A link for unrelated viruses

Apparently unrelated viruses that infect all three domains of life—Archaea, Bacteria, and Eukarya—could share a common ancestry, according to a report by an international team of scientists in the December 3 Molecular Cell.

So far, researchers believe they have uncovered two lineages that infect all domains, with another virus line infecting two. In the Molecular Cell study, senior author Roger Burnett, of the Wistar Institute in Philadelphia, and colleagues have now shown through molecular modeling that many of these viruses' coat protein sequences are compatible with the major coat protein of bacteriophage PRD1. That builds on earlier evidence that a number of viruses are descended from that bacteriophage. "This new experimental evidence supporting the proposed PRD1-adenovirus lineage places the idea on a much firmer footing," Burnett told The Scientist.

Viruses were often viewed and studied as unrelated families until 5 years ago, when Burnett's lab and colleagues...