ResearchWorks Archive
    • Login
    View Item 
    •   ResearchWorks Home
    • Faculty and Researcher Data and Papers
    • Biology, Department of
    • Biology ePrints
    • View Item
    •   ResearchWorks Home
    • Faculty and Researcher Data and Papers
    • Biology, Department of
    • Biology ePrints
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Evolution of Mutator Genes in Bacterial Populations: The Roles of Environmental Change and Timing

    Thumbnail
    View/Open
    TanakaEtAl.pdf (143.9Kb)
    Date
    2003-07
    Author
    Tanaka, Mark M.
    Bergstrom, Carl T.
    Levin, Bruce R.
    Metadata
    Show full item record
    Abstract
    Recent studies have found high frequencies of bacteria with increased genomic rates of mutation in both clinical and laboratory populations. These observations may seem surprising in light of earlier experimental and theoretical studies. Mutator genes (genes that elevate the genomic mutation rate) are likely to induce deleterious mutations and thus suffer an indirect selective disadvantage; at the same time, bacteria carrying them can increase in frequency only by generating beneficial mutations at other loci. When clones carrying mutator genes are rare, however, these beneficial mutations are far more likely to arise in members of the much larger nonmutator population. How then can mutators become prevalent? To address this question, we develop a model of the population dynamics of bacteria confronted with everchanging environments. Using analytical and simulation procedures, we explore the process by which initially rare mutator alleles can rise in frequency. We demonstrate that subsequent to a shift in environmental conditions, there will be relatively long periods of time during which the mutator subpopulation can produce a beneficial mutation before the ancestral subpopulations are eliminated. If the beneficial mutation arises early enough, the overall frequency of mutators will climb to a point higher than when the process began. The probability of producing a subsequent beneficial mutation will then also increase. In this manner, mutators can increase in frequency over successive selective sweeps. We discuss the implications and predictions of these theoretical results in relation to antibiotic resistance and the evolution of mutation rates.
    URI
    http://hdl.handle.net/1773/1993
    Collections
    • Biology ePrints [44]

    DSpace software copyright © 2002-2015  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    @mire NV
     

     

    Browse

    All of ResearchWorksCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    DSpace software copyright © 2002-2015  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    @mire NV