Profiling of seminal plasma proteins to identify the fertility of Simmental bull with low semen quality

Abstract

Objective: The present study analyzed the seminal plasma proteome and possible relationships between proteins and semen quality in azoospermic and normal Simmental bulls. Materials and Methods: Fresh semen plasma samples from the Lembang Artificial Insemination Center were used for this study, including one bull (76´ ejaculate) with very poor semen quality/ azoospermia (poor fresh semen/infertile; PFS) and three bulls with normal semen quality (normal fresh semen; NFS) for proteomic analysis using a pooled system (NFS-Stud) (60´ ejaculate). The only males obtained with very low quality or azoospermia (PFS) had sperm motility of <10% (one head). Bulls with azoospermic conditions produce fresh semen without sperm or with very little sperm concentration. A total of 109 proteins were identified in the seminal plasma of Simmental bulls analyzed using liquid chromatography-mass spectrometry. Bioinformatics analysis was used to explore total protein, expression, function, and protein mechanism in the seminal plasma of Simmental bulls. Results: The results showed that the seminal plasma proteins expressed in NFS bulls include ELSPBP1, SIL1, HSPA13, angiotensin-1 covering enzyme, and CRISP1. On the other hand, B2M, C3, CFB, venin-2, and cathepsin S contribute significantly to PFS. The NFS bull proteins play important roles in sperm capacitation, protein transport, sperm motility, spermatogenesis, immune toler¬ance, and fertilization, while the PFS proteins perform apoptotic and antigen pathway functions. Conclusion: There is an interaction between proteins in the seminal plasma of males with poor semen quality (PFS) and cases of infertility (azoospermia) that cause a decrease in sperm quality in PFS bulls.