Epithelial-mesenchymal interactions in differentiation of stomach epithelium in fetal mice.

Epithelial-mesenchymal interactions during development of the forestomach and glandular stomach in fetal mice were investigated by recombination experiments in vitro. Stomach epithelium could not survive when cultivated alone, but its development was supported by the presence of homologous or heterologous mesenchyme. The developmental fate of the epithelium was not affected by recombination with heterologous mesenchyme, but the expression of epithelial differentiation was influenced by the type of mesenchyme. The rate of keratinization of the forestomach epithelium was significantly greater on recombination with homologous mesenchyme than on recombination with heterologous mesenchyme. Moreover, the rate of formation of glandular structures in the glandular stomach epithelium was significantly greater on recombination with 16.5-day stomach mesenchyme than on recombination with 14.5- or 18.5-day stomach mesenchyme.