title: Microbial diversity. Fine-scale diversity and extensive recombination in a quasisexual bacterial population occupying a broad niche.
abstract: Extensive fine-scale genetic diversity is found in many microbial species across varied environments, but for most, the evolutionary scenarios that generate the observed variation remain unclear. Deep sequencing of a thermophilic cyanobacterial population and analysis of the statistics of synonymous single-nucleotide polymorphisms revealed a high rate of homologous recombination and departures from neutral drift consistent with the effects of genetic hitchhiking. A sequenced isolate genome resembled an unlinked random mixture of the allelic diversity at the sampled loci. These observations suggested a quasisexual microbial population that occupies a broad ecological niche, with selection driving frequencies of alleles rather than whole genomes.
authors.affiliation: Applied Physics Department, Stanford University, Stanford, CA 94305, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Rosen
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Davison
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA. dbhaya@stanford.edu dsfisher@stanford.edu.
authors.forename: Devaki
authors.initials: D
authors.lastname: Bhaya
authors.affiliation: Applied Physics Department, Stanford University, Stanford, CA 94305, USA. Bioengineering Department, Stanford University, Stanford, CA 94305, USA. dbhaya@stanford.edu dsfisher@stanford.edu.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Fisher
mesh_terms: D000483:Alleles; D004777:Environment; D019143:Evolution, Molecular; D020641:Polymorphism, Single Nucleotide; D011995:Recombination, Genetic; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA; D046940:Synechococcus / Q000235:genetics*