Scientists have created synthetic human embryos using stem cells, in a groundbreaking advance that sidesteps the need for eggs or sperm.
Scientists say these model embryos, which resemble those in the earliest stages of human development, could provide a crucial window on the impact of genetic disorders and the biological causes of recurrent miscarriage.
However, the work also raises serious ethical and legal issues as the lab-grown entities fall outside current legislation in the UK and most other countries.
The structures do not have a beating heart or the beginnings of a brain, but include cells that would typically go on to form the placenta, yolk sac and the embryo itself.
Prof Magdalena ?ernicka-Goetz, of the University of Cambridge and the California Institute of Technology, described the work in a plenary address on Wednesday at the International Society for Stem Cell Research’s annual meeting in Boston.
“We can create human embryo-like models by the reprogramming of [embryonic stem] cells,” she told the meeting.
There is no near-term prospect of the synthetic embryos being used clinically. It would be illegal to implant them into a patient’s womb, and it is not yet clear whether these structures have the potential to continue maturing beyond the earliest stages of development.