Spermatozoa and seminal plasma proteomics: Too many molecules, too few markers. The case of bovine and porcine semen

The study of the protein composition of semen (i.e., spermatozoa and seminal plasma) is not new. However, with development of proteomics technologies, our understanding of the roles of cellular and fluid proteins has expanded enormously. Today, several seminal proteins have already been suggested as biomarkers associated with semen traits (e.g., sperm motility and integrity) and fertility. Also, many others were associated with infertility, being identified in humans and do-mestic animals with poor semen quality (e.g., oligozoospermia) and fertility impairment. These proteins not only might explain the causes of fail in fertilization but also have potential as diagnostic tools, improving traditional semen analyses. However, despite characterization of thousands of seminal proteins, to date, few commercial kits based on protein biomarkers are available. In this article, not only the advances and advantages of semen proteomics will be discussed, but also limitations in its application in a commercial AI centre.