Classically, it has been widely accepted that epithelial hypophysis develops from the stomodeal ectoderm. This notion was based on purely morphological observation of normal specimens. Recently, evidence is being accumulated that indicates another lineage for the developmental origin of adenohypophysis. This minireview focuses on several series of experimental works that have demonstrated a neuroectodermal origin of the hypophysis in vertebrates from amphibians to mammals. Phylogenetic consideration of the pituitary-like structures of prechordal animals is also presented.
(c) 2002 Elsevier Science (USA)