Immunological Approaches for Sexing Bovine Sperm: A Comprehensive Overview

Presently, sorting bovine sperm based on their sex has significant potential, as using sexed semen can minimize the production of excess male calves, easing the challenges of bull management. Bull semen contains approximately 50% X chromosome-bearing sperm and 50% Y chromosome-bearing sperm. The differences between these sperm types include size, weight, density, swimming speed, electrical surface charges, and protein composition. Sexed semen, which is enriched with either X or Y sperm, enables the production of offspring of a desired sex with 80–90% accuracy. This technology, developed by the USDA and patented as “Beltsville sperm sexing technology,” has been categorized under various subheadings in this review, focusing on immunological sperm sorting, proteomic profiling, biotechnological applications, and bioinformatics analysis. Immunological sperm sorting leverages the distinct proteins on the surface of X- and Y-bearing sperm. Identifying these proteins can enable the development of antibodies specific to X or Y sperm. Proteomic profiling has revealed numerous proteins differentially expressed in X and Y sperm, which could serve as markers for immunological sorting. Despite various studies, consistent success in immunological sperm sexing has been elusive. However, recent advancements in proteomic technology and bioinformatics offer promising avenues for the identification and separation of sex-specific proteins. This review delves into the history, current methods, and future directions of immunological sperm sorting, highlighting the importance of accurate protein identification and the potential of bioinformatics to enhance sperm sexing technologies.