FIG. 4.

Duplicating the rod: some localized and oriented processes. (a) Actin-like cytoskeleton and dispersed synthesis of sidewall. Stippling indicates intensity of wall synthesis. (b) Segregation of nucleoids to the poles by an active mechanism; sidewalls elongate. (c) Cell finds its midpoint by the oscillation of Min proteins (nucleoid occlusion not shown). (d) Construction of divisome at the midpoint, wall synthesis focused there. (e) Construction of the septum, sidewall elongation ceases. Note that the cytoskeleton presumably undergoes rearrangements during the cell cycle which remain to be described.