Actomyosin tube formation in polar body cytokinesis requires Anillin in C. elegans.

摘要: Polar body extrusion (PBE) is the specialized asymmetric division by which oocytes accomplish reduction in ploidy and retention of cytoplasm. During maternal gametogenesis, as male meiosis mitosis, cytokinesis accomplished a ring rich active Rho, myosin, formin-nucleated F-actin [1-7]. However, unlike wherein contractile encircles cell equator, polar assembles discoid cortical washer. Here we show that Caenorhabditis elegans, meiotic transforms during closure from disc above spindle to cylinder around midzone. The midbody tube comprises stacked cytoskeletal rings. This topological transition suggests novel mechanism for constriction an initially cytokinetic ring. Analysis mouse PBE indicates formation conserved process. Depletion scaffold protein anillin (ANI-1) C. elegans results large unstable bodies often fuse with oocyte. Anillin dispensable assembly, initiation, but required transform into tube. We propose bundling promotes tube, ensures fidelity PBE.