Asymmetric division and polarity of neuroepithelial cells.

Neuroepithelial cells, the progenitors to the CNS neurons and glia, undergo both symmetric and asymmetric divisions. Symmetric divisions underlie the proliferation of neuroepithelial cells that predominates early in CNS development. Asymmetric divisions are thought to generate the cell types derived from neuroepithelial cells, such as neurons. Insight into the mechanism of asymmetric division of neuroepithelial cells has come from two lines of research, the study of their epithelial polarity and the analysis of the expression of vertebrate homologues of proteins known to be involved in cell fate determination in Drosophila.