Scientists Create Fertilizable Eggs from Human Skin Cells

Scientists have successfully transformed human skin cells into fertilizable eggs, marking a significant breakthrough in reproductive technology. This achievement, announced on March 15, 2024, could potentially provide new options for individuals facing infertility, which affects approximately one in six people worldwide. The research team, based in the United States, cautioned that while the study holds promise, it remains years away from practical application for aspiring parents.

Paula Amato, a researcher at the Oregon Health & Science University and co-author of the study, explained that this technology, known as in-vitro gametogenesis (IVG), could enable older women or those who lack viable eggs for various reasons to have children. “It also would allow same-sex couples to have a child genetically related to both partners,” she added.

Breakthrough Technique and Research Findings

The study, published in the journal Nature Communications, builds on previous advancements in reproductive science. Notably, Japanese researchers had earlier announced the creation of mice with two biological fathers in July 2023. However, this new research is particularly groundbreaking because it utilizes DNA from human cells rather than animal models.

The process began with scientists removing the nucleus from skin cells and transferring it into a donor egg cell that had its nucleus removed, a technique known as somatic cell nuclear transfer. This method was previously used in cloning the famous sheep, Dolly, in 1996. A key challenge was to reduce the 46 chromosomes present in skin cells to the 23 chromosomes typical of eggs. The researchers developed a strategy termed “mitomeiosis” to mimic the natural cell division process, enabling them to create 82 developing eggs, or oocytes.

These oocytes were then fertilized using in vitro fertilization (IVF) techniques. After six days, approximately nine percent of the embryos reached the blastocyst stage, the point at which they could theoretically be transferred to a uterus. Despite this achievement, the researchers noted that the embryos exhibited various abnormalities, prompting the conclusion of the experiment at that stage.

While the nine percent success rate is modest, Amato highlighted that natural reproduction typically sees only about one-third of embryos progress to the IVF-ready blastocyst stage. She estimates that it may take at least a decade for this technology to become widely available for clinical use. “The biggest hurdle is trying to achieve genetically normal eggs with the correct number and complement of chromosomes,” she stated.

Implications for Future Reproductive Options

The implications of this research extend beyond traditional fertility treatments. Ying Cheong, a reproductive medicine researcher at the University of Southampton, described the findings as “exciting.” She remarked, “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.”

This development could alter the landscape of infertility and miscarriage, potentially leading to the creation of egg or sperm-like cells for individuals with limited options. Other researchers are exploring different methods to create eggs in laboratory settings, such as reprogramming skin cells into induced pluripotent stem cells, which have the capability to develop into any cell type.

Amato acknowledged that it remains unclear which technique will prove more successful in the long run, emphasizing that both approaches necessitate further research and development before they can be deemed viable.

The research adhered to established ethical guidelines concerning embryo use in the United States, ensuring that the study was conducted responsibly while pushing the boundaries of reproductive science. As this promising area of research continues to evolve, it may one day offer hope to countless individuals seeking to build their families.