Alpha-Lipoic acid supplementation during in vitro culture of abattoir- and OPU-derived bovine oocytes improves embryonic quality.

The Ovum Pick-Up (OPU) technique offers a rapid path to genetic improvement. Embryonic genome activation (EGA) is crucial for successful embryonic development and occurs in two phases: minor EGA (MN _EGA ) from 2-cell to 8-cell stages, and major EGA (MJ _EGA ) from 8-cell to 16-cell stages. Supplementation with alpha-lipoic acid (ALA) during MN _EGA using abattoir derived-oocytes has been shown to enhance in vitro embryo production. Two experiments were carried out in the study at hand. Experiment I aimed to evaluate ALA effects on embryo development and quality during MJ _EGA using abattoir-derived oocytes. Oocytes were treated with either a Control in vitro culture (IVC) medium or 2.5 µM ALA during MJ _EGA . The ALA presented a trend to increase the blastocyst cell number on day 7 (P = 0.06), along with reducing ROS levels and increasing GSH levels (P ≤ 0.05). Experiment II aimed to verify whether the results from abattoir- derived oocytes could be extrapolated to OPU-derived oocytes. The treatments included a Control, 2.5 µM ALA during MN _EGA , and 2.5 µM ALA during MJ _EGA . The ALA supplementation during MJ _EGA improved the total blastocyst rate on day 8 (P = 0.04), with a trend towards increased blastocyst cell number on day 7 (P = 0.09). No improvements were observed in MN _EGA . Overall, ALA supplementation during MJ _EGA is more effective than during MN _EGA for improving the embryonic quality of OPU-derived oocytes.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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