N2B27 supports porcine parthenogenetic embryo development by improving redox and mitochondrial function

Porcine in vitro embryo production often relies on serum-supplemented media, yet fetal bovine serum (FBS) is chemically undefined and introduces batch-to-batch variability. Here, we tested whether the relatively defined N2B27 formulation improves porcine parthenogenetic embryo development compared with FBS-containing culture media and whether any developmental effects are associated with coordinated changes in oxidative stress, mitochondrial status, and apoptosis. After parthenogenetic activation, embryos were cultured in PZM-3 to the morula stage (96 h) and then transferred to PZM-3 (PZM), PZM-3 supplemented with 10% (v/v) FBS (PZM + FBS), or N2B27 for an additional 72 h. At 168 h, we assessed intracellular ROS and mitochondrial superoxide, ΔΨm and biogenesis-related indices, and apoptosis. N2B27 significantly increased blastocyst formation and hatching rates compared with both PZM conditions. In parallel, N2B27-derived blastocysts exhibited markedly lower intracellular ROS (-66.0% vs PZM; -45.9% vs PZM + FBS) and mitochondrial superoxide, higher ΔΨm, and increased expression of PPARGC1A, POLG, and TFAM. Although the number of TUNEL-positive nuclei did not differ among groups, total cell numbers increased and the apoptotic index decreased (-70.5% vs PZM; -53.5% vs PZM + FBS). These findings support N2B27 as a defined alternative to FBS-supplemented culture for mechanistic and applied embryo production, in association with reduced oxidative stress, improved mitochondrial status/biogenesis-related signatures, and attenuated apoptosis.