Project: Evolutionary ecology of marine cyanophages

 ABSTRACT

The evolutionary ecology of virus-host interactions are key to understanding viral-induced mortality rates in marine ecosystems, as the pattern and dynamics of virus-host interactions will ultimately determine the influence of viruses on nutrient cycling. Recent studies suggest that the diversity and composition of marine viruses appears to vary over time and space. The goal of this research is to move beyond simply documenting biogeographic patterns in marine viruses and to begin to ask why the genetic composition of marine viruses varies over time and space. Part of the challenge in doing this is that little is known about how the genetic diversity of a marine virus relates to its phenotype. To address this challenge, the PIs are taking an isolation approach, using lytic cyanophages that infect marine Synechococcus as a model system. In this way they can compare the genotype and phenotype of each virus isolate.

There are three specific goals to do this: (1) Identify genetic markers of cyanophage host range (the particular hosts that a phage can infect); (2) Conduct a time-series study of cyanophage isolates from the Pacific and Atlantic coasts of North America; and (3) Using isolates from the time series, characterize cyanophage phenotypes.

Relevant References:

Marston, M., S. Taylor, N. Sme, R. Parsons, T. Noyes, J.B.H. Martiny. "Marine cyanophages exhibit local and regional biogeography," Environmental Microbiology, v.15, 2013, p. 1452.

Clasen J.L.*, C.A. Hanson*, Y. Ibrahim, C. Weihe, M.F. Marston, and J.B.H. Martiny. "Diversity and temporal dynamics of southern California coastal marine cyanophage isolates," Aquatic Microbial Ecology, v.69, 2013, p. 17.

Marston, M.F., F.J. Pierciey, A. Shepard, G. Gearin, J. Qi, C. Yandava, S.C. Schuster, M.R. Henn, J.B.H. Martiny. "Rapid diversification of coevolving marine Synechococcus and a virus," Proceedings of the National Academy of Sciences, v.109, 2012, p. 4544.

Hanson, C.A., J.A. Fuhrman, M.C. Horner-Devine, J.B.H. Martiny. "Beyond biogeographic patterns: processes shaping the microbial landscape," Nature Reviews Microbiology, v.10, 2012, p. 497.