MAY 09, 2018 11:25 AM PDT

A Giant Ocean Virus has Been Isolated & Characterized

WRITTEN BY: Carmen Leitch

We share the world with millions of microbes; one study estimated that there are no fewer than 320,000 microorganisms that have the potential to infect mammals. The ocean is one place that many viruses call home. Now scientists at the University of British Columbia have characterized one of the giant viruses commonly found in the sea, Bodo saltans virus (BsV). 

Christoph Deeg and Curtis Suttle isolated Bodo saltans virus in samples from UBC's Nitobe Memorial Garden. / Credit: University of British Columbia

The BsV has a massive genome with 1.39 million nucleotide bases, making it one of the biggest viruses ever isolated. It is now the largest known to infect zooplankton, and has been reported in eLife

All the DNA these giant viruses carry enables them to create proteins without a host, unlike most viruses we are familiar with. Typically, viruses are thought of as hijackers that take over the cellular machinery of a host and use the stuff for its own purposes. These giant viruses don’t need to do that.

BsV can infect a microzooplankton named Bodo saltans. To do so, it must outcompete other viruses. It has an arsenal on hand, including enzymes that chop up DNA, and toxins.

This is a 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

"Bodo saltans virus is one of the few giants we've characterized that infects a common and ecologically important host," noted 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."

When BsV infects its host, it releases its viral genome in the rear of the host cell. It seems that as it evolved, it grabbed some parts of its host’s genome. For example, BsV does not have tRNA molecules, but it carries tRNA repair genes. Around ten percent of its genome codes for the same class of proteins that probably fight the host immune system.

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

Suttle talks a bit more about his research and what it means for us in this short video.

Sources: AAAS/Eurekalert! Via University of British Columbia, mBio, eLife

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
JUL 17, 2018
Videos
JUL 17, 2018
Novartis Ends Antibiotic Research
The United Nations has warned that by 2050, antibiotic-resistant microbes might kill ten million people every year....
AUG 05, 2018
Microbiology
AUG 05, 2018
The War Beneath Our Feet
The bacteria living in the soils of Earth seem locked in battle with the fungi there....
AUG 29, 2018
Health & Medicine
AUG 29, 2018
Wearing Contacts While Sleeping Can Lead to Severe Eye Infections
Contact lenses can be a boon to patients who need eyesight correction. Fumbling with glasses, changing to sunglasses when outside, and trying to exercise o...
SEP 18, 2018
Microbiology
SEP 18, 2018
The Earliest Influences on the Microbiome Have a Lasting Impact
We coexist with microorganisms, and many of them play an important role in our health....
SEP 20, 2018
Videos
SEP 20, 2018
The Lowdown on Vaccine Development and Production
Learn more about how vaccines are developed and tested, from the CDC....
SEP 27, 2018
Microbiology
SEP 27, 2018
How Bacterial Cells Take out the Trash
Some types of bacteria create tiny versions of themselves that cannot reproduce - miniature spheres lacking chromosomal DNA that are known as minicells....
Loading Comments...