Scientists create viable human eggs from skin cells
Researchers at Oregon Health and Science University have successfully generated functional human egg cells from skin cells, which were then fertilized in the lab to produce early-stage embryos. This breakthrough, published in Nature, represents the first time such eggs have been matured and used for fertilization outside the body. The technique could eventually aid infertility treatments and genetic disease prevention.
In a landmark study, a team led by Shoukhrat Mitalipov at Oregon Health and Science University (OHSU) transformed ordinary skin cells into immature egg precursors, known as primordial germ cell-like cells (PGCLCs). These were derived from induced pluripotent stem cells (iPSCs), which are reprogrammed adult cells capable of developing into various cell types. The process, detailed in a paper published in Nature on March 13, 2024, involved maturing the PGCLCs into oocytes in a lab dish before fertilizing them with sperm from a donor.
The resulting embryos developed into blastocysts, the stage at which they typically implant in the uterus. 'This is the first time that human oocytes derived from skin cells have been matured and fertilized,' Mitalipov told Wired. The experiment used skin cells from female donors, ensuring the eggs carried the donor's DNA. No animals were involved in the human cell maturation, a departure from previous mouse studies where similar techniques produced healthy pups.
Background on the research traces back to earlier work with animal models. In 2016, Japanese scientists created viable mouse eggs from skin cells, leading to live births. Mitalipov's team built on this by adapting the method for human cells, overcoming challenges like the complexity of human reproduction. The study involved 25 skin cell lines from three female donors aged 18 to 30, producing over 100 PGCLCs per line.
While promising, the technique is not yet ready for clinical use. Only a small number of the fertilized eggs reached the blastocyst stage, and further testing is needed for safety and efficiency. Ethicists have raised concerns about potential misuse, such as creating designer babies, though the researchers emphasize therapeutic applications. 'Our goal is to help people who can't have children due to the loss of eggs,' Mitalipov said in New Scientist.
This advance could transform reproductive medicine, offering hope for women with ovarian failure or those undergoing cancer treatments that destroy eggs. It might also enable the creation of eggs from male skin cells in the future, pending ethical approvals, broadening options for same-sex couples or single men. However, regulatory hurdles remain, with experts calling for international guidelines to govern such stem cell research.