DNA Methylation in the Ovary and Uterus of Mammalian Animal Models: Implications for Reproductive Function.

DNA methylation is a key epigenetic modification that regulates gene expression and maintains genome stability, particularly in mammalian reproductive tissues. This review summarizes the current knowledge of DNA methylation and demethylation fluctuations with a specific focus on the regulation of ovarian development and uterine function during pregnancy. This modification primarily occurs at CpG-rich regions and is catalyzed by DNA methyltransferases (DNMTs): DNMT1 maintains existing patterns during replication, while DNMT3A and DNMT3B establish de novo methylation. Demethylation is mediated by ten-eleven translocation enzymes (TET1, TET2, and TET3), which oxidize 5-methylcytosine, ultimately replacing it with unmethylated cytosine. These processes play essential roles in folliculogenesis, oocyte maturation, steroidogenesis, and tissue-specific gene regulation. Understanding these epigenetic mechanisms provides important insights into veterinary medicine and offers potential applications in fertility preservation across diverse mammalian species. Consequently, further research is essential to elucidate the clinical implications of these epigenetic processes for improving reproductive health outcomes in animals.