Ovarian fragment sizes affect viability and morphology of preantral follicles during storage at 4°C.

The research article discusses an investigation into how the size of ovarian tissue fragments, and the length of storage time, impact the health and viability of preantral follicles in horse ovaries during transport at 4°C.

Objective of the Research

The study aimed to determine how fragment size of the ovarian tissue (like a whole ovary, biopsy size, and transplant size) during varying storage periods (0, 6, 12 and 24 hours) can affect the structural integrity of horse ovarian tissue when transported at 4°C. The researchers’ goal was to identify optimum conditions to increase the success rate of Ovarian Tissue Cryopreservation (OTC).

Methodology

• Ovaries from 18 young mares were obtained.
• The ovaries were either kept intact, or cut into biopsy or transplant sizes to simulate varying fragment sizes.
• All samples were stored at 4°C for up to 24 hours in an α-MEM-enriched solution.

Outcome Parameters

• The health and state of preantral follicles with regards to their morphology.
• The density of stromal cells.
• The level of DNA fragmentation.
• The mitochondrial membrane potential.

Results of the research

• The smallest fragments (biopsy size) retained the most morphologically normal preantral follicles after 24 hours.
• The mitochondrial membrane potential was lowest in the intact ovary samples throughout each time period.
• All fragment sizes showed increased DNA fragmentation as the storage duration increased.
• The medium-sized fragments (transplant size) showed increased stromal cell density during the cool temperature storage.

Conclusion

The research concludes that biopsy-sized fragments are ideal for maintaining follicle morphology during long storage periods. However, the specific storage requirements should be set based on the duration of transportation to ensure optimum outcomes when moving tissue between patient and reproduction centers or clinics.