Sperm Proteome: What Is on the Horizon?

As the mammalian spermatozoa transcends from the testis to the end of the epididymal tubule, the functionally incompetent spermatozoa acquires its fertilizing capability. Molecular changes in the spermatozoa at the posttesticular level concern qualitative and quantitative modifications of proteins along with their sugar moieties and membranous lipids mostly associated with motility, egg binding, and penetration processes. Proteomic studies have identified numerous sperm-specific proteins, and recent reports have provided a further understanding of their function with respect to male fertility. High-throughput techniques such as mass spectrometry have shown drastic potential for the identification and study of sperm proteins. In fact, compelling evidence has provided that proteins are critically important in cellular remodeling event and that aberrant expression is associated with pronounced defects in sperm function. This review highlights the posttesticular functional transformation in the epididymis and female reproductive tract with due emphasis on proteomics.