Diminishing Returns of Population Size in the Rate of RNA Virus Adaptation
AUTOR(ES)
Miralles, Rosario
FONTE
American Society for Microbiology
RESUMO
Whenever an asexual viral population evolves by adapting to new environmental conditions, beneficial mutations, the ultimate cause of adaptation, are randomly produced and then fixed in the population. The larger the population size and the higher the mutation rate, the more beneficial mutations can be produced per unit time. With the usually high mutation rate of RNA viruses and in a large enough population, several beneficial mutations could arise at the same time but in different genetic backgrounds, and if the virus is asexual, they will never be brought together through recombination. Thus, the best of these genotypes must outcompete each other on their way to fixation. This competition among beneficial mutations has the effect of slowing the overall rate of adaptation. This phenomenon is known as clonal interference. Clonal interference predicts a speed limit for adaptation as the population size increases. In the present report, by varying the size of evolving vesicular stomatitis virus populations, we found evidence clearly demonstrating this speed limit and thus indicating that clonal interference might be an important factor modulating the rate of adaptation to an in vitro cell system. Several evolutionary and epidemiological implications of the clonal interference model applied to RNA viruses are discussed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=111865Documentos Relacionados
- The diminishing birth-rate
- Effective population size and the rate and pattern of nucleotide substitutions
- A Phylogenetic Estimator of Effective Population Size or Mutation Rate
- Local adaptation across a climatic gradient despite small effective population size in the rare sapphire rockcress.
- Effects of Restricted Population Size and Increase in Mutation Rate on the Genetic Variation of Quantitative Characters