Journal of Reproduction and Development

1 Title 1 Resveratrol-induced mitochondrial synthesis and autophagy in oocytes derived from early antral 2 follicles of aged cows 3 Abstract 16 Mitochondrial numbers increase during oocyte growth. In this study, we collected oocytes and 17 granulosa cell complexes (OGCs) from early antral follicles (EAFs) of aged cows (> 120 months of 18 age) and examined the effects of resveratrol on mitochondrial generation, degradation, and quality in 19 oocytes grown in vitro. We also examined the effects of resveratrol on gene expression of the 20 granulosa cells. Resveratrol (20 µM) enhanced the expression of SIRT1 and induced autophagy in 21 both granulosa cells and oocytes derived from aged cows. Culturing the OGCs with resveratrol 22 increased mitochondrial DNA copy numbers in oocytes grown in vitro. Furthermore, resveratrol 23 increased the ATP content in oocytes and improved the developmental ability of the oocytes to the 24 blastocyst stage. Gene expression profiles in granulosa cells, as evaluated by next-generation 25 sequencing technology, revealed that resveratrol enhanced the expression of EIF2-related genes but 26 downregulated the expression of mammalian target of rapamycin (mTOR)-, inflammation-, and 27 cholesterol homeostasis-related genes in granulosa cells. In conclusion, resveratrol affected both 28 oocytes and granulosa cells derived from aged cows and improved the quality of oocytes grown in 29 vitro through upregulation of mitochondrial biogenesis and degradation in growing oocytes and 30 conditioning of granulosa cells. 31 32