FIG 7.

Mg²⁺ modulates the frequency of Z-ring assembly. WT cells harboring P_xyl-GFP-zapA (BTG186) were cultured in CH* with 2.0 mM xylose. 10.0 mM MgCl₂ was added as indicated. (A) Representative growth curves. (B) Scatterplots showing the distribution of cell lengths. The bars represent the mean cell lengths of 800 cells ± the SDs. (C) Representative micrographs following the staining of membranes and nucleoids with FM4-64 and DAPI, respectively. The images are scaled identically. The arrowheads indicate examples of cells with four nucleoid masses and Z-rings that lack septa (yellow), 1 nucleoid mass (white), 2 nucleoid masses (blue), or partial septa (green). (D) Fraction of cells with the indicated number of nucleoids from three independent biological replicates. (E) Average number of Z-rings per unit cell length ± SD. Each circle represents the mean of 300 cells from three independent biological replicates per condition. (F) Average fraction of cells with coalesced ZapA-GFP that presented the indicated septum type ± the SD. Each circle represents the mean of 300 cells from three independent biological replicates per condition. *, 0.01 < P ≤ 0.05, **, 0.001 < P ≤ 0.01; (ns) P ≥ 0.05.