Cytokinesis of neuroepithelial cells can divide their basal process before anaphase

Abstract

Neuroepithelial (NE) cells, the primary stem and progenitor cells of the vertebrate central nervous system, are highly polarized and elongated. They retain a basal process extending to the basal lamina, while undergoing mitosis at the apical side of the ventricular zone. By studying NE cells in the embryonic mouse, chick and zebrafish central nervous system using confocal microscopy, electron microscopy and time-lapse imaging, we show here that the basal process of these cells can split during M phase. Splitting occurred in the basal-to-apical direction and was followed by inheritance of the processes by either one or both daughter cells. A cluster of anillin, an essential component of the cytokinesis machinery, appeared at the distal end of the basal process in prophase and was found to colocalize with F-actin at bifurcation sites, in both proliferative and neurogenic NE cells. GFP-anillin in the basal process moved apically to the cell body prior to anaphase onset, followed by basal-to-apical ingression of the cleavage furrow in telophase. The splitting of the basal process of M-phase NE cells has implications for cleavage plane orientation and the relationship between mitosis and cytokinesis.

Neural progenitors, neurogenesis and the evolution of the neocortex

“…oblique and horizontal) cleavages. Moreover, the basal process, which, at early developmental stages when NECs prevail, may be split into two and inherited by both daughter cells (Kosodo et al, 2008), becomes much longer when NECs transform into aRG and typically does not split upon aRG division, constituting a single object that can only be inherited by one of the daughter cells.…”

Asymmetric inheritance of the apical domain and self-renewal of retinal ganglion cell progenitors depend on Anillin function

“…S2A-C) and performed all analyses in mosaic zebrafish embryos as previously described (Jusuf et al, 2012). Live imaging of dividing transplanted progenitor cells labelled with H2B-RFP (nuclei, red) and LifeAct-Venus (F-actin, yellow; Riedl et al, 2008) highlighted the appearance of an F-actin-enriched spot at the basal side of the cell body before anaphase (Kosodo et al, 2008) and its basal-apical displacement during cytokinesis (supplementary material Fig. S2D,E), indicating that vertical furrowing progresses normally in the mononucleated anillin hypomorphic cells.…”

The vertebrate-specific Kinesin-6, Kif20b, is required for normal cytokinesis of polarized cortical stem cells and cerebral cortex size

“…Cytokinetic furrowing starts at the basal side and ingresses toward the apical membrane, where the midbody is formed (Dubreuil et al, 2007). Cytokinetic abscission is mediated by the midbody at the ventricle only after the daughter nuclei have migrated away (Kosodo et al, 2008). The mechanisms of this specialized cytokinesis are not understood.…”