Effect of thymosin on maturation of pig oocytes and quality of in vitro produced embryos

Thymosin (TMS) is a peptide hormone that has regenerative qualities. To date, the regenerative qualities of thymosin have been tested only on somatic cells and bovine oocytes. The objective of this study was to determine the effect of thymosin on the in vitro maturation of pig oocytes and on in vitro fertilization (IVF), which would be used to assess the quality of obtained embryos. Pig oocytes (n = 463) were matured in vitro to the Met II stage in medium supplemented with TMS. After IVF the zygotes were cultured in vitro until they reached the blastocyst stage. The number of cells and the level of nuclear DNA fragmentation were evaluated. The addition of TMS to the maturation medium resulted in a significant increase in the percentage of competent oocytes that, after fertilization, developed to the blastocyst stage. Moreover, supplementing the maturation medium with TMS had a positive effect on the quality of obtained blastocysts by limiting the occurrence of apoptosis.