Fig 2. The SLczcD mediates temperature-dependent post transcriptional regulation of CzcD in C. jejuni.

a. Western blot analysis of the C. jejuni NCTC11168 CjCzcDhis strain and derivatives with deletion of the SLczcD (CjΔSL) and the derepressing mutation CC29,30GG (CjCC29,30GG). Standardised whole cell lysates were probed with anti-RecA (green) as a loading control and anti-histidine (red) to detect CzcD. Cultures were grown for 24 hours in MH broth at the temperatures indicated. All CzcD signals were standardised to the corresponding internal RecA loading control signal and normalised. Relative CzcD quantifications are provided below the blots normalised to the corresponding 32°C CzcD value for each of the three strains to allow effect of temperature to be quantified (upper row) or to the CjCzcDhis value at each temperature allowing comparison of CjΔSL and CjCC29,30GG strains with CjCzcDhis (lower row). These data are representative of at least three replicate experiments. b. RT-qPCR analysis of czcD expression levels for strain CjCzcDhis grown for 24 hours in MH broth at the temperatures indicated. The CT values were normalised against the data at 32°C. Data are the mean of three biological replicates with standard error indicated. Comparison of ΔΔCt mean values by t test gave non-significant p values of 0.90 (37 vs 32°C) and 0.78 (42 vs 32°C).