Reproductive stage-dependent effects of additional cryoprotectant agents for the cryopreservation of stallion germ cells.

The research investigates the effectiveness of additional cryoprotectant in preserving germ cells from stallions at various reproductive stages. It concludes that Polyethylene glycol (PEG) used in conjunction with dimethyl sulfoxide (DMSO) can successfully preserve germ cells in post-pubertal stallions.

Research Methodology

• The researchers harvested testicular samples from pre-pubertal (1-1.5 years old, n=6) and post-pubertal (3-7 years old, n=5) stallions.
• The germ cells were extracted through a two-enzyme digestion procedure and then cryopreserved in minimal essential medium alpha. This contained 10% fetal bovine serum and 10% DMSO, with or without the addition of trehalose (at concentrations of 50, 100, or 200mM) or polyethylene glycol (PEG, at 2.5, 5, or 10%).
• The viability, cell population, and viable population of the germ cells were assessed after 1 and 3 months of cryopreservation.
• The post-preservation viability of germ cells in pre-pubertal stallions was additionally assessed using immunocytochemistry to check for the presence of UTF1-positive cells.

Findings and Conclusions

• As expected, the viability, overall cell population, and viable cell population significantly decreased after 1 and 3 months of cryopreservation.
• At the pre-pubertal stage, adding either trehalose or PEG to the DMSO had no observable effect on the viability, cell population, or the count of viable UTF1-positive germ cells either 1 or 3 months post-cryopreservation.
• For post-pubertal stallions, adding 5% or 10% PEG to the preservation mixture yielded significantly higher viable cell populations compared to using 10% DMSO alone.
• The study concludes that using PEG, at a concentration of 5% or 10%, in combination with 10% DMSO, serves as an optimum cryoprotectant agent for preserving germ cells in post-pubertal stallions.