Lamellipodium Locomition of the Daughter Cells Facilitates the Cytokinesis of NRK Cells without Myosin II

Cytokinesis B serves as a backup mechanism in some mammalian cells after cytokinesis A failure. However, its mechanism remained poorly understood. Here, we applied cytochalasin D, an known actin inhibitor, globally during cytokinesis of NRK cells or cells dividing using cytokinesis B. Different from large fan-shaped lamellipodia at the leading edge during cytokinesis B, the progression of cytokinesis B was obvious inhibited in presence of 1 μM cytochalasin D. Pole to pole distance and cellular apparent surface area of the two daughter cells during cytokinesis B decreased significantly in presence of 1 μM cytochalasin D. Immunofluorescence staining revealed that a mass of actin was found to recruit from the cytoplasm to the fan-shaped leading lamellipodia of daughter cells in cells treated with blebbistatin. Our results indicated that lamellipodium locomition of the daughter cells mediated by actin which generated active traction force facilitated the progression of cytokinesis B.