Quantitative Phosphoproteomics Analyses Reveal the Regulatiory Mechanisms Related to Frozen-thawed Sperm Capacitation and Acrosome Reaction in Yak (Bos grunniens)

Mammalian spermatozoa are not utterly mature after ejaculation and must undergo additional functional and structural changes within female reproductive tracts to achieve subsequent fertilization, including both capacitation and acrosome reaction (AR), which are dominated by post-translational modifications (PTMs), especially phosphorylation. However, the mechanisms of protein phosphorylation during frozen-thawed sperm capacitation and AR has not yet been well studied. We employed phosphoproteomic approach based on TMT labeling combined with LC-MS/MS strategy to analyze frozen-thawed sperm in Ashidan yak under three sequential conditions (density gradient centrifugation-based purification, incubation in the capacitation medium and induction of AR processes by the calcium ionophore A23187 treatment).