From fly head to mammalian forebrain: the story of otd and Otx.

Many of the genes responsible for axial patterning have been conserved throughout evolution. Recent studies of invertebrates and vertebrates are extending our understanding of this molecular conservation into the anterior region of the animal embryo, including the developing brain. These studies suggest that this domain is specified according to a genetic paradigm that is different from that governing trunk development, and are also beginning to provide insights into the structures that underlie the rostral brain.