FIG. 2.

Evolution of the ratio of strains in cocultures of S. enterica serovar Typhimurium strains carrying or lacking the Gifsy-1 and Gifsy-2 prophages. The experiment was performed as described in the legend to Fig. 1. (A) The naive strain, MA6055, is susceptible to infection by both Gifsy-1 and Gifsy-2 phages. (B) The naive strain, MA7467, carries an ompC gene disruption that renders the strain resistant to Gifsy-1 and Gifsy-2 infection. Lysogenization by the indicated phage(s) is indicated by a double colon. The full genotypes of competing strains follow: MA5958, carrying Gifsy-1 and Gifsy-2 (Gifsy-1[+]Gifsy-2[+]); MA6055, see the legend to Fig. 1; MA7467, lacking Gifsy-1 and Gifsy-2 but with ompC159::Tn10 ara907 araD901::MudJ. The full genotypes of phage indicator strains follow: MA6685, lacking Gifsy-1 but carrying Gifsy-2 galE496 bio-106::Tn10; MA7416, carrying Gifsy-1 and lacking Gifsy-2 but carrying galE496 bio-106::Tn10. Panel A shows the result of one representative experiment of two independent experiments.