Early stages in the reorganization of dissociated embryonic chick skeletal muscle cells.

Abstract

Cell surface material and contact specializations were observed in embryonic chick skeletal muscle cells at early stages (prior to fusion) in monolayer culture. Ruthenium red-staining surface material was largely absent after prior treatment with trypsin. During reorganization into a tissue pattern dense staining amorphous material was seen at the cell surfaces and in the extracellular spaces of clustered cells; the free surface material was clumped, that between the cells more compact. This material appeared to be mucopolysaccharide and could be involved in adhesion. Numerous close junctions (intercellular space, 25–100 A), as well as occasional focal tight junctions (no apparent intercellular space), were observed between apposed cells. These junctions semmed related to cellular adhesion and perhaps also to electrical coupling.