A study by the University of Wisconsin-Madison has unveiled new details on how women's fertility works. Researchers have identified two genes working together to establish cellular communications in the ovaries. In guinea pigs, the system helps keep the oocytes healthy and guarantee their survival. The discovery could explain some cases of unexplained infertility and early menopause.
In the early menopause the ovaries stop producing estrogen, causing premature loss of the oocytes. This condition affects about 3% of women, in many cases without obvious symptoms. Previous studies by Dr. Jorgensen had revealed a possible cause. In guinea pigs without the IRX3 and IRX5 genes, follicles worked less well. This resulted in a smaller number of children, which made one think of fertility problems.
Going forward, the studies have revealed that the two genes are expressed in two different areas of the ovaries. Nevertheless, they are both essential for synchronizing oocytes and granular cells. The two types of cells expand the membranes by creating the junctions between them. In this way they communicate and regulate themselves in view of fertilization. Without the two genes, the process stops and the follicles remain destabilized.
Despite the findings made on guinea pigs, researchers are still not sure whether they are applicable to humans. The next step will be to check this point, but further studies will be needed.