Abstract
It is well known that the function of granulosa cells (GCs) is closely related to follicular development, and FoxO1 and histone methylation have been implicated in follicular development. However, the specific mechanisms by which FoxO1 and histone methylation regulate follicular development are still largely unknown. To explore the specific mechanism of FoxO1 in regulating follicular development, in this study, we showed that the expression of FoxO1 in immature ovaries and small follicles was significantly higher than in mature ovaries and large follicles of sows, respectively. FoxO1 was found to inhibit the secretion of testosterone and proliferation of porcine GCs and promote the secretion of progesterone and apoptosis of porcine GCs. Furthermore, H3K27me3, as a transcriptional inhibitor, can inhibit the transcription of FoxO1. FoxO1 could promote the transcription of CYP1A1, and CYP1A1 was found to inhibit the proliferation and facilitate the ferroptosis of porcine GCs. Collectively, our results revealed that the H3K27me3-FoxO1-CYP1A1 pathway might participate in follicular development, and these findings could provide potential targets for improving follicular development in sows.