Fertility-Related Proteomic Profiling Bull Spermatozoa Separated by Percoll

Infertility or subfertility of bovine spermatozoa may lead to disintegration of the breeding system and large economic losses. Recently, proteomics have identified candidates for the sperm fertility biomarkers, but no definite studies have clearly identified the relationship between the proteome and sperm fertility after proteomic study. Therefore, to determine the clinical value of the protein markers identified by proteomic study, we first compared the protein expression profiles of spermatozoa from high and low fertility bulls using 2-dimensional electrophoresis. We then investigated the relationship between protein expression and the fertility of individual bulls as assessed by Western blot analysis. Five proteins, enolase 1 (ENO1), ATP synthase H+ transporting mitochondrial F1 complex beta subunit, apoptosis-stimulating of p53 protein 2, alpha-2-HS-glycoprotein, and phospholipid hydroperoxide glutathione peroxide, were more highly represented in high fertility bulls, whereas three proteins, voltage dependent anion channel 2 (VDAC2), ropporin-1, and ubiquinol-cytochrome-c reductase complex core protein 2 (UQCRC2), were more highly represented in low fertility bulls. Among those proteins, ENO1, VDAC2, and UQCRC2 were significantly correlated with individual fertility. Therefore, these results suggest that concurrent comparisons between protein expression and other fertility assays may represent a good in vitro assay to determine sperm fertility.