Abstract
Histological sections of neonatal rabbit kidney of various ages were analysed to study the ontogeny of the collecting duct system. In addition, the sections were incubated with fluorescent wheat germ (WGA) and peanut agglutinin (PNA) to investigate the terminal differentiation of collecting duct cells. With both lectins we found different binding behaviours in the three segments of the collecting duct anlagen, the ampullary bud, the ampullary neck and the collecting duct. During the observed steps in development the lectin-binding pattern in the collecting duct and the ampullary neck appeared unchanged. In the collecting duct most cells reacted with WGA and only a few with PNA, while in the ampullary neck all cells bound both WGA and PNA. In the ampullary bud, however, the lectin-binding pattern changed between unlabelled and completely labelled stages with both lectins. The results indicate that both intercalated and principal cells originate from a common precursor cell.