Revolutionary Breakthrough: Scientists Convert Human Skin Cells into Fertilizable Eggs for the First Time

Scientists have achieved a groundbreaking milestone by successfully converting human skin cells into eggs and fertilizing them with sperm in laboratory conditions, marking the first such accomplishment in medical history.

This revolutionary development could potentially enable infertile individuals to have biological children in the future, though the US-led research team emphasizes that practical applications remain years away from clinical implementation.

Independent experts note that this proof-of-concept research might eventually transform our understanding of infertility, a condition affecting approximately one-sixth of the global population.

Paula Amato, co-author of the study published in Nature Communications, explained to AFP that this technology, known as in-vitro gametogenesis (IVG), could benefit older women or those lacking eggs due to various medical conditions, allowing them to reproduce genetically.

"It also would allow same-sex couples to have a child genetically related to both partners," Amato added. She works as a researcher at Oregon Health & Science University in the United States.

This advancement follows significant progress in the field, including the July announcement by Japanese researchers who successfully created mice with two biological fathers.

The current study represents a major leap forward by utilizing human DNA rather than mouse cells. Researchers employed somatic cell nuclear transfer—the same technique used to clone Dolly the sheep in 1996—transferring nuclei from skin cells into donor eggs from which nuclei had been removed.

A key challenge was addressing the chromosome count: skin cells contain 46 chromosomes, whereas eggs have 23. The team developed a process called "mitomeiosis" to eliminate the extra chromosomes by mimicking natural cell division.

The scientists created 82 developing eggs (oocytes) and fertilized them through in vitro fertilization (IVF). After six days, less than nine percent of the resulting embryos reached the developmental stage potentially suitable for uterine transfer in a standard IVF procedure.

Despite displaying various abnormalities that led to the experiment's conclusion, researchers noted that even in natural reproduction, only about one-third of embryos develop to the "blastocyst" stage required for IVF readiness.

Amato estimates that widespread availability of this technology remains at least a decade away. "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 from the University of Southampton in the UK, described the development as an "exciting breakthrough."

"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 special steps that normally create eggs and sperm," Cheong explained.

"While this is still very early laboratory work, in the future it 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."

Alternative approaches are also being pursued by other researchers, who are reprogramming skin cells into induced pluripotent stem cells—which can develop into any body cell type—before converting them into eggs.

"It's too early to tell which method will be more successful," Amato commented. "Either way, we are still many years away."

The research team adhered to existing US ethical guidelines governing embryo use throughout the study.