Researchers at OHSU have demonstrated a new technique to treat infertility by turning skin cells into oocytes, or eggs. Shown here, an image of an oocyte with a bright image of a skin cell nucleus before fertilization. Oregon Health & Science University
Researchers at Oregon Health & Science University have achieved a scientific first: transforming human skin cells into eggs that can be fertilized in the lab.
Their study, published Tuesday in Nature Communications, is the first demonstration showing that skin cells can be reprogrammed to form eggs capable of developing into early embryos.
The finding hints at a future where people who cannot produce eggs of their own might have new options for building a family. But scientists say work is an early proof of concept and remains far from medical use.
Dr. Paula Amato, professor of obstetrics and gynecology at OHSU and a co-author of the study, said the method could one day help women who no longer produce viable eggs due to age or medical treatments, and it may even allow same-sex couples to have children genetically related to both partners.
At the heart of the breakthrough is what OHSU scientists call “mitomeiosis” — a process that blends the two primary forms of cell division. Normally, body cells like skin cells carry a full set of 46 chromosomes, while eggs and sperm carry only 23 each so that when they combine, the resulting embryo has the correct total.
In the experiment, the scientists placed the nucleus of a skin cell inside a donor egg that had its own nucleus removed. The egg’s environment then pushed the skin cell nucleus to shed half its chromosomes — mimicking the natural process of making an egg. Those new eggs were then fertilized with sperm through in vitro fertilization.
“We achieved something that was thought to be impossible,” said Shoukhrat Mitalipov, the study’s senior author and director of OHSU’s Center for Embryonic Cell and Gene Therapy. “Nature gave us two methods, and we just developed a third.”
In all, the researchers produced 82 eggs, but most embryos stopped developing after just a few cell divisions and showed abnormal numbers of chromosomes. Only about 9% grew to the blastocyst stage — the point at which embryos are typically transferred in IVF.
In the experiment, none were developed further.
“Most, if not all of them, had chromosomal abnormalities,” said Amato, a co-author of the study. “They either had too many chromosomes or too few, or they had the wrong combination, so none of them would really result in healthy babies.”
Amato said the team is trying to figure out whether the chromosome errors found in the engineered embryos were due to mistakes in chromosome separation or incomplete reprogramming of the skin cell DNA.
She said these technical obstacles underscore just how little scientists know about meiosis — the natural process of making eggs.
“It happens all the time in the woman’s body, but we can’t actually see it happening, so it’s like this black box,” Amato said. “We know it works in nature, but we don’t fully understand how chromosomes pair and separate correctly. Now we’re trying to recapitulate that in vitro, and it’s incredibly challenging.”
Amato said solving those problems will require years of additional research, and eventually testing the approach in nonhuman primates before it could be attempted in people.
She said funding the research is also a challenge, since federal law prohibits the use of federal money for research involving the destruction of human embryos, leaving projects like this dependent on private philanthropy.
[SRC] https://www.oregonlive.com/health/2025/10/ohsu-researchers-create-human-eggs-from-skin-cells-pointing-to-new-frontier-in-fertility-treatment.html
