Van de Hoek Madeleine, Rickard Jessica P, de Graaf Simon P
School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia.
Reprod Fertil Dev. 2026 Mar 10;38(4). doi: 10.1071/RD25174.
Mass motility assessment is widely used to evaluate semen quality in the sheep breeding industry, yet the biological factors influencing motility duration remain poorly characterised. At ejaculation, spermatozoa are combined with seminal plasma (SP), which initially supports motility and function but may compromise long-term metabolic endurance.
This study aimed to investigate the effects of SP on mass motility duration and pH regulation of epididymal ram spermatozoa.
Epididymal sperm were incubated with whole SP, saline, or left undiluted to assess motility duration. Subsequently, sperm were incubated with varying SP concentrations and molecular weight-separated fractions (protein-free <3 kDa; protein-enriched >3 kDa) and assessed for motility and pH over 24 h. Metabolomic and lipidomic profiling via targeted mass spectrometry characterised the biochemical composition of each SP fraction.
SP exposure significantly reduced mass motility duration (195 ± 11 min) compared with undiluted sperm (1797 ± 185 min; P = 0.0123) and saline dilution (2667 ± 134 min; P < 0.0001). All SP-treated groups exhibited a progressive pH decline, consistent with increased glycolytic flux, whereas SP-naïve sperm showed stable or increasing pH, indicating a more regulated metabolic state and greater metabolic flexibility. The protein-free SP fraction was most detrimental to motility, which was likely to be the result of the depletion of key proteins, lipids, and metabolites associated with energy production.
Prolonged exposure to SP impairs ram sperm motility longevity by promoting a glycolysis-biased metabolic state and reducing metabolic endurance.
Understanding how seminal plasma composition influences sperm metabolic regulation may inform strategies to better preserve sperm motility during semen handling and storage.
大规模活力评估在绵羊养殖业中被广泛用于评估精液质量，但影响活力持续时间的生物学因素仍未得到充分表征。射精时，精子与精浆（SP）结合，精浆最初支持精子活力和功能，但可能会损害其长期代谢耐力。
本研究旨在探讨精浆对附睾公羊精子大规模活力持续时间和pH调节的影响。
将附睾精子与全精浆、生理盐水孵育，或不稀释，以评估活力持续时间。随后，将精子与不同浓度的精浆和按分子量分离的组分（无蛋白<3 kDa；富含蛋白>3 kDa）孵育，并在24小时内评估其活力和pH值。通过靶向质谱进行代谢组学和脂质组学分析，表征每个精浆组分的生化组成。
与未稀释的精子（1797±185分钟；P = 0.0123）和生理盐水稀释组（2667±134分钟；P < 0.0001）相比，暴露于精浆显著缩短了大规模活力持续时间（195±11分钟）。所有经精浆处理的组均表现出pH值逐渐下降，这与糖酵解通量增加一致，而未接触精浆的精子pH值稳定或升高，表明其代谢状态更受调控，代谢灵活性更高。无蛋白的精浆组分对活力最具损害，这可能是与能量产生相关的关键蛋白质、脂质和代谢物耗竭的结果。
长时间暴露于精浆会通过促进以糖酵解为主导的代谢状态和降低代谢耐力，损害公羊精子活力的持久性。
了解精浆成分如何影响精子代谢调节，可能为在精液处理和储存过程中更好地保持精子活力的策略提供依据。
