FIG. 1.
Growth of E. coli strains expressing different 16S alleles. Strain JM109 and Δ7 prrn strain AVS69009 were transformed with pBR322 derivatives harboring the E. coli rrnC operon carrying either the wild-type or mutant allele. These strains were compared for growth on nutrient agar at 30°C, 37°C, and 41°C by using Dunnett's statistical tests. Growth is expressed as colony size index (average size obtained for a strain with the Spcr 16S alleles divided by the average size obtained with the same strain expressing the wild-type allele at the same temperature). *, P < 0.001 by Dunnett's multiple-comparison test; #, P < 0.05 by Dunnett's multiple-comparison test.