Figure 3.

Chromosomal and divisome events under slow growth conditions. (A). Cell division is accompanied by a change in nucleoid disposition, from sister nucleoids closely juxtaposed to mid-cell via their terminus regions to each nucleoid centrally positioned within its (future or existing) sister (daughter) cells. Note that septum closure and the nucleoid transition can occur in either order, implying that they are independent events. (B) The nucleoid transition in (A) involves a whole body movement of the nucleoid, with origin and terminus regions remaining in the same relative positions. (A,B) are from Bates and Kleckner (2005). (C) Sequence of chromosomal events including replication initiation; a prominent transition to nucleoid duality, accompanied by an exchange of places of one sister (marked by its origin) and the mother material (marked by its terminus), and ensuing terminus dynamics including splitting and transit of one terminus across midcell (from Joshi et al., 2011 based on data in Bates and Kleckner, 2005). (D). Divisome (FtsZ) assembly dynamics defined under slow growth conditions (from Coltharp et al., 2016) (middle and bottom) as compared to chromosomal events predicted by interpolation of data from similar conditions (Figure 1D) and the proposed progression permission/PCC model (Figures 1A,B).