FIGURE 10.

Schematic representation of the internal mechanisms supporting the remodeling of the spermatid head. In early spermiogenesis steps the F-actin filaments and associated proteins forming the acroplaxome may be responsible for the first changes in nuclear shaping followed by the forces generated by the microtubules and actin filaments in the manchette and the interaction with the nuclear envelope through the linker of nucleoskeleton and cytoskeleton (LINC) complex, and final twists may be supported by chromatin condensation due to replacement of histones by transition nuclear proteins (TNPs) and then protamines.