Otx and Emx homeobox genes in brain development

A number of gene families have recently been identified that play a role in the control of the development of the central nervous system of vertebrates. Many of these genes are homeobox genes. The most well-known and best-studied among them are the Hox genes. Collectively, these control regionalization and cell identity in the developing hindbrain and spinal cord. Other homeobox gene families, including the Otx and Emx genes, control brain development. In particular, Otx2 seems to play a crucial role in the early establishment of the rostral brain; Otx1 and Otx2 cooperate to define the posterior boundary of midbrain; and Emx1 and Emx2 play a major role in the developing cerebral cortex, Some of these results may be relevant for the deeper understanding of congenital brain defects and multifactorial brain disorders.