DIFFERENTIATION OF THE DIGESTIVE TRACT EPITHELIUM UNDER THE INFLUENCE OF THE HETEROLOGOUS MESENCHYME OF THE DIGESTIVE TRACT IN THE BIRD EMBRYOS

Abstract

The endoderm of the esophagus, proventriculus, gizzard or small intestine of the 5 day old chick or quail embryo was cultivated in combination with homologous or heterologous mesenchyme on a Wolff and Haffen medium 7-21 days or on the chorio-allantoic membrane (CAM) for 8 days. With homologous mesenchyme the epithelium always differentiated homotypically. In association with heterologous mesenchyme the differentiation of the epithelium was both homotypical and heterotypical depending on the region of the digestive tract. The esophagus and small intestine differentiate mainly homotypically both in culture and on CAM but the gizzard and proventriculus show heterotypic differentiation particularly on CAM. The endoderm of the digestive tract of the 5 day old chick or quail embryo, though determined, still reacts to the heterologous stimuli of the mesenchyme to some degree.