FIGURE 11.

In vivo localization of ΔN-FtsZ-GFP protein. (A) Genomic structure of strains CSSC19, expressing an FtsZ protein C-terminally fused to mut2-GFP, and CSSC18, expressing ΔN-FtsZ-mut2-GFP. A white sector in the left part of a ftsZ ORF denotes a deletion of the 2nd to 52nd codons rendering gene Δ5′-ftsZ. Sp^R represents a Sp-resistance genetic determinant included in the plasmid inserted in the chromosome (thin gray trace) (see section “Materials and Methods” for details). (B) Filaments of strains CSSC19 and CSSC18 grown in BG11₀ plus ammonium medium were visualized by confocal microscopy. Merged images of cyanobacterial autofluorescence (red) and GFP fluorescence (green) are shown. (C) GFP fluorescence (green) and autofluorescence (red) were recorded along a representative filament stretch (upper panels) of strains CSSC19 and CSSC18 in the area covered by the manually defined orange area (lower panels). Note that, whereas in both strains the autofluorescence decays in the intercellular zones, in CSSC19 the GFP fluorescence peaks at midcell. A tridimensional plot of the GFP fluorescence is shown in the lower part of the figure.