Specific recognition of plasma membranes by embryonic cells.

Methods have been developed for preparation of plasma membrane fractions from embryonic neural retina and cerebellum. These membrane fractions are specifically bound by intact cells of the original tissue (homotypic binding) and not by cells from the other tissue (heterotypic binding). Aggregation of neural retina cells and cerebellar cells is prevented by addition of homotypic membranes but not by heterotypic membranes. We conclude that, under our assay conditions, these embryonic cells specifically recognize homotypic membranes, and that the specificity of recognition is the same as in the initial step in the process of cellular aggregation.