Race for the first artificial embryos

“The first artificially created human embryo” – at first there was nothing more than a headline. But more backgrounds are now known. And they raise big ethical questions.

It was only a matter of time: Just a year ago, two competing research groups succeeded in creating artificial mouse embryos. Transferring this technology to human cells was the next logical step. The only question was: who would succeed first? A veritable race has broken out in biomedical research.

At a conference in Boston, American developmental biologist Magdalena Zernica-Goetz explained that she and her team had done just that: They had created a model of the human embryo from stem cells. There was no verifiable data yet, but after the media reported it, the public excitement was great.

competing teams Publish data

A few days later, a rival team from Israel uploaded such teams Results on a prepress server High: They also transferred their mouse findings into human cells and produced embryo-like structures. Other international groups followed, and eventually that too was published US team data.

Even if none of the published studies have been reviewed by independent experts yet, experts are talking about a breakthrough.

Stem cells instead of fertilized egg cells

In order to create the model embryos, the researchers didn’t need an egg cell, sperm, or fertilization. Instead, they manipulated human cells in the lab so that they regressed — into so-called stem cells. A variety of cell types can then emerge from these primary cells. And: Stem cells can be induced to form an embryo in the laboratory. Or at least something that closely resembles a real 13- to 14-day-old human embryo.

Michelle Poigny describes this progress as a “radical turning point”. He is the head of the working group “Mouse Embryology” at the Max Planck Institute for Molecular Biomedicine in Münster. Because: “For the first time in research, egg cells are no longer needed to develop human embryos in the laboratory.” But is what was actually created an embryo? This is now under discussion.

Embryos are more strictly protected than stem cells

Because in Germany it is forbidden to conduct research on embryos. According to the law, an embryo is created by definition from a fertilized egg cell. So the artificial embryos would not be blocked from stem cells. So the researchers call them embryonic models, or embryo-like structures, in their publications.

But in addition to the linguistic, there are also ethical challenges related to science and society. “Are artificial embryos less protective than extra embryos resulting from fertility treatment, for example? ”

Nils Hoppe and Sarah Rutger of the Center for Ethics and Law in the Life Sciences at Hannover University pose this question in a joint statement. “We will have to reorient ourselves socially again.” The German embryo protection law does not keep pace with scientific progress, so it must be completely replaced by a new, more modern law.

The field of research in reproduction

But scientific progress also gives hope. Because there is still so much that is not known about human reproduction. And it’s surprisingly ineffective. About 60 percent of pregnancies are already lost in the first two weeks after fertilization, and pregnant women often don’t realize this.

Relatively little is known about the reasons for this. This is also due to the strict rules for searching for human fetuses. This is where artificial embryo models can be used.

I wish for Basic research

Jesse Venfleet, head of the Stem Cell Genesis Working Group at the Max Planck Institute for Molecular Cell Biology and Genetics (CBG) in Dresden, sees great potential: “The similarity in terms of cellular structure, architecture and organization is incredible.” Many important milestones in early human development will be passed.

But not all of them: “In particular, embryo-like structures don’t go through the blastocyst stage — the stage when a normal embryo implants itself in the uterus.” It is not yet known to what extent this will affect the developmental potential of the embryo-like structures, that is, whether they are capable of producing a healthy, fully formed embryo, Feinfleet says.

The embryo models presented will provide a unique opportunity to learn more about human pregnancies and why they often fail at crucial stages. “But it is important to understand both the similarities and differences between an embryo and its model.”