Role of scaffolding proteins in stalk elongation.

(A) DIC images of cells lacking single scaffolding proteins. The strains analyzed were LS4275 (ΔmreC Pxyl::Pxyl-mreC), LS3809 (ΔmreB Pxyl::Pxyl-mreB), CJW2747 (ΔrodZ::Ω Pxyl::Pxyl-rodZ), MT257 (ΔbacA). Strain NA1000 (WT) is shown as a wild-type control. Strains LS4275, LS3809, and CJW2747 were grown to exponential phase PYE medium containing the inducer xylose. Subsequently, the cells were washed, grown for another 7 h in PYE medium with or without inducer and then incubated for 24 h in M2G-P medium with or without inducer prior to imaging by DIC microscopy. Strain MT257 was grown to stationary phase in PYE medium, diluted (1:20) into M2G-P medium, and grown for 24 h prior to analysis. Strain NA1000 (WT) was grown in M2G-P medium. After 9 h, the cultures were supplemented with A22 at a final concentration of 10 μg/ml and incubated for additional 15 h prior to imaging (scale bar: 3 μm). (B) Distribution of cell body and stalk lengths in populations of WT NA1000 and depleted strains LS4275, LS3809, CJW2747, and MT257 grown as described in (A). The data are shown as box plots, with the horizontal line indicating the median, the box the interquartile range and the wiskers the 2nd and the 98th percentile (n = 208 per strain). In addition rotated kernel density plots (grey) are depicted for each dataset to indicate the distribution of the raw data (*** p −6; t-test). See S1 File for the raw data.