Effect of sex sorting on stallion spermatozoa: Heterologous oocyte binding, tyrosine phosphorylation and acrosome reaction assay.

This research investigates the impact of sex sorting techniques on the bodily characteristics of stallion sperm. The techniques used include flow cytometry, and assessed factors are heterologous oocyte binding, acrosome reaction, and tyrosine phosphorylation. Experimental results suggest that sex-sorted stallion sperm are at a more advanced state of membrane destabilization, yet they retain similar binding ability to porcine oocytes.

Research Method

• The researchers utilized three different tests to examine the membrane status of sorted stallion sperm:
• The binding ability to porcine oocytes: Oocytes are the cells in an ovary which undergo genetic division to form an egg cell. This ability mears how well the sperm can attach to the female cell, which is critical for fertilization.
• Evaluation of acrosome integrity after stimulation with A23187: Acrosome is an organelle that develops over the anterior half of the head in the spermatozoa (sperm cell). A23187 is a mobile ion-carrier that forms stable complexes with most divalent cations. The acrosome’s reaction or release is a necessary step in the fertilization process.
• Detection of tyrosine phosphorylation: Phosphorylation is a process where a phosphate group is added to a protein to activate or deactivate it. Tyrosine phosphorylation is a type of protein modification that occurs in several vital cellular processes.
• The assessments were conducted post incubation for 0h, 1.5h and 3h in a capacitating medium. Capacitation is a process that sperm must undergo to have the ability to fertilize an egg.

Research Findings

• The study found out that sorted stallion sperm attached to porcine oocytes similarly to control samples.
• The sorted sperm showed a higher likelihood to undergo acrosome reaction initially, and after 1.5h and 3h of incubation.
• Moreover, they exhibited higher levels of tyrosine phosphorylation of the tail, but only at the beginning of the incubation period.

Conclusion

• The study concluded that stallion spermatozoa sorted by sex are in a more advanced state of membrane destabilization. This could indeed be related to the process of capacitation.
• However, the ability to bind similarly to oocytes observed in porcine samples is maintained, implying that sex sorting may not adversely impact the functionality of stallion sperm.