Overview

• Qianshu Zhu’s team reported irregular H3K27me3, H3K4me3 and H3K9me3 signatures in oocytes and day-3 embryos from PCOS patients at the European Society of Human Reproduction and Embryology meeting.
• In vitro application of PRC2 inhibitors EED226 and valemetostat reduced abnormal H3K27me3 levels and partially restored normal gene expression in affected embryos.
• Approximately half of the aberrant H3K27me3 marks detected in day-3 embryos were already present in the original oocyte, suggesting maternal transmission of epigenetic signals.
• The study analysed samples from 133 PCOS patients and 95 non-PCOS controls using ultra-low-input sequencing to map epigenetic and transcriptional changes during early embryonic development.
• Researchers plan to knock down the histone demethylases Kdm6a and Kdm6b in mouse models to test whether correcting these marks can prevent PCOS-like traits in offspring.