Intercellular junction development in maturing rat seminiferous tubules

Sertoli cells of the seminiferous tubules in immature rats (1–20 days) contain gap and tight junctions in different stages of development as identified in freeze-fracture replicas. Typical gap junctions and gap junction formation were observed between Sertoli cells. Tight junctions were observed to assume a variety of configurations including linear, macular, and extensive occluding complexes. Tight junction formation was also observed. A decrease in the frequency of gap junctions and a corresponding increase in the number of tight junctions was quantitatively shown.