A Changing View of Viruses in the Evolution and Ecology of Life
When: October 26, 2009 11AM PDT
Viruses are the most abundant life-like entities on the planet. Studies over the past twenty years by environmental virologists have significantly changed our view of the role of viruses in the biosphere. It is becoming increasingly likely that viruses or virus-like entities are major players in earth’s early life and in the present day ecology and evolution of life.
We are interested in the isolation and molecular characterization of archaeal viruses from high temperature environments. High temperature (>80C) acidic environments (pH<3.0) have proven to be a rich source of viruses replicating in crenarchaeal hosts (viruses replicating in host from the domain Archaea). We have isolated and characterized a number of these unusual viruses. Using both culture-dependent and culture-independent approaches, a broad diversity of virus particle morphologies and genome compositions have been detected. Like most crenarchaeal viruses isolated to date, the viral open reading frames (ORFs) have little to no similarity to proteins in the public databases. However, despite this lack of homology, these viruses have particle structures reminiscent of viruses of Eukarya and Bacteria, suggesting an evolutionary relationship between viruses from all domains of life.