The Section on Developmental Gastroenterology and Nutrition was established to study (1) intestinal epithelial cell migration and differentiation and (2) the nutritional modifications of gene activity and expression in the pancreas of developing and adult mammals. With respect to epithelial cell migration, our efforts have focused on the establishment of a primary cell culture system which will allow us to define those cell surface components which are responsible for cell attachment to the basement membrane. We are also continuing our research into the control of sucrase/isomaltase synthesis and degradation and the mode of incorporation of the complex into the intestinal brush-border membrane. Primary cultures of rat pancreatic exocrine cells were established to elucidate the role of nutrition in the modulation of gene activity and expression. Studies are focusing on the mechanism of adaptation of rat amylase in cultured cells and intact pancreas to carbohydrate in the media or the diet.