Name: Steven Short

Email: steven.short@utoronto.ca

Author: Steve Short

Author affiliation: Department of Biology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON Canada

Abstract title: Transient and Persistent Algal Viruses in a North American Great Lake

Absstract:

To determine if the seasonal dynamics of different phycodnaviruses are similar, quantitative PCR via the 5? nuclease assay was used to monitor several different algal virus genes in Lake Ontario, Canada. Throughout the 13 month study period, the abundances of three putative phycodnavirus polB gene fragments from uncultivated viruses ranged from the detection limit of ca. 5 copies per ml to nearly 10,000 copies per ml. Two of these phycodnavirus gene fragments were detected in nearly every sample, reached their maximum abundances in the autumn, and were lease abundant in spring and summer. The third fragment monitored was detected in only a few samples, but it reached a higher maximum abundance than the other two. To extend this research to cultivated viruses, PCR primers were designed to amplify Chlorovirus polB gene fragments, and sequences identical to Chlorovirus PBCV-CVM1 polB were recovered from Lake Ontario. Quantitative PCR of Lake Ontario CVM1 polB fragments revealed that they, like some uncultivated viruses, persisted throughout the duration of this study; however, their abundance peaked in the late spring and early summer, and was lowest during the autumn and winter months. Together, these results demonstrate that Lake Ontario?s phycodnavirus community is composed of persistent viruses detectable throughout the year, and transient viruses present in only a few sporadic samples. Since persistent algal viruses were able survive in Lake Ontario at remarkably low abundances through several seasons, the results of this study suggest that important questions about phycodnavirus ecology have not yet been answered.