Scientists have successfully created human eggs from skin cells, a breakthrough that could transform fertility treatment for women who cannot produce viable eggs and potentially for same-sex male couples. The research, led by Professor Shoukhrat Mitalipov at Oregon Health and Science University, is at an early stage but offers hope for genetically related offspring.
The technique uses somatic cell nuclear transfer, the same method used to clone Dolly the sheep. Skin cells from a woman are taken, and their nuclei are placed into donor eggs that have had their own nuclei removed. The major challenge was that healthy human eggs contain only 23 chromosomes, while skin cells have 46. After fertilisation with sperm, the scientists used a compound called roscovitine to prompt the eggs to expel half their chromosomes into a polar body, leaving the correct number to pair with sperm chromosomes.
However, the process resulted in random chromosome segregation and pairing, leading to abnormal chromosome numbers in early embryos. Out of 82 eggs created, fewer than 10% developed to the stage suitable for IVF transfer, and none survived beyond six days. The team acknowledges that further work is needed to improve efficiency and safety.
Professor Mitalipov described the work as a 'proof of concept' and estimated that perfecting the technique and demonstrating its safety could take another decade. He noted that skin cells from males could also be used, potentially allowing same-sex male couples to have genetically related children.
Other scientists praised the advance. Professor Richard Anderson of the University of Edinburgh said it could help women who have lost their eggs due to cancer treatment or other causes. Professor Ying Cheong of the University of Southampton highlighted the potential to transform understanding of infertility and miscarriage, while Professor Roger Sturmey of the University of Hull called the science 'impressive' but stressed the need for rigorous safety checks.
