Scientists have successfully created human eggs using skin cells, marking a groundbreaking step that could one day revolutionize fertility treatment.
In a study published in Nature Communications, researchers transplanted the nucleus of human skin cells into donor eggs that had been stripped of their own nuclei. This process produced 82 functional oocytes — immature egg cells — that were then fertilized in the laboratory.
Dr. Paula Amato, a coauthor of the study and professor of obstetrics and gynecology at Oregon Health and Science University, said the work demonstrates an important possibility for future treatments.
“This would allow older women, or women without eggs due to cancer treatment or other reasons, to have a genetically related child,” Amato explained. “In addition, it could potentially allow same-sex couples, such as two men, to have a child genetically related to both partners.”
The technique relied on a method the team called “mitomeiosis,” which mimics natural cell division to ensure eggs have the correct number of chromosomes. Typically, human sperm and eggs each contain 23 chromosomes, half the normal 46 found in other cells.
Despite this success, the study also revealed major hurdles. Fewer than 9% of the fertilized eggs reached the blastocyst stage — about five or six days of development — and all embryos showed chromosomal abnormalities.
Amato acknowledged the limitations, noting that the embryos would not have developed into healthy babies.
*They either had the wrong number of chromosomes or the wrong arrangement, so none would have resulted in viable pregnancies,” she said.
Experts not involved in the research have praised the study as a milestone, while stressing the need for caution.
Amander Clark, professor of molecular biology at UCLA, described the study as “an impressive advancement” but emphasized that it is not yet suitable for clinical use.
“All the embryos were genetically abnormal. Therefore, this approach will not, and should not, be offered in IVF labs until significant improvements are made,” Clark said.
Still, Clark noted its potential for women with ovarian failure, saying it represents “an important beginning.”
The method used — somatic cell nuclear transfer — was the same technique employed to clone Dolly the sheep in 1997. Unlike cloning, however, the process in this study involved genetic material from two individuals. Regulatory challenges are likely to slow any clinical rollout.
Ying Cheong, professor of reproductive medicine at the University of Southampton, called the findings “an exciting proof of concept.”
*While this is very early work, in the future it could transform how we understand infertility and miscarriage,” Cheong said. “It may one day lead to creating egg- or sperm-like cells for those who currently have no options.”
