A symbolic step has just been taken in embryo research. Some will speak of a risk of “transgression” or “blurring of borders” between the human species and other animal species. Others will highlight the prospects for scientific and biomedical progress opened up by this work. Two teams, one French, the other Chinese-American, have succeeded in creating chimeric monkey-man embryos. More precisely, they introduced human cells into monkey embryos, which were then cultured in the laboratory for three days (for the French team) or ten to nineteen days (for the Sino-American team). The first study was published on January 12, 2021 in review Stem cell reports. The second, April 15 in review Cell.
This work raises a series of questions. What are the expected benefits? What are the risks? And what are the ethical issues? “This research is not intended to do anything and everything. We are very aware of their biomedical but also ethical issues ”, assures Pierre Savatier, from Inserm in Lyon, who coordinated the French study. What does Swiss law say? It prohibits the making of chimeras. But according to article 2 of the law on medically assisted procreation, an embryo-chimera is defined as “the union of pluripotent cells originating from two or more genetically different embryos”. However, the human cells used to produce the chimeric embryos, in these two studies, do not come from human embryos. “These experiments would not therefore be prohibited in Switzerland”, notes Professor Samia Hurst, director of the Institute of Ethics History Humanities at the University of Geneva.