FIG. 2.

Comparative measurement of transcription of CP synthesis-related genes. The relative transcript levels of the CP synthesis-related genes were determined in the S. aureus NCTC 8325 wild type (WT), the luxS mutant (SX1), and the luxS mutant with 39 nM AI-2 complementation (SX1 + AI-2). Strains were grown in LB medium with shaking at 37°C to an OD₆₀₀ of 2.1. AI-2 was added to the luxS mutant at the inoculation time to a final concentration of 39 nM. The RNA was extracted and transcription was quantified by real-time RT-PCR for the CP synthesis-related genes (represented by capA, capC, capE, capG, capI, capK, and capN). The quantity of cap cDNA measured by real-time PCR was normalized to the abundance of 16S cDNA within each reaction mixture. Error bars indicate the variance between triplicate samples within the real-time PCR. The relative cDNA abundance in the wild-type samples was arbitrarily assigned a value of 1.