SERTOLI-CELL - SPERMATID TUBULOBULBAR COMPLEXES IN THE RAM

The fine structure of the tubulobulbar complex (TBC) of the ram semini ferous epithelium was studied in immersion-fixed testicular samples ob tained in autumn (sheep's mating period). The TBC was visible during t he last two stages of the seminiferous epithelium cycle. It originated as a tubular invagination of the Sertoli cytoplasm harbouring a compl ementary evagination from the spermatid head. Later, it expanded into a bulbous structure, finally becoming detached from the spermatid and apparently phagocytosed by the Sertoli cell. The significance of this transient structure is discussed and compared with previous reports fo r other eutherian mammals.