Figure 6.

Proposed mechanisms for pushing forces that drive mitotic elongation in collagen gels. During interphase, cells are able to spread in collagen gels and remodel the surrounding network. When cells enter mitosis, they become rounded and prepare for division. From anaphase to T/C, cells generate extracellular protrusive forces through elongation of the interpolar spindle, which couples to the surrounding collagen matrix through the astral microtubules, and contraction of cytokinetic ring, which drives mitotic expansion due to volume conservation. Such protrusive forces push away the surrounding collagen fibers along the mitotic axis, and thereby generate space for mitotic elongation to proceed.