Figure.

Megakaryocyte progenitors must decide whether to divide to give rise to two daughter cells (top) or instead to commit to terminal differentiation and polyploidization (bottom). The switch from the proliferative cell cycle to the endomitotic one involves changes in activity and expression of several genes including RhoA, ECT2, GEF-H1, and MYH10. Most notably, the reduction in RhoA activity and MYH10 prevents the action of the contractile ring and the completion of cytokinesis. Inhibition of AURKA has been found to promote the endomitotic process over proliferation. Note that AURKA localizes to the bipolar spindles while active RhoA is associated with the cleavage furrow.