ABSTRACT
PURPOSE: The present study investigated the effects of docosahexaenoic acid (DHA) on the growth of bovine oocytes. METHODS: Oocytes and granulosa cell complexes (OGCs) were collected from early antral follicles (0.4-0.7 mm) on the surface of ovaries harvested from a slaughterhouse. The OGCs were cultured with 0, 1, and 10 µmol/L docosahexanoic acid (DHA) for 16 days. RESULTS: Antrum formation of the OGCs and the number of granulosa cells (GCs) surrounding the oocytes were comparable among groups, whereas supplementation of 0.1 µmol/L of DHA significantly improved oocyte growth. Oocytes grown with DHA had a higher fertilization rate, acetylation levels of H4K12, and ATP contents, as well as a lower lipid content compared with those grown without DHA. In addition, GCs surrounding OGCs grown with DHA had low lipid content compared with vehicle counterparts. Furthermore, when GCs were cultured in vitro, DHA increased ATP production, mitochondrial membrane potential, and reduced lipid content and levels of reactive oxygen species. RNA-seq of GCs revealed that DHA increased CPT1A expression levels and affect genes associated with focal adhesion, oxidative phosphorylation, and PI3K-AKT etc. CONCLUSION: The results suggest that DHA supplementation affects granulosa cell characteristics and supports oocyte growth in vitro.