“…Myosin-II motors arranged at an angle to each other and bound to different actin filaments would slide the intact filaments past one another. The idea of myosin-II bouquets functioning as a motor unit is attractive because of the observed myosin-II clustering (Schroeder, 1990;Stachowiak et al, 2014;Takaine et al, 2015;Wollrab et al, 2016;McDonald et al, 2017) and the proposal that contractile units exist in the CRs of multiple organisms (Carvalho et al, 2009;Silva et al, 2016;Thiyagarajan et al, 2017). However, the finding that furrow ingression initiates while F-actin is still randomly oriented at the division plane (Spira et al, 2017) suggests that an alternative mode of contraction could be at work, at least early in cytokinesis.…”