Scientists have announced a major breakthrough after successfully turning human skin cells into eggs and fertilising them with sperm in the laboratory for the first time.
The US-led research team cautioned that the technology, known as in-vitro gametogenesis, is still many years away from clinical use. However, experts say it could redefine infertility, which currently affects one in six people worldwide.
“If successful, this approach could allow older women or women who lack eggs for other reasons to genetically reproduce,” explained Paula Amato, co-author of the study from the Oregon Health & Science University. “It also would allow same-sex couples to have a child genetically related to both partners.”
The study, published in Nature Communications, involved removing the nucleus from normal skin cells and transferring it into donor eggs that had been stripped of their own nuclei — a process similar to the one used to clone Dolly the sheep in 1996. To address the challenge of excess chromosomes, researchers applied a new method called “mitomeiosis,” enabling the cells to mimic natural division.
From this process, 82 developing eggs (oocytes) were created and later fertilised through in vitro fertilisation. After six days, fewer than nine per cent of embryos developed to a stage comparable to those used in IVF. However, abnormalities were detected, prompting scientists to end the experiment.
While the success rate was low, the researchers noted that in natural reproduction, only about one-third of embryos typically reach the blastocyst stage suitable for IVF.
Amato estimated it may take at least a decade before the technology becomes viable. “The biggest hurdle is trying to achieve genetically normal eggs with the correct number and complement of chromosomes,” she said.
Ying Cheong, a reproductive medicine researcher at the University of Southampton, described the findings as “exciting.” She noted: “For the first time, scientists have shown that DNA from ordinary body cells can be placed into an egg, activated, and made to halve its chromosomes, mimicking the steps that normally create eggs and sperm. This could transform our understanding of infertility and miscarriage.”
Other laboratories are experimenting with alternative methods, such as turning skin cells into induced pluripotent stem cells before reprogramming them into eggs. Amato said it remains too early to determine which technique will ultimately prove most effective.
The researchers emphasised that their work adhered to existing US ethical guidelines regulating embryo research.
