The researchers developed the embryo model without eggs or sperm, from stem cells, the master cells that can become almost any type of cell.
Researchers of the University of Cambridge have created embryos from mouse stem cells that have a brain, a beating heart and the foundations of the other organs of the body, a model that supposes a new way to recreate the first stages of life.
The team, led by Professor Magdalena Zernicka-Goetzdeveloped the embryo model without eggs or sperm, from stem cells, the master cells that can become almost any type of cell.
The researchers mimicked natural processes in the laboratory by guiding the three types of stem cells that participate in the early development of mammals until the moment they begin to interact.
After 10 years, Cambridge scientists have finally succeeded in creating a model embryo with brain and beating heart, using mouse stem cells.
The advance will help us understand why some pregnancies fail and some succeed.@ZernickaGoetz @Cam_Repro @Caltechhttps://t.co/Og8lJADady
— Cambridge University (@Cambridge_Uni) August 25, 2022
By inducing the expression of a particular set of genes and creating a unique environment for their interactions, they got the stem cells to “talk” to each other.
The stem cells then self-organized into structures that progressed through successive stages of development. to create beating hearts, the bases of the brain, and the yolk sac, where the embryo develops and gets the nutrients in its first few weeks.
Unlike other laboratory embryos, these models managed to get the entire brain – including the anterior part – to start developing, which had never been achieved before.
Understand why some embryos fail
The team believe their results, published Thursday in the journal Nature, could help researchers understand why some embryos fail while others thrive in a healthy pregnancy.
Furthermore, the results could be used to guide the repair and development of human organs ‘synthetics’ for transplants.
“Our mouse embryo model not only develops a brain, but also a beating heart and all the components that make up the body. It’s amazing that we’ve come this far. This has been the soil of our community for years and the main objective of our work for a decade“, emphasizes Zernicka-Goetz, Professor of Mammalian Development and Stem Cell Biology.
For a human embryo to develop successfully there must be “dialogue” between the tissues that will form it and those that will connect it to the mother.
3 types of stem cells
In the first week after fertilization, three types of stem cells develop: one will eventually become the body’s tissues, and the other two support the development of the embryo.
One of these types of extra-embryonic stem cells will become the placenta, which connects the fetus to the mother and provides it with oxygen and nutrients, and the second is the yolk sac, where the embryo grows and gets its nutrients in the early stages of development .
Many pregnancies fail at the point that the three types of stem cells begin to send mechanical and chemical signals to each other, to tell the embryo how to develop properly.
For the last decade, Professor Zernicka-Goetz’s group at Cambridge has been studying these early stages of pregnancy, hoping to understand why some pregnancies fail and others 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 in the mother’s uterus,” explains Zernicka-Goetz.
To guide the development of their lab embryo, the researchers put together cultured stem cells from each of the three tissue types in the right proportions and environment to promote their growth and communication with each other.
They found that extra-embryonic cells send chemical signals to embryonic cells, but also mechanical, or through touch, guiding the development of the embryo.
A great advance of the study is the ability to generate the whole brainin particular the anterior part, which until now has been one of the main stumbling blocks in the development of synthetic embryos.
In the Zernicka-Goetz system, this works because this part of the brain requires signals from one of the extra-embryonic tissues in order to develop.
“This opens new possibilities to study the mechanisms of neurodevelopment in an experimental model”, argues Zernicka-Goetz.
human models
Although the current research was done in mouse models, researchers are developing similar human models with the potential to target the generation of specific organ types to understand the mechanisms underlying crucial processes that cannot be studied in real embryos.
Related news
Currently, UK law only allows you to study human embryos in the laboratory up to the 14th day of development.
If in the future the methods developed by this team work with human stem cells, they could also be used to guide the development of laboratory organs for patients awaiting transplants.