Application of sperm motion kinematics and motility-related proteins for prediction of male fertility.

Overview

• This study aimed to identify new biomarkers related to sperm movement and specific proteins to better predict male fertility in Duroc boars, ultimately improving livestock breeding outcomes.

Introduction and Background

• Selection of high-quality male breeders (sires) is crucial for efficient animal production in the livestock industry.
• Traditional semen quality assessments rely on conventional analysis methods, which may lack precision in predicting fertility.
• Current biomarkers for male fertility prediction have limited effectiveness, highlighting the need for advanced physiological indicators.
• The study focuses on sperm motion kinematics—quantitative measures of sperm movement—and proteins associated with sperm motility as potential new biomarkers.

Research Objectives

• Evaluate sperm motion kinematic parameters and protein expression levels related to sperm motility in 30 Duroc boars.
• Assess the correlation between these parameters, protein levels, and actual fertility outcomes measured by litter size.
• Develop predictive models for male fertility using these new biomarkers.

Methods

• Selected 30 Duroc boars for analysis.
• Measured sperm motion kinematic parameters including:
  • Progressive sperm motility (%): Percentage of sperm moving actively forward.
  • Rapid sperm motility (%): Percentage of fast-moving sperm.
  • Slow sperm motility (%): Percentage of slow-moving sperm.
  • Straight-line velocity (μm/s): Speed of sperm moving in a straight line.
  • Linearity (%): Degree to which sperm swim in straight trajectories.
  • Beat cross frequency (Hz): Frequency of flagellar beat crossing the sperm’s central axis.
  • Mean angular displacement (degree): Average turning angle during sperm movement.
  • Wobble (%): Variation in sperm head side to side movement.
• Measured expression of motility-related proteins, specifically axonemal dynein light intermediate polypeptide 1 (DNALI1) and radial spoke head protein 9 homolog (RSPH9).
• Analyzed correlations between all measured parameters and actual litter sizes produced by the boars.

Key Findings

• Several sperm motion kinematic parameters showed strong correlation with litter size, indicating a relationship between sperm motility characteristics and fertility.
• Expression levels of DNALI1 and RSPH9 proteins significantly correlated with litter size, suggesting these proteins play important roles in sperm motility linked to fertility.
• Predictive models using sperm motility parameters and protein levels achieved over 60% accuracy in predicting litter size outcomes.
• Applying the prediction model in practice corresponded to an observed increase in litter size, highlighting practical benefits.

Implications and Conclusions

• This study identifies sperm motion kinematic parameters and levels of specific motility-related proteins as potential new biomarkers for assessing male fertility.
• DNALI1 and RSPH9 proteins, in particular, are promising targets for future research and practical fertility prediction tools.
• Improved biomarker identification can enhance breeding programs by selecting boars with higher fertility, boosting efficiency and productivity in livestock production.
• Understanding these parameters also contributes to the biological knowledge of sperm motility mechanisms, potentially benefiting human and animal reproductive health fields.

Summary

• By integrating sperm movement characteristics and protein expression data, the research improves fertility prediction accuracy beyond conventional analysis techniques.
• The findings may pave the way for advanced semen evaluation methods to optimize breeding strategies and outcomes in the livestock industry.