Figure 8. Detection of testicular apoptosis of the young and aged mice. (A) Caspase 3 was immunolocalized in Leydig cells (arrowhead) of the control group. (B, C) in both young and aged mutant mice showed overexpression of Caspase 3 in the seminiferous tubules and interstitium (arrowheads). (D) In the melatonin group, Caspase 3 immunostaining in seminiferous tubules showed a normal pattern of apoptosis (arrowhead). (E, H) The Hoechst immunofluorescent stain showed normal spermatogenic activity (arrowheads) in both the control and melatonin groups. (F, G) The spermatogenic cells of the young and aged mutant mice showed nuclear fragmentation, condensation, and hyperchromatasia (arrowhead, boxed areas).