Chromosome organization in the absence of parS sites. (A) Schematic diagram of the eight origin-proximal parS sites (purple triangles). The five parS sites tightly clustered around the origin are depicted below the schematic. (B) Quantitative analysis of chromosome organization in strains lacking the three dispersed parS sites at -26°, +15°, and +40° (Δ3 parS); lacking all eight parS sites (Δ8 parS); or with a single consensus parS or parS* site at -7°. CFP reporters inserted at +28°, -35°, -61° were analyzed relative to the -7° YFP reporter. (C) Localization of GFP-Spo0J (false-colored green) at an early stage of sporulation in wild-type, or strains lacking all eight parS sites (Δ8 parS), containing a single consensus parS site at -7° (-7°::parS) or a mutated parS site (parS*) at the same position. Membranes (false-colored red) were stained with the dye TMA-DPH. (D) Immunoblot analysis of the strains shown in C. In the absence of the eight parS sites, GFP-Spo0J remained intact and the levels of Soj and SMC were similar to wild-type. GFP-Spo0J was analyzed using anti-GFP antibodies and the caret identifies the predicted size of free GFP. All strains efficiently entered sporulation as judged by the levels of the sporulation transcription factor σF. σA was used to control for loading.