Effect of Transport Condition on the Structural Integrity of Ovarian Tissue and the Development of Sheep Embryos In-Vitro

Abstract

The oocyte quality decreases during ovarian tissue transport to the laboratories of in vitro embryo production. To provide additional information on how the conditions of transporting sheep ovaries impact the ovarian tissue and oocytes’ ability to develop into blastocyst stages, we have studied new transport media Ankara University Zootekni (AUZ1, AUZ2) supplemented with antioxidants (melatonin, Vit E, and Vit A), buffer solution, and energy substrates, and compared them with the traditional transport media: Phosphate-Buffered Saline (PBS), and Charles Rosenkrans 1 (CR1), Normal Saline (NS) at different temperatures (-6 to 30 °C). We also studied and compared how well different transport media preserve the ovarian tissue's structural integrity while transporting sheep ovaries at 4°C. Our findings indicated that various temperatures and transport media play critical roles in embryo development. The embryo development rates showed that when sheep ovaries are transported in AUZ1, they produce oocytes with a higher embryo development rate than other transport media at any temperature. In addition, histology examination revealed that the transport of sheep ovarian tissue in any medium at a temperature of 4 °C did not negatively impact the viability and histomorphology of the primordial, primary, and secondary follicles. In contrast to other transport media, the AUZ1 medium maintained the normal morphology of antral follicles, Graafian follicles, and the cumulus oophorus of sheep ovarian tissue. In conclusion, adding melatonin, buffer solution, and energy substrates to the transportation medium of ovarian tissues has a beneficial and positive role in maintaining ovarian tissue and increasing the rates of embryonic development.