Preservation of the quality and fertility potential of post-thawed rooster sperm using MitoQ

Effect of Five Different Antioxidants on the Effectiveness of Goat Semen Cryopreservation

The effective combination of semen cryopreservation and artificial insemination has a positive effect on the conservation of germplasm resources, production and breeding, etc. However, during the process of semen cryopreservation, the sperm cells are very susceptible to different degrees of physical, chemical, and oxidative stress damage. Oxidative damage is the most important factor that reduces semen quality, which is affected by factors such as dilution equilibrium, change of osmotic pressure, cold shock, and enzyme action during the freezing-thawing process, which results in the aggregation of a large amount of reactive oxygen species (ROS) in sperm cells and affects the quality of semen after thawing. Therefore, the method of adding antioxidants to semen cryoprotective diluent is usually used to improve the effect of semen cryopreservation. The aim of this experiment was to investigate the effects of adding five antioxidants (GLP, Mito Q, NAC, SLS, and SDS) to semen cryoprotection diluent on the cryopreservation effect of semen from Saanen dairy goats. The optimal preservation concentrations were screened by detecting sperm viability, plasma membrane integrity, antioxidant capacity, and acrosomal enzyme activities after thawing, and the experimental results were as follows: the optimal concentrations of GLP, Mito Q, NAC, SLS, and SDS added to semen cryopreservation diluent at different concentrations were 0.8 mg/mL, 150 nmol/L, 0.6 mg/mL, 0.15 mg/ mL, 0.6 mg/mL, and 0.15 mg/mL. The optimal concentrations of the five antioxidants were added to the diluent and analyzed after 1 week of cryopreservation, and it was found that sperm viability, plasma membrane integrity, and mitochondrial activity were significantly enhanced after thawing compared with the control group (P < 0.05), and their antioxidant capacity was significantly enhanced (P < 0.05). Therefore, the addition of the above five antioxidants to goat sperm cryodilution solution had a better enhancement of sperm cryopreservation. This study provides a useful reference for exploring the improvement of goat semen cryoprotection effect.

The effects of MitoQ as a mitochondrial-targeted antioxidant in a plant-based extender on buck sperm quality parameters during cryopreservation

Sperm cryopreservation plays an important role in the artificial insemination (AI) industry of small ruminants. It, however the use of frozen-thawed goat semen is limited due to the insufficient number of sperm with good biological functions. Mitochondria are the most sensitive organelles to cryopreservation damage in sperm. This study was conducted to determine the effects of MitoQ, the mitochondrial-targeted antioxidant, in a plant-based extender on the quality parameters of Markhoz goat sperm after the freezing and thawing process. Semen samples were collected and diluted in the extender, divided into five equal aliquots and supplemented with 0, 1, 10, 100 and 1000 nM MitoQ and cryopreserved in liquid nitrogen. After thawing, sperm motility, membrane functionality, abnormal morphology, mitochondrial activity, acrosome integrity, lipid peroxidation (LPO), DNA fragmentation, reactive oxygen species (ROS) concentration, viability and apoptotic-like changes were measured. The use of 10 and 100 nM MitoQ resulted in higher (P≤0.05) total motility (TM), progressive motility (PM), viability, membrane functionality, mitochondrial activity, and acrosome integrity compared to the other groups. On the other hand, LPO, apoptotic-like changes, DNA fragmentation and ROS concentration were lower (P≤0.05) in MQ10 and MQ100 groups compared to the other groups. MitoQ has no effect (P>0.05) on sperm abnormal morphology and velocity parameters. In conclusion, MitoQ can reduce oxidative stress by regulating mitochondrial function during the cryopreservation process of buck sperm and could be an effective additive in the cryopreservation media to protect sperm quality.