A membrane-associated patterning system (MinE, red) both depends on membrane-bound MinD (green), as well as causes its dissociation. In this way, a MinE maximum destabilizes itself, causing its shift towards a region of higher MinD concentration. On its way, the MinE wave removes MinD from the membrane. Shortly before the MinE wave reaches the pole, MinD and MinE concentrations collapse. Meanwhile, a new plateau of membrane-bound MinD is rising in the other part of the cell. A new high MinE concentration is triggered at its flank, causing this peak to disappear also, and so on. A system for septum formation is assumed to be also a pattern forming system (FtsZ, blue). An inhibition by MinD (green) is sufficient for a reliable localization of the FtsZ pattern in the center of the field. Note that in actual E.coli cells, the inhibition of FtsZ self-assembly is accomplished by the MinC protein which binds to, and co-oscillates with, MinD.