Expression of E-cadherin during craniofacial development.

The cell adhesion molecule E-cadherin is assumed to play an important role in organogenesis and histogenesis. We have analyzed the presence of E-cadherin during normal and disturbed craniofacial development with respect to palate and tooth formation by immunohistochemistry using a rat monoclonal antibody (DECMA-1) and by in situ hybridization using an oligonucleotide probe. Cleft palate was induced by retinoic acid (RA) treatment of pregnant dams. Normal and RA-treated fetuses of gestational days 14-18 were examined. E-cadherin was present in epithelia of both ectodermal and endodermal origin, including developing teeth and epithelia of the palate as well as respiratory and oral epithelia. The expression level of E-cadherin increased with age and differentiation. In normal fetuses, at day 18, the expression was higher in the epithelia of the oral cavity than in the forming nasal cavity. The expression pattern of E-cadherin implies that this molecule has a role during normal development of the epithelia of the craniofacial complex.