Homeobox genes in gut development.

Classical descriptions of gut development specify subdivision into foregut, midgut, and hindgut together with their derivatives. This is based on the anatomical localisation of the anterior and posterior intestinal portals separating the roof of the yolk sac from the foregut and hindgut diverticulae. When considering the molecular basis of intestinal differentiation, it is necessary to think in terms of the genes involved, and in this respect those containing the homeobox motif are important players in specifying the fate of both the endodermal and mesodermal components of the gut. In this review, evidence is considered for their role, with particular regard to the acquisition of positional information.