Sperm Motility and Viability: Overview of the Cellular and Physiological Aspects That Support These Functions

This review briefly summarises the cellular and physiological aspects of sperm motility (SM) and viability from the point of view of male fertility/infertility. We discuss the SM patterns and maturation processes during the epididymal transit, including the effects of seminal plasma proteins, and while moving through the female reproductive tract. In connection with SM and viability, the oxidative stress, the mitochondrial markers of SM and related predictive value of the proportion of motile sperm, and the effect of male age on sperm function are reviewed within the current literature. Furthermore, some of the potential techniques to determine molecules involved in sperm motion are presented. Other key points are sperm maturation and the markers of sperm maturity, including sperm-hyaluronic acid binding and DNA integrity, as well as the proportion of hyaluronic acid-bound sperm with respect to sperm morphology and tyrosine phosphorylation. Finally, proteins regulating SM and assessment approaches of sperm viability are pointed