Most epithelial tissues are homogeneous, being composed of a single cell type, but a few contain more than 1 type, raising questions about the mechanism of development of cell identity. Among the latter, the cells of the renal collecting tubule are probably the best studied, be it in their physiology, cell biology, or development. The cortical and medullary collecting tubules are derived from the ureteric bud and contain a majority cell type, the principal cell (PC), which mediates Na+ and water transport, and the intercalated cell (IC), which exists in 2 types: A (or α) and B (or β).
Most epithelial tissues are homogeneous, being composed of a single cell type, but a few contain more than 1 type, raising questions about the mechanism of development of cell identity. Among the latter, the cells of the renal collecting tubule are probably the best studied, be it in their physiology, cell biology, or development. The cortical and medullary collecting tubules are derived from the ureteric bud and contain a majority cell type, the principal cell (PC), which mediates Na+ and water transport, and the intercalated cell (IC), which exists in 2 types: A (or α) and B (or β).