US researchers have shown that it is possible to take stem cells from adult women and produce new human eggs in the laboratory.
The researchers looked for stem cells that have a specific protein called DDX4 on the surface.
These cells produce eggs in the ovaries of women at a reproductive age. In laboratory conditions, the cells spontaneously generated immature human eggs which matured when surrounded by ovarian tissue.
Due to legal and ethical restrictions on research into human eggs, the scientists were unable to test whether these eggs could be fertilised. However, the same method was tested in mice and the scientists were able to produce fertilised eggs and mice embryos.
It has long been thought that women are born with all the eggs they will ever have, but this study disproves the theory and researchers believe it opens up exciting new possibilities for new fertility treatments and technologies.
Dr Allan Pacey, from the University of Sheffield, said: “Not only does this re-write the rule book, it opens up a number of exciting possibilities for preserving the fertility of women undergoing treatment for cancer, or just maybe for women who are suffering infertility by extracting these cells and making her new eggs in the lab.”
Other researchers have backed the potential for new treatments, but they warn that stem cell fertility treatments are still a long way from any clinical use.