Fig. 1.

Relative stability of the various modular replicons in different species and strains of Clostridium. R = Plasmid loss in media lacking supplementation with antibiotic as a function of time and measured as loss of antibiotic resistance. Each replicon based plasmid is compared to the stability of a cell carrying the antibiotic gene in the chromosome. For comparison, the projected rate of loss of a population carrying a plasmid that cannot replicate (‘Suicide’) is given.