Selection of Generalists and Specialists in Viral Quasispecies

by Smith, Sarah D.

Abstract (Summary)
RNA viruses, such as HIV, influenza, and hepatitis viruses, are major sources of human infection and disease. Although vesicular stomatitis virus (VSV) is not a major human pathogen, it serves as an excellent model for RNA virus evolution. In this work, I used VSV to test two predictions of ecological theory that are relevant to speciation. The first prediction is that viruses replicating in homogeneous environments will become specialists as a result of fitness tradeoffs or costs due to differences in fitness landscapes, while viruses that replicate in heterogeneous environments will become generalists. Results show one example of fitness trade-off and two examples of costs associated with fitness landscapes. In contrast to previous works and predictions from ecological theory, results did not show frequent fitness trade-offs. The second prediction is that phenotypic variance in generalist populations will be higher than phenotypic variance in specialist populations. Once again, the prediction was incorrect, and there was no correlation between the history or behavior of a population and it level of variation. However, populations adapting under high-MOI conditions did result in a substantial increase in variance, probably due to the ability of complementation to preserve variation.
Bibliographical Information:


School:University of Toledo Health Science Campus

School Location:USA - Ohio

Source Type:Master's Thesis

Keywords:evolution population genetics vsv variance quasispecies


Date of Publication:01/01/2008

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