Seminal plasma proteins and their relationship with sperm motility and morphology in boars

The identification of biomarkers associated with seminal traits could aid in the selection of higher quality ejaculates and benefit the swine industry. The objective of this study was to identify boar seminal plasma proteins associated with sperm motility and morphology. Twenty ejaculates from fifteen adult boars from a commercial boar stud were used for this work. After routine semen collection and analysis, ejaculates were classified into two groups: high-quality semen (HQS) and low-quality semen (LQS), based on sperm motility and morphology. Semen samples were processed for seminal plasma separation and analysis by 2D SDS-PAGE. Total and progressive sperm motility differed between groups (p < 0.001), as well sperm morphology (p < 0.05). The intensity of spots identified as Major seminal plasma PSP-I (PSP-I) and cathepsin B (CTSB) was higher in LQS as compared to HQS samples (p < 0.05). Also, PSP-I was positively associated with major and sperm cauda defects. Sperm motility was negatively correlated with both PSP-I and cathepsin B. We conclude that high concentrations of Major seminal plasma PSP-I and cathepsin B in boar seminal plasma are associated with reduced total and progressive sperm motility and low sperm morphology and might be used as biomarkers for semen quality.