Abstract
While mechanisms of cytokinesis have been identified in single cell models, the spatial and temporal regulation in developing tissues is less understood. Here we compare cytokinetic furrowing and abscission in mouse neuroepithelial stem cells (NESCs) at different developmental stages and in a cytokinesis mutant. We image abscission dynamics in this polarized epithelium for the first time. We find that furrows of NESCs ingress asymmetrically at a steady rate, and form the midbody at the apical membrane. Abscission is usually observed on each midbody flank, releasing the midbody remnant onto the apical surface. Interestingly, midbody remnants are more associated with early proliferative divisions. In the microcephalic Kif20b mutant, NESC abscission is accelerated, and daughter cells show increased cell cycle exit that is p53-independent. These results suggest that abscission in stem cells is developmentally regulated to influence daughter cell fates and ensure proper brain growth and structure.