Sperm physiology and in vitro fertility outcomes rely on their basal metabolic activity

Abstract

Abstract Although looking into the sperm metabolome could help to estimate the reproductive performance, no study has investigated through which mechanisms might sperm metabolism influence fertility outcomes. In this context, the present work sought to interrogate the energy source preferred by pig sperm, as well as the relationship of energetic metabolism with sperm quality, function and in vitro fertilisation (IVF) outcomes. To this end, a targeted metabolomic approach was used to determine the levels of metabolites belonging to glycolysis, ketone bodies and polycarboxylic acids cycle. Here we show that high-quality sperm were associated to greater levels of glycolysis derived metabolites. Additionally, embryo development, but not oocyte fertilisation, was conditioned by sperm metabolic status. Specifically, glycolysis appeared to be the preferential catabolic pathway in sperm giving rise to greater IVF outcomes. This study shows that the basal metabolic activity of sperm influences their function, even beyond post-fertilisation events.