Scientists say it’s the first time synthetic human embryos have been produced from stem cells, without the need for eggs or sperm. These structures represent the earliest stages of human development and could enable crucial research into disorders such as recurrent miscarriages and genetic diseases. But as the pace of scientific discoveries outpaces legislation, it seems inevitable that questions will arise about legal and ethical implications.
This development was reported by The Guardian following the announcement by Cambridge University and Caltech developmental biologist Professor Magdalena Żernicka-Goetz at the 2023 annual meeting of the International Society for Stem Cell Research. The findings have not yet been published in a peer-reviewed paper.
Synthetic structures appear to model the beginnings of human development. For example, they do not yet have a brain or heart, but contain the cells that will be needed to form a placenta, egg sac and embryo. The structures have grown slightly beyond the 14-day natural gestation equivalent for a human embryo in the womb, Żernicka-Goetz said at the conference. It is not yet clear whether it will be possible to let them mature further.
This work is not intended to make lab-raised babies real. Instead, it aims to unravel the mystery of a period of human development that scientists have not had the opportunity to research until now.
Current laws allow human embryos to be grown in a laboratory for a maximum of 14 days. There is a period when developmental biology research is not possible after this point, as scientists can only conduct research by examining pregnancy scans and donated embryos. It is hoped that synthetic embryo technology can help bridge this gap.
University of Queensland’s Dr. “The ability to recreate early human development events using stem cells in a dish is a remarkable breakthrough in cellular and reproductive technologies,” said Rodrigo Suarez. “It ranges from better understanding how it organizes it to elucidating the genetic and cellular requirements involved in early human development in health and disease.”
Ethical and legal barriers
Stem cell-derived embryos were also developed by Żernicka-Goetz’s group in mice and monkeys before, and many speculate that human embryos may not be far behind. However, crossing this scientific milestone also brings with it a host of ethical and legal hurdles. One of the most basic questions here is how similar these structures are to natural embryos.
Synthetic mouse embryo with brain and heart formation…Professor Robin Lovell-Badge, head of stem cell biology and developmental genetics at the Francis Crick Institute, told the Guardian: “If the whole point is that these models look very much like normal embryos, then in a way, they should be treated the same. They are not the same in law at the moment. “People are worried about this,” he said.
From Swinburne University of Technology, Dr. Evie Kendal said, “While it is not yet clear how these synthetic embryos can be developed or used in research, it is not currently possible to use human embryos in research considered too risky if it is found that they are not equivalent to human embryos or that it is possible to restrict their development so that they do not acquire human characteristics legally and ethically. “They could potentially be useful.”
Evidence from similar studies in animals is also unclear. When monkey synthetic embryos were implanted into female monkey wombs, most failed to attach successfully, and those that did did not develop into viable fetuses. Mouse synthetic embryos, on the other hand, have developed enough to begin forming a beating heart and brain before succumbing to defects.
In a conversation with the Guardian, Lovell-Badge stated that it is not clear whether there is a biological reason why these structures cannot develop beyond a certain point, or whether these problems are due to technical barriers that could theoretically be overcome.
29454
