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

March 28, 2018

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 virus, whose genome weighs in at 1.39 million bases of DNA, is one of the largest giant viruses 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 host," 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 viral genome. 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.

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.

The kinetoplastid-infecting Bodo saltans virus (BsV), a window into the most abundant giant viruses in the sea

https://elifesciences.org/articles/33014
-end-


University of British Columbia

Related DNA Articles from Brightsurf:

A new twist on DNA origami
A team* of scientists from ASU and Shanghai Jiao Tong University (SJTU) led by Hao Yan, ASU's Milton Glick Professor in the School of Molecular Sciences, and director of the ASU Biodesign Institute's Center for Molecular Design and Biomimetics, has just announced the creation of a new type of meta-DNA structures that will open up the fields of optoelectronics (including information storage and encryption) as well as synthetic biology.

Solving a DNA mystery
''A watched pot never boils,'' as the saying goes, but that was not the case for UC Santa Barbara researchers watching a ''pot'' of liquids formed from DNA.

Junk DNA might be really, really useful for biocomputing
When you don't understand how things work, it's not unusual to think of them as just plain old junk.

Designing DNA from scratch: Engineering the functions of micrometer-sized DNA droplets
Scientists at Tokyo Institute of Technology (Tokyo Tech) have constructed ''DNA droplets'' comprising designed DNA nanostructures.

Does DNA in the water tell us how many fish are there?
Researchers have developed a new non-invasive method to count individual fish by measuring the concentration of environmental DNA in the water, which could be applied for quantitative monitoring of aquatic ecosystems.

Zigzag DNA
How the cell organizes DNA into tightly packed chromosomes. Nature publication by Delft University of Technology and EMBL Heidelberg.

Scientists now know what DNA's chaperone looks like
Researchers have discovered the structure of the FACT protein -- a mysterious protein central to the functioning of DNA.

DNA is like everything else: it's not what you have, but how you use it
A new paradigm for reading out genetic information in DNA is described by Dr.

A new spin on DNA
For decades, researchers have chased ways to study biological machines.

From face to DNA: New method aims to improve match between DNA sample and face database
Predicting what someone's face looks like based on a DNA sample remains a hard nut to crack for science.

Read More: DNA News and DNA Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.