Human embryos created without sperm or egg: A revolutionary scientific advance

A team of researchers at the Weizmann Institute in Israel has just achieved an extraordinary scientific feat: the creation of complete models of human embryos without the use of sperm, eggs or a womb. Not only were these embryos created, they also managed to develop without a hitch.

This breakthrough marks a veritable revolution in the field of medical research. To achieve this remarkable result, the researchers used "pluripotent" stem cells, also known as "naive" cells. These cells have the particularity of not being predestined for a specific function and have the ability to transform into different types of cell. Some of these cells have been programmed to become the embryo, while others have been transformed into the placenta, the yolk sac and even the extra-embryonic membrane of the mesoderm, simply by activating specific genes.

Once assembled, these stem cells underwent an astonishing spontaneous self-organisation, evolving to form what can be called "embryo models". The researchers then observed these embryos develop perfectly smoothly over a period of 14 days, in line with the legal limit set for embryo research in 2021. At this stage, these small models measured around 0.5 mm and were made up of around 2,500 cells.

Although these results raise essential ethical questions, they also offer immense potential for broadening our understanding of the early stages of embryonic development, an area that is still largely unknown. What's more, this breakthrough could open the door to crucial new research into congenital diseases, infertility and many other medical fields.