FIGURE 4:

Mechanics of cytokinesis in fission yeast. (A) Ingression of the cleavage furrow during cytokinesis involves assembly of the septum and constriction of the contractile ring (red). (B) Model of forces involved in furrow ingression at the leading edge of the furrow (blue arrow in A). Septum assembly provides the major force by pushing the membrane inward, opposing turgor pressure. The actin-based contractile ring (red), which is attached to the plasma membrane via membrane proteins (turquoise), provides relatively small pulling forces on the membrane, which may shape the septum by stimulating the activity of glucan synthases (bgs proteins, purple). Adapted from Proctor et al. (2012) and Zhou et al. (2015b).