Mice were treated with vehicle (Control), HN, HNG-F6A (Humanin-S14G-F6A), CP, CP+HN or CP+HNG-F6A as described in experimental procedures (n=4 each group). HN or HNG-F6A alone did not change apoptosis compared with control. Compared with control, CP increased germ cell apoptosis both in early+late (I–IV and XI–XII) and middle (VII–VIII) stages. HN significantly suppressed CP-induced apoptosis in early+late stages but not in middle stages. HNG-F6A prevented CP-induce apoptosis both in early+late and middle stages remarkably. Values are means ± SEM. Means with unlike superscripts are significantly (P<0.05) different.