Oxidative stress is involved in age-dependent spermatogenic damage of Immp2l mutant mice

► Oxidative stress increases in old Immp2l mutant mice with impaired spermatogenesis. ► Apoptosis is increased in round spermatids, 2N cells, and spermatocytes. ► Testicular cytosolic GPX4 decreases in mutant mice with impaired spermatogenesis. ► Mitochondrial DNA mutation is not involved in impaired spermatogenesis of mutants.