Correlation between PRDX6 levels and freezability properties of sheep semen

Individual variations in the freezability properties of sheep semen may be related to the antioxidant levels of sperm. PRDX6 is a key antioxidant protein in sperm, but its relationship with the freezability properties of sheep semen remains unclear. This study, using Hu sheep as the research subject, investigated the levels of PRDX6 in sperm with different freezability properties. A positive correlation was found between the levels of PRDX6 and sperm freezability. Furthermore, when different concentrations of PRDX6 recombinant protein were added to high-freezing-resistant (HF) and low-freezing-resistant (LF) sperm, it was revealed that 20 μg/ml of PRDX6 recombinant protein significantly improved various sperm quality parameters in both HF and LF sperm and reduced the differences in sperm freezability properties. Finally, adding a PRDX6 peroxidase activity inhibitor (Ethacrynic acid) or a calcium - independent phospholipase A2 (iPLA2) activity inhibitor (MJ33) to the diluent significantly reduced the freezability parameters of sperm. This indicates that PRDX6 protects sperm from freezing damage through two pathways. In summary, this study reveals the crucial role of PRDX6 in the freezability properties of sheep semen. It suggests that increasing the levels of PRDX6 in sperm may be an effective strategy to improve the quality of cryopreserved semen. Future research can further explore the molecular mechanisms regulating the levels of PRDX6, providing a scientific basis for the optimization of sheep semen cryopreservation techniques.