Percentage abundances of repHI2 gene and fitness costs of plasmid carriage in evolved populations and clones. (A) Relative abundance of repHI2 gene in evolved populations. (B) Detection of repHI2 gene in evolved clones. (C) Relative fitness of 20 evolved ATCC 14028 clones bearing evolved pJXP9 versus ATCC 14028::lux+pJXP9 by competition assays. (D) Relative fitness of 7 ancestral ATCC 14028 clones bearing evolved pJXP9 (transconjugants) versus ATCC 14028::lux+pJXP9 by competition assays. (E to G) Lag time (E), growth rates (F), and culture density (max OD600 values) (G) were calculated for 7 evolved clones bearing evolved pJXP9, corresponding transconjugants, and ATCC 14028::lux+pJXP9. All data from at least three biological replicates are presented as the mean ± SD, and the significance was determined by nonparametric one-way ANOVA (*, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001).