Fig. 4. LETM2 is localized in spermatogenic cells and spermatozoa. (A) Frozen sections of rat testis were immunostained using anti-LETM2 antibody (a,b,e,f) and preimmune serum (c,d). Samples were also counterstained using SYTOX Green to visualize nuclear DNA (b,d,f). Scale bar, 30 µm. (B) Purified rat spermatozoa were immunostained using antibodies against LETM2 (a,b) and tubulin (b,d). Images containing the principle (P) and middle pieces (M) of spermatozoa are shown. Scale bar, 20 µm. (C) Vertical sections (a) and cross sections (b,c) of rat spermatozoa were immunogold-labeled using anti-LETM2 antibody and preimmune serum. Arrows indicate mitochondria. A, axoneme; ODF, outer dense fiber. Scale bar, 0.1 µm.