Sperm sexing is an Assisted Reproductive Technology (ART) that involves the sorting of “X” and “Y” chromosome-bearing live sperm cells of semen samples. It is the method of splitting spermatozoa into two subpopulations of spermatozoa-bearing X-chromosome and Y-chromosome with higher than average concentrations (up to 90%) of either the ‘X’ or ‘Y’ sperm to produce offspring of the desired gender. Sperm sexing technology has 80-90 % accuracy.
The earliest record of historical development is of ancient Greek philosophers like Democritus, around 470–402 BC, who proposed that the right testicle produces males, whereas the left testicle produces females. Afterward many scientist researchers had tried to separate X and Y bearing spermatozoa with variable success rate on the basis of the major differences between the X and Y chromosomes include DNA content, size, motility, surface charges and cell surface antigens, including the albumin gradient procedure, identification of H-Y antigen, free-flow electrophoresis, swim-up procedure, percoll density gradient, volumetric difference, flow cytometry, laser ablation, immunological, and microfluidic based sperm sorting. But among all major breakthroughs in sperm sexing was production of live offspring from sex-sorted, living rabbit sperm using Hoechst 33342 stain at the USDA Beltsville research center group. The flow cytometry is the most successful methods of sperm sexing till date. TLR 7/8 receptor expressed by 50% of round spermatid encoding X chromosomes.
Fertility is generally 10 to 12 % low when using normal concentrations of sexed semen compared with the use of normal concentrations of conventional semen. The production of sexed semen in India is primarily carried out by Sexing Technology and ABS, with these two companies dominating the market. Currently, the sole commercially accessible validated technique for sperm sexing is flow cytometry; however, it is not without its drawbacks, including cost, speed, and the fertility of sorted semen. Advancements in sperm sexing technologies may reduce costs and improve sorting efficiency, making sexed semen more accessible to farmers. Standardization of alternative sperm sorting methods such as immunological, microfluidic, and Raman spectroscopy based techniques is essential to ensure consistent accuracy, sperm viability and scalability for practical use in bovine. Optimization of sperm sorting protocols to minimize cellular damage and improve post-sorting viability can significantly enhance conception rates under field conditions.
International Journal of Veterinary Sciences and Animal Husbandry
