Researchers capture first representative of most abundant giant viruses in the sea

March 29, 2018, University of British Columbia

Christoph Deeg and Curtis Suttle isolated Bodo saltans virus in samples from UBC's Nitobe Memorial Garden. Credit: University of British Columbia
Bodo saltans virus, the first isolated representative of the most abundant giant viruses in the sea, has been unveiled by researchers at the University of British Columbia.

The , whose weighs in at 1.39 million bases of DNA, is one of the largest ever isolated, and the largest known to infect zooplankton.

"Bodo saltans virus is one of the few giants we've characterized that infects a common and ecologically important ," says University of British Columbia researcher Curtis Suttle. "It's representative of the most abundant giant viruses in the sea, yet until BsV was discovered, there was no way to investigate these viruses in the lab."

Because Bodo saltans virus (BsV) has to compete with a multitude of other viruses to infect its plentiful host-a microzooplankton called Bodo saltans-it comes armed to the hilt. It possesses an arsenal of toxins and DNA cutting enzymes, which likely interfere with other viruses trying to replicate inside the host.

During infection, BsV maneuvers towards the rear of the host cell and releases its . It appears that as BsV evolved it stole genetic machinery from the host to help in the infection process.

BsV doesn't carry transfer RNA (tRNA), part of the replication machinery all other giant viruses carry. It does, however, carry tRNA repair genes, making it likely that the virus uses the host's own tRNA during infection. Again, these genes appear to have been coopted by the virus directly from the host.

Cell of Bodo saltan 24 hours after BsV infection (Left) and BsV virion assembly and maturation (Right). Credit: Christoph Deeg, Curtis Suttle, University of British Columbia.

More than 10 per cent of BsV's genome encodes the same group of proteins that are likely involved in combating the host's antiviral system.

"These genes are actively being duplicated in an accordion-like mechanism in the periphery of the viral genome," says UBC graduate student Christoph Deeg, first author on the paper. "This suggests that the virus is engaged in an evolutionary arms race with its host, and could offer on explanation of how the genomes of giant viruses could reach their impressive complexity."

Giant viruses have much more DNA than typical viruses, enabling them to produce a multitude of proteins that allows them to replicate largely independently of their host.

Although researchers knew BsV-like viruses existed based on sequenced environmental DNA, only now has a representative virus been captured and studied in the lab. The Bodo saltans virus was isolated in samples from UBC's Nitobe Memorial Garden.

The researchers describe it in eLife.

Explore further: Newly discovered giant viruses have 'the most complete translational apparatus of known virosphere'

More information: Christoph M Deeg et al, The kinetoplastid-infecting Bodo saltans virus (BsV), a window into the most abundant giant viruses in the sea, eLife (2018). DOI: 10.7554/eLife.33014

Related Stories

Giant virus found in marine predatory plankton

November 2, 2010

Researchers have identified a marine giant virus that infects Cafeteria roenbergensis, a widespread planktonic predator that occupies a key position in marine food webs, according to a study.

How viruses hijack a host's energy supply

June 6, 2017

Viruses occupy a strange no-man's-land between the living and the nonliving. In order to reproduce, they must infect a living host and hijack its resources. But while it is understood that this parasitic relationship can ...

Recommended for you

After a reset, Сuriosity is operating normally

February 23, 2019

NASA's Curiosity rover is busy making new discoveries on Mars. The rover has been climbing Mount Sharp since 2014 and recently reached a clay region that may offer new clues about the ancient Martian environment's potential ...

Study: With Twitter, race of the messenger matters

February 23, 2019

When NFL player Colin Kaepernick took a knee during the national anthem to protest police brutality and racial injustice, the ensuing debate took traditional and social media by storm. University of Kansas researchers have ...

Solving the jet/cocoon riddle of a gravitational wave event

February 22, 2019

An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

betterexists
not rated yet Mar 29, 2018
Make a Dilute solution of homogenate of a collection of such viruses (has to be pure); Then Inject bit by bit into the cells of host zooplankton to observe for production of any Anti-Viral Particles; Collect them and later on check out the entire process thoroughly !
rrwillsj
1 / 5 (1) Mar 29, 2018
be, Can you promise (pinkie-ring swear) that your experiments will not result in stronger, more resilient viruses?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.