Development of junctions during differentiation of lens fibers.

Throughout the differentiation of eye lens epithelium into fibers, an extensive system of intercellular junctions develops. The junctional assembly is initially characterized by the accumulation of 9.0-nm intramembranous particles, forming linear rows in the matching plasma membranes of adjoining fibers. At the final stage of the fiber differentiation, the junctional particles are assembled in geometrically packed arrays. The formation of linear rows and bidimensional lattices of intramembranous particles probably favors reciprocal recognition of cell surfaces and specific cell-to-cell interlocking. Moreover, the existence of a rather rigid lipid core of the plasma membrane of eye lens fiber may promote the clustered distribution of intramembranous particles and facilitate the junctional assembly.