Masa Onishi Finds a Surprise in Cell Division Study

Professor Masayuki Onishi has published “Cleavage-furrow formation without F-actin in Chlamydomonas” (PNAS Aug. 4, 2020. 117 (31): 18511ff.) based on postdoctoral research he did at Stanford. Masa studied how cells without a canonical division machinery, the contractile actomyosin ring, can form a cleavage furrow. Surprisingly, although the myosin-less furrows are still associated with F-actin, complete removal of this structure caused only partial delay rather than complete blockage of cytokinesis. In contrast, the microtubule cytoskeleton is tightly associated with the actin-less furrows and absolutely required for their ingression. This paper establishes the starting line for the lab’s future exploration of the fundamental core mechanisms of cytokinesis and their evolution in a diverse range of organisms.