Scientists discovered something huge, literally, in the virus world:
viruses so big they could be seen with a standard microscope. These
massive parasites were considered rare at the time, but they�??ve since
proved more common than anyone expected. Now, researchers have found
entire giant virus genomes embedded in the genomes of several common
algae. The find suggests this strange viral group is even more
prolific�??and potentially influential�??than scientists thought.

At Virginia Polytechnic Institute and State University, microbiologist
Frank Aylward and his postdoc Mohammad Moniruzzaman followed up on this
mystery by matching genes found in giant virus DNA to those previously
documented in other genomes. Viral matches �??kept popping up in algal
genomes,�?� Aylward recalls. So the duo and their colleagues
systematically looked through genomes representing all of the sequenced
DNA from the group of algae called Chlorophytes.An entire giant virus
was genetically present
[www.nature.com] the DNA of a dozen
of these species.

In all, the viruses added between 78 and 1782 genes to the algae. Two
algae even had the whole genomes of two giant viruses in their DNA, in
one case making up 10% of the algae�??s total gene count.

Giant virus genomes discovered lurking in DNA of common algae | Science
| AAAS (sciencemag.org)
[www.sciencemag.org]