Natural and synthetic embryos side by side with heart and head folds stained in color. Credit: M. Zernicka-Goetz
Key Points:
- After 10 years, researchers succeeded in creating model mouse embryos from stem cells that have beating hearts, as well as the foundations for a brain.
- A major advance in this study is the ability to generate the entire brain, in particular the anterior region.
- The results could also be used to guide repair and development of synthetic human organs for transplantation.
Researchers from the University of Cambridge and Caltech have created model mouse embryos from stem cells that have beating hearts, as well as the foundations for a brain and all of the other organs in the mouse body.
This is the most advanced stage of development achieved to date in a stem cell-derived model.
The embryo model was developed without eggs or sperm. Instead, the researchers mimicked natural processes in the lab by guiding the three types of stem cells found in early mammalian development to the point where they start interacting.
Eventually, the stem cells “talked” to one another and self-organized into structures that progressed through the successive developmental stages until the synthetic embryos had beating hearts and the foundations for a brain, as well as the yolk sac where the embryo develops.
A major advance in this study is the ability to generate the entire brain, in particular the anterior region, which has eluded others in prior studies.
"This opens new possibilities to study the mechanisms of neurodevelopment in an experimental model," said study author Magdalena Zernicka-Goetz, professor of biology and biological engineering at Caltech. "It's just unbelievable that we've gotten this far. This has been the dream of our community for years, and the major focus of our work for a decade, and finally we've done it."
Over the past decade, Zernicka-Goetz's team has been studying these earliest stages of pregnancy to understand why some pregnancies fail and some succeed.
"The stem cell embryo model is important because it gives us accessibility to the developing structure at a stage that is normally hidden from us due to the implantation of the tiny embryo into the mother's womb," said Zernicka-Goetz. "This accessibility allows us to manipulate genes to understand their developmental roles in a model experimental system."
While the current research was carried out in mouse models, the researchers are developing an analogous model for human embryo development.
If these methods are shown to be successful with human stem cells in the future, they could also be used to guide development of synthetic organs for patients awaiting transplants.
"What makes our work so exciting is that the knowledge coming out of it could be used to grow correct synthetic human organs to save lives that are currently lost,” said Zernicka-Goetz. “It should also be possible to affect and heal adult organs by using the knowledge we have on how they are made."