Sperm cellular and nuclear dynamics associated with bull fertility

Area of Science:

• Animal Reproduction
• Sperm Biology
• Molecular Biology

Background:

• Sperm quality is crucial for livestock fertility.
• Protamine proteins (PRM1, PRM2) are vital for sperm chromatin condensation.
• Understanding protamine dynamics in relation to fertility is essential.

Purpose of the Study:

• To investigate cellular characteristics and protamine protein dynamics in Holstein bull sperm.
• To correlate sperm parameters and protamine abundance with bull fertility status.

Main Methods:

• Computer-assisted sperm analysis (CASA) for motility parameters.
• Flow cytometry assessed sperm membrane, acrosome status, DNA integrity, and protamine abundance.
• Sperm decondensation assay evaluated decondensation capacity.

Main Results:

• Sperm motility parameters differed significantly between high and low fertility bulls.
• No significant differences were observed in sperm membrane, acrosome, or DNA integrity.
• PRM1 and PRM2 abundances were inversely related and differed between fertility groups, impacting decondensation capacity.

Conclusions:

• Sperm protamine dynamics and abundance are key indicators of fertility in Holstein bulls.
• Molecular phenotypes of sperm, particularly protamine profiles, significantly influence livestock fertility.
• Further research into protamine's role can improve assisted reproductive technologies.