on Twitter (Opens in new window)
  • Click to print (Opens in new window)

The U.S. Department of Energy Joint Genome Institute, a DOE Office of Science User Facility at Lawrence Berkeley National Laboratory, is committed to advancing genomics in support of DOE missions related to clean energy generation and environmental characterization and cleanup. JGI provides integrated high-throughput sequencing and computational analysis that enable systems-based scientific approaches to these challenges. Follow @jgi on Twitter.

DOE’s Office of Science is the largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

Filed Under: News Releases

More topics:

  • COVID-19 Status
  • News
  • Science Highlights
  • Blog
  • Webinars
  • CSP Plans
  • Featured Profiles

Related Content:

You can move, but you can’t hide

Illustration of a magnifying glass identifying viruses and plasmids.

JGI announces second round of 2023 New Investigator awardees

From left to right: [above] Emma Bell, Mallory Choudoir, Sneha Couvillion, Tobin Hammer, Christina Hazard, Rachel Mackelprang, Brook Moyers, Mei, Ran,; [below] Benjamin Peterson, Dacheng Ren, Allison Rober, Neal Scott, Chikae Tatsumi, Vojtech Tlaskal, Fernando Torralbo, Luis Felipe Valdez-Nuñez

A Collaboration to Improve Plant Genome Annotations Across Species

A tiled collage of square photos of different plants - soybeans, and sorghum, for example.

From Berkeley to Binghamton: Tracking Strawberry Evolution

iPHoP: A Matchmaker for Phages and their Hosts

iPHoP image (Simon Roux)

Supercharging SIP in the Fungal Hyphosphere

Green plant matter grows from the top, with the area just beneath the surface also visible as soil, root systems and a fuzzy white substance surrounding them.
  • Careers
  • Contact Us
  • Events
  • User Meeting
  • MGM Workshops
  • Internal
  • Disclaimer
  • Credits
  • Policies
  • Emergency Info
  • Accessibility / Section 508 Statement
  • Flickr
  • LinkedIn
  • RSS
  • Twitter
  • YouTube
Lawrence Berkeley National Lab Biosciences Area
A project of the US Department of Energy, Office of Science

JGI is a DOE Office of Science User Facility managed by Lawrence Berkeley National Laboratory

© 1997-2023 The Regents of the University of California