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.
