Fig. 9. Summary of developmental defects of the dorsal telencephalic midline
region of Hes1;Hes3;Hes5 cKO mice. (A)
In Hes1;Hes3;Hes5 cKO mice, the choroid plexus
epithelium (cpe) is lacking, and Cajal-Retzius (CR) cell formation in the
piriform cortex (pir) is enhanced. (B) Ngn2 promotes
Cajal-Retzius cell formation, whereas Hes genes regulate specification of the
choroid plexus epithelium by antagonizing Ngn2. In
Hes1;Hes3;Hes5 cKO mice, Ngn2 expression
is upregulated and Cajal-Retzius cell formation is enhanced, whereas choroid
plexus epithelial cells are lacking. ctx, neocortex; hem, cortical hem; emt,
eminentia thalami.