FtsZ at mid-cell is essential in until the late stage of constriction.

There has been recent debate as to the source of constriction force during cell division. FtsZ can generate a constriction force on tubular membranes , suggesting it may generate the constriction force . However, another study showed that mutants of FtsZ did not affect the rate of constriction, whereas mutants of the PG assembly did, suggesting that PG assembly may push the constriction from the outside.