A group of cells of a particular organ whose position and fate are specified with respect to the same set of boundaries. The field has a definite boundary and the organ forms only from interactions between cells within the field. Gradients within the field can serve as a source of positional information as to where cells should go in the field. When the general fate of such a field is determined, it will give rise to a particular organ (e.g., eye, heart) and one of the first to be identified was the limb field consisting of mesodermal cells. During the 1960s, the concept of morphogenetic fields gave way to the operon model of differential gene transcription. Since the 1990s, however, it has become re-established, partly due to the fact that molecular markers of such fields (e.g., cardiac fields of the chick embryo) have been identified).
See Dynamical systems theory (development and evolution), Homeodomain proteins and homeobox genes, Hox genes, Induction (embryology), Jacob-Monod operon model, Limb bud, Maturational gradients, Mesoderm, Morphogenesis, Organizer (embryology), Pattern formation