Scientists make human embryos from stem cells

Researchers from the University of Cambridge and the California Institute of Technology succeeded in creating human embryos without eggs and sperm. These embryos resemble real embryos in the early stages of their development. Therefore, the scientific achievement raises serious ethical and legal questions at the same time.

Embryos have neither a brain nor a heart. But they already have cells that will later form the placenta-yolk sac. Science talks about a “milestone” and wants to use it to advance research into rare genetic diseases and miscarriages.

“It’s beautiful and made entirely from embryonic stem cells,” Magdalena Zernica-Goetz, a professor at the University of Cambridge, told the Guardian. She and her colleagues hope to be able to circumvent the 14-day rule by using artificial structures.

Accordingly, human embryos may not be cultured in the laboratory for longer than two weeks. Then, researchers have to wait: only much later can they understand the course of development based on scans of pregnancy and embryos donated for research.

The participating scientists said that the desire to understand this stage of embryonic development, which begins around day 14 and ends around day 28, was the main motivation for creating artificial human embryos.

There is no prospect of clinical use of artificial embryos in the near future. It would be illegal to transplant it into a patient’s uterus. In addition, it is not yet clear whether cell structures can grow beyond the earliest stages of development.

Since then, the scientific race to transfer this work to human models has been on. Several research teams have already succeeded in replicating the early stages of development in this way.