Summary: During cytokinesis. a contractile ring consisting of unbranched filamentous actin (F-actin) and myosin II constricts at the cell equator. Unbranched F-actin is generated by formin. and without formin no cleavage furrow forms. https://www.roneverhart.com/Taylor-AD24ce-American-Dream-Acoustic-Electric-Guitar-Shaded-Edgeburst-p19272/