Targeting of endogenous sulfated glycoprotein‐1 and ‐2 to lysosomes within nonciliated cells of the efferent ducts during postnatal development of the rat

Sulfated glycoprotein (SGP)-1 and -2, secretory products of Sertoli cells, are secreted into the lumen of seminiferous tubules where they bind to late spermatids. Once released, the spermatozoa traverse the efferent ducts where these proteins detach from their surface and are endocytosed by the nonciliated cells. In adult animals, SGP-1 and SGP-2 are also synthesized by nonciliated cells and targeted from the Golgi apparatus to lysosomes. The …