FIG 7.

Regulation of ply, spxB and lctO genes by incubation with erythrocytes, hemoglobin, or heme. TIGR4 wt was inoculated into THY broth alone, THY broth containing 1% sheep erythrocytes, THY broth with 10 μM hemoglobin (Hb), or THY broth with 5 μM heme. Cultures were incubated for 2 h at 37°C in a 5% CO₂ atmosphere; bacteria were then harvested, and RNA was extracted from these cultures and utilized as the template in qRT-PCRs with primers that amplified ply, spxB, or lctO. Average C_T values were normalized to the 16S rRNA gene, and the fold differences relative to the THY control were calculated using the comparative C_T method (2^−ΔΔCT) (78).