Presentation Detail

Mutation

Bhardwaj, Anand [1], Cutler, David [2], Real, Leslie [3].

Mutation Accumulation and the Rate of Adaptation in Viruses.

Viruses, and RNA viruses in particular, have extremely high mutation rates. This, combined with their rapid rates of reproduction allow them to evolve at ecological timescales. However, the processes that influence and ultimately limit their rate of evolution are still poorly understood.The dynamics of intra-cellular replication of single stranded viruses have a major effect on patterns of mutation accumulation, and as a consequence, on the ability of these viral populations to evolve and to avoid extinction.A majority of models of viral evolution assume constant population size and equilibrium dynamics. We relax these assumptions in order to model the effects of intra-cellular replication strategies- from the "stamping machine" mode of viral replication in which mutations accumulate linearly, to the "binary" mode of viral replication in which mutations accumulate exponentially- on mutation accumulation.Our conclusions on the sensitivity of viral populations to demographic extinction through processes like chemically-induced lethal mutagenesis differ from those drawn from equilibrium models, suggesting these supposedly "evolution-proof" anti-viral control strategies could be more broadly applicable than previously thought. The dynamics of adaptive evolution are also affected by the mode of replication, where low copy-number replication events like the formation of opposite-sense templates for reproduction cause mutation-accumulation bottlenecks. These bottlenecks can impose demographic and evolutionary limits on the rate of adaptive evolution. We also show that predictions of adaptive optima drawn from equilibrium models are valid as a special case within the spectrum of modes of viral intra-cellular replication.

1 - Emory University, Dept of Biology: Population Biology Ecology and Evolution Program, 201 Dowman Drive, Atlanta, GA, 30322, United States
2 - Emory University School of Medicine, Department of Human Genetics, 615 Michael Street, Suite 301, Atlanta, GA, 30322, United States
3 - Emory University, Department of Biology, 201 Dowman Drive, Atlanta, GA, 30322, United States

Keywords:
none specified

Presentation Type: Regular Oral Presentation
Session: 90
Location: Alpine C/Snowbird Center
Date: Sunday, June 23rd, 2013
Time: 4:30 PM
Number: 90005
Abstract ID:682
Candidate for Awards:W.D. Hamilton Award for Outstanding Student Presentation