An Overview of How Epigenetics, MicroRNA-21, and Endocrine Disrupting Compounds Affect Oocyte Maturation and Pre-Implantation Embryo Development.

Epigenetic regulation is pivotal in reproductive processes, such as oocyte maturation and pre-implantation embryonic development, and it impacts gene expression without altering DNA sequence through mechanisms including DNA methylation, histone modifications, and non-coding RNAs. Primarily, microRNA-21 is involved in meiotic progression, apoptosis, and cumulus cell function, which are necessary for oocyte competency. miR-21 dysregulation can lead to improper oocyte maturation and poor embryonic development, ultimately causing developmental defects. During pre-implantation embryonic development, DNA methylation and histone modifications contribute to cellular reprogramming, ensuring proper gene activation and repression. Environmentally, endocrine disruptors affect miR-21 expression, potentially disrupting pathways involved in reproductive health and developmental programming. Overall, this review explores the correlation between epigenetics, miRNA regulation, and environmental factors, emphasizing the intricacies of oocyte maturation and pre-implantation embryonic development. This highlights the need for additional mechanistic and translational research in reproductive epigenetics.