Positive effects of trehalose and cysteine on ram sperm parameters

Abstract

ABSTRACT:The aim of this study was to determine the effects of trehalose and cysteine on sperm motility, viability, mitochondrial activity and acrosome integrity during liquid storage of Merino ram semen. Ejaculates were collected using artificial vaginas from five Merino rams, microscopically evaluated and pooled at 37 °C. The pooled semen samples were diluted in a Tris-based extender, including cysteine (2 mM and 4 mM), trehalose (10 mM and 25 mM) and no antioxidant (control). Diluted semen samples were kept in tubes and cooled from 37 to 5 °C in a cold cabinet, and maintained at 5 °C. Cooled samples were evaluated for sperm motility, viability, mitochondrial activity and acrosome integrity at 0, 24, 48, 72 and 96 h. Extender supplemented with trehalose (10 and 25 mM) and cysteine (2 and 4 mM) led to higher motility in comparison to the control at 24, 48, 72 and 96 h of liquid storage (P < 0.05). Trehalose at the doses of 10 mM, 25 mM and 2 mM cysteine led to higher viability between 24-48-72 h and at 96 h of liquid storage (P < 0.05). Further, 4 mM of cysteine improved sperm viability rates at 24 and 48 h of storage compared to the control group (P < 0.05), and resulted in improved acrosome integrity rates compared to the control group at 72 and 96 h of storage (P < 0.05). Extender supplemented with 10 and 25 mM trehalose at 24 and 72 h and 4 mM cysteine at 24 and 96 h of storage led to higher sperm mitochondrial activity rates when compared to the control group (P < 0.05). In conclusion, the findings of this study show that trehalose and cysteine provided significant protection to ram sperm parameters during liquid storage.

l-cysteine prolonged fresh boar semen qualities, but not for docosahexaenoic acid

“…Nevertheless, it is worth noting that too a high concentration of l-cysteine (5 mM and 10 mM) may have a detrimental effect on chilled boar semen quality. Similarly, Gungor et al (2017) also indicated that the addition of a higher concentration of cysteine (4 mM) could maintain the ram sperm quality during chilled storage for 48 h but the sperm viability was significantly decreased at 96 h of storage when compared to 2 mM cysteine. These findings might be due to the limitation of l-cysteine uptake by spermatozoa and the amount of ROS production during the liquid preservation period (Kaeoket et al 2010b).…”

Recent approaches in the use of antioxidants and proteomic modifications in ram semen preservation

“…Research has shown that cysteine has antioxidant properties by activating existing antioxidant mediators, thanks to its thiol group. Previous studies have demonstrated that adding cysteine to freezing media or semen extenders significantly enhanced the post‐thaw motility, viability, membrane integrity, and acrosome integrity of ram spermatozoa (Altomare et al, 2020; Çoyan et al, 2011; Gungor et al, 2017; Khalili et al, 2010). Additionally, the inclusion of cysteine in semen extenders has been found to improve individual motility and plasma membrane integrity, and significantly reduce the mitochondrial apoptosis occurrence and DNA fragmentation in Awassi ram semen (Saieed et al, 2019).…”