Figure 3

Peptidoglycan degradation along de sidewalls is anisotropic in ΔmreB cells. (a, b) TDL time-lapse pulse chase experiment in a microfluidics device. Wild-type (a) and ΔmreB (b) cells were grown in LB without added Mg²⁺, stained with TDL for 20 min, rinsed and further grown in LB. Images correspond to 0 min and 60 min after rinsing. Phase contrast (left) and epifluorescence (right) images are shown. Deformations of ΔmreB cells and the corresponding anisotropic loss of TDL label are indicated by white arrowheads (bulging cells) and arrows (bent cells). Scale bars, 2 µm. (c–f) SIM images of a similar TDL pulse-chase experiment performed in batch cultures. Wild-type (c) and ΔmreB cells growth in the presence (d) and in the absence (e, f) of added Mg²⁺. Cells were stained with TDL for 20 min, rinsed and allowed to grow for 35 min in fresh medium. SIM images of the cell top plane (i) and medial plane (ii) are shown. Scale bars, 2 µm.