Figure 1

Analysis of cotranscription of fri, lmo0944 and lmo0945 genes by RT-PCR. (A) Scheme for transcriptional analysis of the genomic region comprising the fri, lmo0944 and lmo0945 genes. The template RNA was isolated from exponential-phase cultures of L. monocytogenes EGD grown in BHI broth at 37°C without antibiotics or with 0.09 μg/ml penicillin G. Gray arrows indicate the positions of the primers used in RT reactions and black arrows indicate the positions of primers used for PCR. Black lines labeled 2 through 11 show the positions of the expected products. The RT-PCR product labels correspond to the numbering of the agarose gel lanes in panel B. (-) or (+) indicate the expected products amplified using the RNA templates isolated from cells grown without antibiotics or with penicillin G, respectively. (B) The products obtained in RT-PCR reactions. The expected size of the amplified fragments of fri, lmo0944 and lmo0945 was 288 bp, 212 bp and 332 bp, respectively. A 100-bp ladder (lane 1) is shown as a size marker. In all cases, control PCRs were performed to confirm the complete removal of DNA from the RNA preparations prior to reverse transcription (data not shown).