Experimental ecology of a viral host range expansion.
Dennehy, John1, Friedenberg, Nicholas*,2, Turner, Paul1, Holt, Robert3, 1 Department of Ecology and Evolutionary Biology, New Haven, CT, USA2 Department of Biology, Hanover, NH, USA3 Department of Zoology, Gainesville, FL
ABSTRACT- The emergence if viruses on new hosts can have widespread ecological, social, and economic consequences. Using experimentally-derived estimates of density dependent growth on a native and novel host, we predict the effect of transmission rate on the sustainability of an emerging RNA virus, the bacteriophage phi-6h infecting two species of Pseudomonas in coarse-grained environments. Our test of these predictions with serial passage experiments reveals a range of transmission rates over which the native host is a source while the novel host is a sink. We also find that periodic exposure to the native host rescues emerging phage populations in this critical range of transmission rates. Our experiments demonstrate that the fitness of a virus in a novel host population is a product of fitness at two scales: within-host growth and between-host transmission. The temporal and spatial availability of host species can therefore determine the timing and success of an emerging virus.
Key words: disease ecology, niche evolution, range expansion, density dependence
All materials copyright The Ecological Society of America (ESA), and may not be used without written permission.