FIG. 4.

Frequency of pyrF mutant generation in M. smegmatis. (A) Plasmid constructs. kan, kanamycin resistance gene; cm, chloramphenicol resistance gene; gm, gentamicin resistance gene; amp, ampicillin resistance gene; repA and repB, replication genes from pAL5000; open circle, E. coli ColE1 oriE; cross-hatched circle, E. coli P15A oriE; solid circle, pAL5000 oriM. (B) Plasmid loss and mutant isolation. Symbols: ▪, total Gm^r colonies (plasmid loss); □, white Gm^r colonies (pyrF mutants). The error bars indicate standard deviations from three separate experiments.