Abstracts (first author)
Genetic robustness and environmental robustness in an RNA virus
Robustness, the ability of phenotypes to withstand perturbation, is often categorized into environmental robustness, resistance to environmental change, and genetic robustness, resistance to mutation. Determining how robustness interacts with the fitness landscape is vital to increasing our understanding of how organisms successfully adapt to changing environments. Studies in proteins and RNA molecules have shown that areas of the fitness landscape with high environmental robustness have high genetic robustness, a property that has been termed plastogenetic congruence. However, it is unknown how environmental and genetic robustness relate at higher levels of biological organization such as organisms. We have experimentally evolved an RNA virus, ϕ6, to have higher resistance to heat shock, a form of environmental robustness. We have tested the virus for genetic robustness using a mutagen and shown that the evolved virus maintained higher fitness and therefore had higher genetic robustness. Previous work with this virus has shown that increased genetic robustness does not necessarily lead to increased environmental robustness. Our investigations of the mutations leading to increased robustness allow us to suggest a mechanism linking environmental and genetic robustness in an RNA virus. The study of robustness at the level of a virus provides insight into the nature of the fitness landscape and may help predict evolutionary trajectories.