Selective adhesive properties of cells are thought to have a key role in animal morphogenesis, but the molecular bases underlying these properties remain to be determined. Our studies have demonstrated that cell-type-specific adhesiveness resides in a class of cell-cell adhesion molecules, termed cadherins, which were defined as the molecular components of the Ca2+-dependent cell adhesion system (CADS). For example, a cadherin molecule identified in mouse teratocarcinoma cells, termed E-cadherin (this molecule seems to be identical to uvomorulin or cell-CAM 120/80 and equivalent to chicken L-CAM), was detected only in epithelial cells of various organs; it did not cross-react with cadherins on other cell types. We recently described a novel type of cadherin, N-cadherin, which is found in mouse cells and whose tissue distribution is distinct from that of E-cadherin. In the present study, we have identified a molecular component of N-cadherin in the chicken and determined its distribution in the tissues of early embryos. The results suggest that expression of this adhesion molecule is associated with separation and sealing of cell layers in morphogenesis.