FIG. 7.

Fold differences in ′lacZ mRNA in B. quintana containing the reporter construct pHPRO⁺ LACZ⁺ (white) or the control plasmids pHPRO⁻ LACZ⁺ (black) and pHPRO⁺ LACZ⁺ (N.D., not detectable), under conditions of (A) low heme (0.05 mM) or (B) low O₂ (5%) relative to normal conditions (0.15 mM heme or 21% O₂, respectively). A representative experiment is shown, where C_T values were determined in triplicate. SD bars were generated by comparing fold differences to those obtained from a second independent triplicate determination. All strains were grown in the environments indicated, and mRNA preparations were made at mid-log phase.