<p>Testicular sections from wt (A-D) and TMF<sup>-/-</sup> mice (E-F) were subjected to EM analyses. (A) Stage 2/early 3 wt spermatid. (B) Boxed area in <b>A</b> under higher magnification. The acroplaxome is marked by arrows. (C) Stage 4 wt spermatid. (D) The boxed area in <b>C</b> under higher magnification. The acroplaxome is marked by arrows. (E) Stage 4 TMF<sup>-/-</sup> spermatid. (F) The boxed area in <b>E</b> under higher magnification. The supposed localization of the acroplaxome is marked by arrows. Ac = acrosome, Nu = Nucleus. Bars represent 2μm (A, C and E) and 1μm (B, D and F). Each image represents one out of twenty different cells selected from three different sections which gave similar results. Immunocytochemical staining of F-actin (red) and acrosome (green) in round spermatids from wt (G-I) and TMF<sup>-/-</sup> (J-L) mice, which were exposed to hypotonic shock.DIC images of the stained spermatids are shown in <b>I</b> and <b>L</b>. Acroplaxome margins are marked by arrows in <b>G</b>. (M) Immunocytochemical staining of F-actin (red) in wt round spermatid. (N) Immunocytochemical staining of F-actin (red) in TMF<sup>-/-</sup> round spermatid. (O) Immunocytochemical staining of F-actin (red) and TMF (Green) in wt round spermatid. (P) Immunocytochemical staining of F-actin (red) in wt elongated spermatid. (Q) Immunocytochemical staining of F-actin (red) in TMF<sup>-/-</sup> elongated spermatid. DIC images of the spermatids are also shown in <b>P</b> and <b>Q</b>. Nuclei were visualized with Hoechst solution (blue). Bars represent 10μm. Images represent one out of five independently prepared cell suspensions that gave similar staining profiles.</p