Hox genes are not expressed in the forebrain and midbrain. Nevertheless, as in the hindbrain and spinal cord, forebrain cell types retained patterning gene expression. For example, the forebrain patterning gene Foxg1 was found in all forebrain neurons, as well as in telencephalon-specific astrocytes. Dorsoventral patterning was also preserved: the dorsal gene Emx1 was expressed in cortical, hippocampal, and striatal projection neurons, whereas ventral Dlx1 and Dlx5 were found mainly in inhibitory neurons of the same tissues.
