Sertoli cell junctions in the germ cell-free testis of the congenic mouse.

Intercellular junctions between the Sertoli cells in the germ cell-free testis of the congenic mouse were studied during ontogeny. In freeze-fracture replicas, these junctions are characterized by a great number of parallel occluding junctions, in which the particles are preferentially located in the center of the grooves in the E face. These particles appear to be arranged in discrete rows in both P and E fracture faces. In the initial stages of junction formation, large gap junctions with hexagonally packed particle aggregates and particle-free regions are observed. In the later stages, short segments of the occluding junctions are found associated with gap junctions. In later stages, the gap junctions diminish in size and number. These junctions are quite similar to those between Sertoli cells in the normal mouse and rat reported previously. The Sertoli cell junctions develop in the absence of the spermatogenic cells of this congenic mouse.