Spermiogenesis - Spermatogenesis

At the end of the meiosis the spermatids appear as simple spherical cells with a centrally located nucleus. Their differentiation into sperm requires an extensive morphological transformation. The various cellular organelles like mitochondria, golgi body and centrosomes contribute to such a transformation. The first step involves the formation of an acrosomal structure from the Golgi body. The acrosome lies proximal to the nucleus and forms a cap over the sperm nucleus. As the cap is formed the nucleus rotates and the acrosomal cap faces the basal membrane of the seminiferous tubule. This rotation is essential because the flagellum is to arise from the centriole on the other side of the nucleus. Subsequently the nucleus flattens-and condenses and there is a loss of cytoplasm. The mitochondria tend to form a ring around the base of the flagellum and become the neck region of the sperm. The fully formed sperm enters the lumen of the seminiferous tubule.