Pax6 controls radial glia differentiation in the cerebral cortex.

Radial glia cells perform a dual function in the developing nervous system as precursor cells and guides for migrating neurons. We show here that during forebrain neurogenesis, the transcription factor Pax6 is specifically localized in radial glia cells of the cortex but not of the basal telencephalon. In Pax6-deficient mice, cortical radial glia cells were altered in their morphology, number, tenascin-C (TN-C) expression, and cell cycle. We show that some of these alterations are cell-autonomous, whereas others were rescued by coculturing with wild-type cortical cells. Our results suggest that Pax6 plays an essential role in the differentiation of cortical radial glia. Thus, despite their widespread distribution, radial glia cells are regionally specified in the developing CNS.