The ripA genomic region and transcript analysis. (a) Graphical representation of the F. tularensis LVS ripA genomic region. Primers utilized for RT-PCR are marked with arrows while the region complementary to the RNA probe used in the Northern analysis is demarcated by a solid line. (b) RT-PCR analysis of the expression of genes FTL_1912 (F12-R12), FTL_1913 (F13-R13), and ripA (F14-R14) are shown in the upper image. Analysis for transcripts bridging FTL_1912 to FTL_1913 (F12-R13) and FTL_1913 to ripA (F13-R14) shown in lower image and compared to the intrageneic ripA amplicon (F14-R14). PCR of cDNA demarcated by a (+) and reverse transcriptase negative reactions to assess DNA contamination marked as (-). (c) Northern analysis to evaluate the transcript size of ripA containing RNA. Roche digoxigenin labeled RNA ladder is present in the left most lane followed by total RNA from F. tularensis LVS (wt) and F. tularensis LVS ripA:: Tn5. This analysis used a ripA complementary digoxigenin labeled RNA probe demonstrating the presence of monocistonic ripA transcript in LVS and the absence of the transcript in F. tularensis LVS ripA:: Tn5.