Scientists turn human skin cell DNA into functional eggs

Researchers at Oregon Health & Science University (OHSU) have successfully transformed DNA from human skin cells into functional eggs capable of producing early human embryos, marking a significant breakthrough in reproductive science. However, the study, published on September 30 in Nature Communications, cautions that the eggs are not yet viable for clinical use and require further research.

The new method offers hope for millions facing infertility due to the lack of viable eggs or sperm and could eventually allow same-sex couples to have children genetically related to both partners, said Paula Amato, professor of obstetrics and gynecology at OHSU and co-author of the study, Axios writes.

The research also holds potential for women of advanced maternal age or those unable to produce viable eggs due to cancer treatments or other causes, according to an OHSU statement.

The team’s approach involved cloning and fertilisation techniques pioneered in the cloning of Dolly the sheep in 1997. Researchers isolated the nucleus of a skin cell and implanted it into a donor egg stripped of its own nucleus. Unlike Dolly’s cloning, which involved one parent, this method resulted in embryos containing chromosomes from both parents.

Despite this achievement, the study revealed limitations. All the embryos exhibited chromosomal abnormalities, and only 9% of the 82 eggs developed six days after fertilisation—the stage when embryos are typically transferred for in vitro fertilization (IVF). None of the embryos were cultured beyond this point.

Senior study author Shoukhrat Mitalipov, director of the OHSU Center for Embryonic Cell and Gene Therapy, emphasized the significance of the accomplishment: researchers have "achieved something that was thought to be impossible."

Experts not involved in the study also weighed in. Ying Cheong, professor of reproductive medicine at the University of Southampton, described the work as an “exciting proof of concept” demonstrating that DNA from ordinary body cells can be placed into an egg, activated, and made to halve its chromosomes—mimicking the natural process of creating eggs and sperm.

This process, known as mitomeiosis, could "transform how we understand infertility and miscarriage, and perhaps one day open the door to creating egg- or sperm-like cells for those who have no other options."

Richard Anderson, professor of clinical reproductive science at the University of Edinburgh, called the ability to generate new eggs "a major advance," noting the study shows that genetic material from skin cells can produce egg-like cells with the correct number of chromosomes for fertilization and early embryo development.

While he acknowledged significant safety concerns remain, Anderson said the work is "a step towards helping many women have their own genetic children."

Looking ahead, the researchers anticipate "at least a decade of further research before the approach could be deemed safe or effective enough to advance to a clinical trial, even assuming such a trial would be permitted in the United States," according to the OHSU statement.

The study underscores the need for continued investigation to ensure both efficacy and safety before clinical application.

By Sabina Mammadli