Review 1 acrosin 1 acrosome reaction 1 apoptosis 1 asthenospermia 1 cell nucleus DNA 1 disorders of mitochondrial functions 1 dna mutational analysis 1 energy yield 1 fertilization 1 gene expression homoplasmy 1 human 1 male fertility 1 male infertility 1 mitochondrial DNA 1 mitochondrial dynamics 1 mitochondrial genome 1 mitochondrial membrane potential 1 oxidative stress 1 parameters 1 reactive oxygen metabolite 1 sperm 1 sperm capacitation 1 sperm mitochondria 1 sperm quality 1 spermatogenesis 1 spermatozoon motility 1