Weakly Deleterious Mutations and Low Rates of Recombination Limit the Impact of Natural Selection on Bacterial Genomes.

ABSTRACT:

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Free-living bacteria are usually thought to have large effective population sizes, and so tiny selective differences can drive their evolution. However, because recombination is infrequent, "background selection" against slightly deleterious alleles should reduce the effective population size (Ne) by orders of magnitude. For example, for a well-mixed population with 10(12) individuals and a typical level of homologous recombination (r/m = 3, i.e., nucleotide changes due to recombination [r] occur at 3 times the mutation rate [m]), we predict that Ne is <10(7). An argument for high Ne values for bacteria has been the high genetic diversity within many bacterial "species," but this diversity may be due to population structure: diversity across subpopulations can be far hig

SUBMITTER: Price MN 

PROVIDER: S-EPMC4701828 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature