Masayuki Onishi, October 4Please join the department of Biology in welcoming Dr. Masayuki Onishi, Assistant Professor of Biology at Duke University, for his talk entitled, "Cytokinesis without F-actin in Chlamydomonas - Exploiting phylogenetic diversity to elucidate general principles of cell biology." The talk will be held via Zoom on October 4, 2021 at 4pm EST. For access to the Zoom information, please contact Sarah Farris at firstname.lastname@example.org.
More on the talk:
The actomyosin ring has been believed to be essential for cleavage-furrow formation. However, type-II myosins are conserved only in unikonts (animals, fungi, and amoebae), while most other eukaryotes still divide by furrowing, suggesting a myosin-independent mechanism for furrowing that is widespread in modern eukaryotes that has been inherited from the common ancestor. Using one of the myosin-II-less organisms, Chlamydomonas reinhardtii, we reported previously that furrowing proceeds even in the complete absence of F-actin. We have since investigated the role of microtubules in furrow ingression. Through time-lapse imaging of EB1-mNG that tracks the growing tips of MTs, we found that dynamic cortical microtubule arrays nucleate out of the division plane in cells before and after mitosis, suggesting that there is a non-centrosomal microtubule-organization center (ncMTOC) in this region. We will discuss the roles of the ncMTOC and furrow-associated microtubule arrays in localizing two types of conserved kinesin proteins to potentially drive membrane ingression.