Due to their importance to global primary production and carbon cycles, we are interested in the ecology and molecular biology of viruses that infect phytoplankton, the microscopic plants that fuel almost every aquatic environment. Primarily, we study viruses that infect single-celled eukaryotic algae, but we have also studied viruses that infect other types of organisms.
Our work includes efforts to examine the diversity of algal viruses in freshwater environments and track their distributions and seasonal abundances. As part of this ongoing research we developed quantitative molecular approaches to monitor individual types of algal viruses and observed highly variable abundances among different types of viruses and across seasons and years. However, some viruses seem to have a distinct phenology, or seasonal timing of peak abundance.
genomics & Metagenomics
Building on our success isolating a new algal virus-host system, we recently determined the genome sequence of a Lake Ontario algal virus, a unique giant virus that infects a widespread, common freshwater alga. Through this work we also discovered that this giant dsDNA virus may be host to at least three sub-viral agents, or virophages. We are also conducting metagenomics research to characterize the entire lower food-web (i.e., viruses, bacteria, and protists) of a Lake Ontario harbour.
We have conducted experiments to determine how algal viruses survive in the environment over many seasons, and how viruses influence the mortality of some algal species. We learned that some viruses can remain infectious after overwintering in a frozen pond, and many different types of algal viruses find a refuge in lake sediments where they might persist for many years. We also conducted studies of virus-mediated phytoplankton mortality, and learned that infections of some algal species are ephemeral, but ecologically important events.