Figure 2

gluQ-rs is co-transcribed with dksA in S. flexneri 2457T. A) Agarose gel showing the amplified product of the full-length operon extending from the dksA gene through the end of gluQ-rs (1.44 kpb). Total RNA isolated during mid log phase growth of S. flexneri was subjected to reverse transcriptase and PCR (RT-PCR) using primers opeF/opeR (Table 2). M: molecular marker, sizes are indicated. Lane 1: RNA treated with reverse transcriptase, Lane 2: genomic DNA isolated from S. flexneri 2457T, Lane 3: RNA without reverse transcriptase treatment, Lane 4: negative control of PCR reaction without DNA. B) Electrophoretic analysis of each amplified gene fragment, dksA (dksAF/dksAR; 436 bp), gluQ-rs (gQRSF/gQRSR; 508 bp), the intergenic region dksA/gluQ-rs (interF/interR; 496 bp) and the ribosomal RNA 16S (rrsHF/rrsHR, 589 bp). Total RNA isolated during different phases of the growth curve of S. flexneri 2457T was subjected to RT-PCR to detect the corresponding fragment. Lane 1: lag phase, Lane 2: early mid log phase, Lane 3: mid log phase, Lane 4: stationary phase. +: corresponds to amplification using genomic DNA. RNA: Isolated RNA without reverse transcriptase treatment. -: negative control PCR reaction without DNA. Each band was estimated using Image J software (V1.46) and its amount was estimated using the fragment corresponding to 500 bp of the DNA ladder.