The functionality of mitochondria differentiates human spermatozoa with high and low fertilizing capability

By using flow-cytometric sorting, we compared some of the major factors related to fertility in sperm subpopulations with high and low mitochondrial membrane potential (ΔΨm). Results demonstrate that ΔΨmhigh spermatozoa represents a subpopulation of sperm with high fertility performance because they have normal morphology, high motility values, and calcium ionophore–induced acrosome reaction, suggesting the importance of mitochondrial functionality for fertilizing capacity of human spermatozoa.