Adherens junction dynamics in the testis and spermatogenesis.

Anchoring or adhering junctions are points at which cells attach to neighboring cells. They play an important role in determining and maintaining tissue organization (for reviews, see Yap et al, 1997; Tsukita et al, 2001; Cheng and Mruk, 2002). In the testis, unique cell-cell actin-based adherens junctions (AJs) between Sertoli cells, as well as between Sertoli and germ cells, and cell-cell intermediate filament-based desmosome-like junctions between Sertoli and germ cells (for reviews, see Russell and Peterson, 1985; Russell et al, 1990; Byers et al, 1993; Russell, 1993) not only provide mechanical adhesion of germ cells onto Sertoli cells, they also play a crucial role in germ cell morphogenesis and differentiation (Ozaki-Kuroda et al, 2002). In addition, the turnover of these junctions in the testis is important for permitting germ cell translocation from the basal compartment to the adluminal compartment of the seminiferous epithelium to complete spermatogenesis. In this review we limit our discussion to the recent and crucial development of the study of AJs instead of desmosome-like anchoring junctions because the latter type has been reviewed elsewhere (Russell and Peterson, 1985; Russell et al, 1990; Byers et al, 1993; Russell, 1993).