The new study, led by scientists at the Weizmann Institute of Science in Israel, builds on two strands of the group’s previous research. The first involved reprogramming stem cells into a “naive” state that allowed them to differentiate into all other cells, including other stem cells. Other work focused on developing a device that could grow embryos more efficiently outside of the womb.
Combining the two methods, the team started with naive mouse stem cells cultured in a petri dish for several years. They were divided into three groups whose key roles were identified in the development of the embryo.
One group included cells that would develop into embryonic organs. The other two were engineered with genes that regulate extra-embryonic tissues – the placenta for one group and the yolk for the other. The three cell types were then mixed in an artificial womb, which carefully controlled the pressure and oxygen exchange and gently mixed the contents to mimic natural nutrient flow.
Once inside, the three types of cells stuck together, forming aggregates that could potentially develop into embryonic structures. Of the approximately 10,000 embryos, only 50 successfully developed further.
This lucky few eventually began to form cell spheres, elongated structures resembling natural embryos, complete with a placenta and yolk sac. For more than eight days, mice were allowed to develop in almost half of the gestation period; During this time, they formed all early organ precursors, including a beating heart, circulating blood stem cells, a well-formed brain, and gut. path and primitive spine.
Upon closer inspection, the team found that the shape of the internal structures and the nature of gene expression of these synthetic embryos matched those of natural ones with 95% accuracy. His organs also appeared functional.
Source: Ferra
