Organization and Redistribution of Adenosinetriphosphatase During Spermiogenesis in the Mouse

The origin and distribution of Ca2+-activated ATPase reaction sites were determined during spermatozoal differentiation and in the liberated sperm within the seminiferous tubule in the white mouse. In the spermatid, the reaction products first appear in the Golgi apparatus, inside the centriole during its attachment to the nucleus, in the dense body and inside the annulus, and later spread into the fibrillar components. During maturation, dense deposits of reaction products appear in the plasma membrane interfaces between Sertoli cell and spermatid. As the development of the spermatids proceeds and the maturing spermatozoa are liberated into the lumen of the seminiferous tubule, the reaction sites shift to the dense fibers and the fibrillar components. The reaction products appear as early as the spermatids show signs of contractility; an increasing amount appears with the later developmental stages and reaches a maximum when the spermatozoa are fully formed and have cast off their superfluous cytoplasm.