Forkhead Box Protein B1 (FOXB1)

Fork head b1 is a winged helix transcription factor gene whose widespread early expression in the developing neural tube is soon restricted to the ventral and caudal diencephalon. During diencephalic neurogenesis, Foxb1 is expressed in one patch of neuroepithelium comprising a large mammillary portion and a smaller tuberal portion. The labeled cells coming from this patch contribute to nuclear formation by means of two different strategies: (1) caudally, the young neurons aggregate and settle immediately, giving rise to the nuclei of the mammillary body; (2) rostrally, the young neurons separate from the neuroepithelium forming a trail of cells which spans the mantle layer mediolaterally and which will give rise to two separate cell groups (the dorsal premammillary and part of the lateral hypothalamic area).