FIG. 3.

RT-PCR confirmation of altered gene expression levels in the M. tuberculosis sigM-overexpressing strain. Gene expression levels observed to be upregulated in the sigM-overexpressing strain relative to the wild-type strain by microarray analysis were evaluated by quantitative RT-PCR. M. tuberculosis expression levels of the genes of interest in these two strains were measured as described in Materials and Methods and normalized to sigA, an essential sigma factor gene whose expression was not altered in the sigM-overexpressing strain (data not shown). The expression (n-fold) indicates the ratio of normalized gene expression levels in the sigM-overexpressing strain relative to those in the wild type. Error bars indicate standard deviations.