Fig 6. Effects of codY point mutations on expression of five C. difficile genes.

Three-to-four individual cultures of wild-type strain UK1, its codY null mutant and five different codY point mutant strains were grown in TY medium to an OD₆₀₀ = 0.4–0.6. RNA was extracted and assayed by qRT-PCR for the potential target genes R20291_2712 (encoding a peptidase), R20291_1235 (encoding chloromuconate cycloisomerase), R20291_1413 (ilvC), R20291_1698 (encoding a cell surface protein) and R20291_ 0812 (glgC). Counts were normalized to those for the rpoA gene and presented relative to the counts obtained with the wild-type strain.