Cryopreservation Effects on Ram Sperm Ultrastructure

Area of Science:

• Veterinary Science
• Reproductive Biology
• Biotechnology

Background:

• Cryoprotective agents are vital for mitigating cryoinjury to spermatozoa.
• Understanding the ultrastructural effects of cryoprotectants is essential for optimizing sperm cryopreservation protocols.

Purpose of the Study:

• To evaluate the cryoprotective efficacy of glycerol, ethylene glycol, and their combinations with trehalose on ram spermatozoa.
• To assess the ultrastructural integrity of frozen-thawed ram spermatozoa using scanning transmission electron microscopy.

Main Methods:

• Konya Merino ram ejaculates were diluted in a tris-based extender with various cryoprotectant formulations (glycerol, ethylene glycol, trehalose combinations).
• Sperm samples were cooled, frozen in liquid nitrogen, thawed, and processed for scanning transmission electron microscopy.
• Ultrastructural damage and intact spermatozoa were quantified via electron microscopic examination.

Main Results:

• Spermatozoa treated with 5% ethylene glycol and 1.5% ethylene glycol + 100 mM trehalose exhibited significantly higher intactness (p < 0.05).
• These specific ethylene glycol-based formulations demonstrated superior cryoprotection compared to other tested groups.

Conclusions:

• 5% ethylene glycol and 1.5% ethylene glycol + 100 mM trehalose offer the highest protection for ram spermatozoa ultrastructure post-cryopreservation.
• These findings suggest optimal cryoprotectant strategies for preserving ram sperm morphology and function.