New research from the University of Exeter has shown that the ovaries, including their tissue structure and cells, play a larger role in fertility decline than previously thought. Traditionally, it has been believed that the decrease in egg quality and number as women age was the main reason for fertility decline. However, this study has indicated that changes in the ovary’s tissues and cells may also significantly contribute to fertility decline. The research team used mice as their study model due to the similarities in ovarian biology between humans and mice. The team discovered that the tissue structure in ovaries differs between young and old individuals, and these changes could explain why human ovaries age earlier than other species. Additionally, the researchers genetically manipulated glial cells in mice, leading to a condition similar to Polycystic Ovarian Syndrome (PCOS) in humans. This discovery provides hope for future treatments for PCOS and other fertility-related conditions.