FIG 9.

Hemispheres of stable PG are maintained in ΔmapZ and ΔdivIVA cell division mutants, but ΔdivIVA mutants exhibit alternating patterns of new and old PG along the lengths of cells. Strains IU1824 (D39 Δcps rpsL1 parent), IU5661 (ΔdivIVA), and IU9175 (ΔmapZ) (see Table S1 in the supplemental material) were grown exponentially in BHI broth, labeled with HADA (pseudocolored green; old PG), washed, and chased in the presence of TADA (pseudocolored red; newly synthesized PG) as described in the legend to Fig. 2 and in Materials and Methods. Live cells were imaged by epifluorescence phase-contrast microscopy at the indicated time points after the removal of HADA (chase) and the addition of TADA. Similar labeling patterns were observed for >200 individual cells in diplococci or chains examined for each strain in microscopic fields at different time points after the start of the chase/TADA labeling in two biological replicates, and representative images are shown. Scale bar = 1 μm. P, phase-contrast image; H, HADA labeling (old PG); T, TADA labeling (new PG synthesis); O, overlay of H and T images.