Fig. 7: Cell wall turnover precedes and colocalises with S-layer expansion in dividing C. crescentus cells.

a Three-colour labelled C. crescentus cells, pulse-labelled with SC-mRFP1 (magenta), chased with SC-sfGFP (green). Channels showing S-layer labelling are merged (third panel) and the HADA fluorescence shown in cyan (fourth panel). Calibration bars are provided for each channel. Scale bars = 5 µm. Demographs of labelled C. crescentus cells ordered by length (n = 100 cells), showing (b) SC-sfGFP, (c) SC-mRFP1, and (d) HADA fluorescence profiles for each cell. HADA signal localises to the mid-cell at shorter cell lengths than SC-sfGFP, which precedes an apparent colocalization of the sfGFP and HADA signals. The HADA signal at mid-cell eventually subsides, concurrent with further new S-layer insertion. Demograph intensities are calibrated to the same levels as in (a). PCC scores (R-values) for correlation of HADA with sfGFP and HADA with mRFP1 signals, comparing (e) dividing and (f) non-dividing cells. R-values are displayed next to their respective cells in the relevant channels. Scale bars = 1 µm. g PCC scores (R-values) between HADA and sfGFP or mRFP1 channels for dividing (n = 45) and non-dividing (n = 31) cells measuring colocalization (horizontal lines signify mean of the dataset). Dividing cells show a significantly higher R-value between HADA and sfGFP () compared to mRFP1 () (measured by two-tailed Student’s t test, p < 0.0001 for dividing cells and ns for non-dividing cells), suggesting stronger colocalisation. Non-dividing cells showed a negative PCC R-value on average for HADA correlation between both sfGFP () and mRFP1 () signals, with no significant difference (measured by two-tailed Student’s t test, p = 0.070). Source data are provided as an accompanying Source Data file.