Myristic acid promotes in vitro maturation and developmental competence of porcine oocytes

The present study examined how antral follicle size influences oocyte meiotic maturation and developmental competence from a metabolic perspective and explored strategies to improve the meiotic maturation and quality of oocytes derived from small antral follicles. Untargeted metabolomics revealed dynamic metabolic changes during porcine antral follicle development, with increased fatty acid synthesis and enhanced activities of related enzymes in oocytes from larger follicles. In vitro, myristic acid (MA) improved meiotic maturation (polar body extrusion, spindle morphology, chromosome dynamics) and survival of oocytes from small follicles by reducing Annexin V expression and ROS levels. MA also enhanced their developmental competence after parthenogenetic activation. Molecular and cytochemical analyses showed that MA altered the transcriptional profile, increased lipid storage, and boosted mitochondrial number and function. Finally, MA upregulated SIRT1, activated PPARα, and increased CPT2 expression, suggesting a potential mechanism underlying its effects on these oocytes.