Adhesion among neural cells of the chick embryo. III. Relationship of the surface molecule CAM to cell adhesion and the development of histotypic patterns.

Abstract

A molecule (named cell adhesion molecule [CAM]) that is involved in the vitro aggregation of neural cells from chick embryos was previously identified. Specific anti-CAM antibodies were used to demonstrate that CAM is localized in neural tissues and is associated with the plasma membrane of retinal cells and neurites. By antibody absorption techniques the decreased adhesiveness of cultured retinal cells obtained originally from older embryos were correlated with a decrease in the density or accessibility of cell adhesion molecules on the surface of these cells. The central role of CAM in neural cell aggregation was established by the observation that anti-CAM Fab'' fragments inhibit adhesion between neural cells in a variety of assays. To investigate the function of CAM and cell adhesion in developing tissues, aggregated of retinal cells that are capable of forming histotypic patterns in vitro were cultured in the presence and absence of anti-CAM Fab''. The Fab'' inhibited sorting out of cell bodies and neurites and decreased the number of membrane-membrane contacts, suggesting that CAM is associated with cell-cell, cell-neurite and neurite-neurite interactions.