Proteomic profile of seminal plasma in tropical Saanen bucks under heat stress using 1D-SDS PAGE.

BACKGROUND

Tropical heat and humidity induce oxidative and thermal stress that threaten male fertility. However, the seminal plasma mechanisms that sustain sperm function under these conditions in goats remain poorly understood.

AIM: This study aimed to evaluate semen quality and characterize the seminal-plasma proteome of Saanen bucks raised under Indonesia's tropical conditions to identify molecular adaptations associated with fertility resilience.

METHODS

Three healthy bucks (five ejaculates each) were examined using computer-assisted sperm analysis (CASA) for sperm motility, viability, abnormality, membrane and acrosome integrity, and kinematics. Seminal-plasma proteins were separated by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and annotated through Gene Ontology enrichment.

RESULTS

While most semen traits and kinematics were comparable among bucks, abnormality and acrosome integrity differed significantly (p < 0.05). A conserved extracellular, vesicle-associated proteome was identified-including BSP1, BSP3, BSP5, ANXA5, ALB, HSPA1A, HSP90AA1, CLU, GPX5, and SOD1-with minor inter-individual variation in LTF, FN1, SPP1, and A2M. Enrichment (FDR < 0.05) highlighted the extracellular region, vesicle, and cytokine-regulatory pathways.

CONCLUSION

This study provides the first proteomic evidence of seminal plasma adaptation to THS in Saanen bucks, revealing a stable core of chaperone, antioxidant, and membrane-coating proteins that safeguard sperm function. These findings establish a novel proteomic basis for heat-resilient fertility and support the development of protein-based sire selection and reproductive management tools in tropical dairy-goat systems.