Circular RNAs as regulators and biomarkers of mammalian ovarian ageing

Ageing is a prevalent characteristic of all cells, tissues, and organs; certain ones, such as the ovaries, undergo significant ageing and do so early in the lifespan of mammals. Despite the widely recognized hormonal regulation occurring in the ovaries, numerous mechanisms influencing ovarian ageing remain unclear. Recently, a long-overlooked consequence of splicing, small RNA molecules, characterized by their circular structure, have gained attention. Circular RNAs (circRNAs) have been identified as products of gene transcription and are categorized among other non-coding molecules. The focus of researchers on circRNAs has been prompted by their remarkable capacity to influence the function of proteins, other RNAs, and genes. As further discoveries emerged, it became evident that these molecules were highly specific to particular tissues, with some being unique to significant physiological processes. The identification of their potential has enriched researchers' understanding regarding ovarian development and ageing, as several crucial connections to genes and ageing pathways have been revealed in current studies. This review article elucidates the significance of circRNA concerning the developmental competency and ageing of the ovary and suggests its potential as a biomarker for mammalian ovarian ageing.