Morphogenesis of the residual body of the mouse testis

Abstract
A histochemical study of the detached cytoplasm of the maturing spermatid has been carried out. The detached cytoplasm has been designated as the cytoplasmic body and 4 distinct phases in its morphogenesis have been reported. The cytoplasmic tag of stage 11 of spermiogenesis has been designated as phase CB-I in the morphogenesis of the cytoplasmic body. It was found to contain numerous granules of RNA, poly-saccharides, and lipid. During phase CB-2 and CB-3, coalescence and fusion of these granules occurs, which result in a centrally-oriented plaque of RNA and glycogen, peripheral satellites containing polysaccharides, and large globules of lipid. During phase CB-4, the cytoplasmic body membrane becomes approximated to the plaque and at this stage of development the cytoplasmic body can be compared to the ‘residual bodies’ of Regaud. Peripheral migration towards the basement membrane of the seminiferous tubule now occurs. Some of the residual bodies undergo phagocytosis by Sertoli cells, while others eventually occupy a position at the level of the spermatogonia.