Differential expression of alpha N-catenin and N-cadherin during early development of chicken embryos.

alpha-Catenins are a group of proteins associated with cadherin cell-cell adhesion molecules, and play indispensable roles in the function of the cadherins. alpha N-catenin, a subtype, was identified as a protein associated with N-cadherin. In this study, we investigated the expression pattern of alpha N-catenin in early chicken embryos, and compared it with that of N-cadherin. alpha N-catenin was first detected in the closed somites and neural tube, and, at later stages, in many other tissues including the central nervous system (CNS), skeletal muscles, various regions of the overlying ectoderm, and some endodermal layers. In the CNS and skeletal muscles, both alpha N-catenin and N-cadherin were strongly expressed, and their distribution patterns were similar. However, in some parts of the ectoderm and endoderm, only alpha N-catenin was expressed. On the other hand, various mesenchymal tissues and peripheral nerves strongly expressed N-cadherin, but their alpha N-catenin expression was, in general, weak. Thus, the expression of these two proteins did not always correlate with each other. These results suggest that cells use different combinations of a cadherin and an alpha-catenin in a tissue-specific manner.