Researchers at the University of Cambridge have recently succeeded in creating the world’s first mouse embryo-like structure using embryonic stem cells (ESCs) and trophoblast stem cells (TSCs). Led by Professor Magdalena Zernicka-Goetz, the research team combined genetically modified mouse ESCs and TSCs in a three-dimensional extracellular matrix to create a self-assembling structure with properties similar to a natural embryo.
Mammalian embryogenesis requires intricate interactions between embryonic and extra-embryonic tissues to orchestra morphogenesis with changes in developmental potential. By using genetically modified stem cells and specific inhibitors, the team showed that embryogenesis of ESC- and TSC- derived embryos, ETS-embryos, depends on the crosstalk involving Nodal signaling.
According to Zernicka-Goetz, embryonic and extra-embryonic cells communicate with one another to form a structure that resembles an embryo, sharing anatomically identical regions with similar rates of development. A striking revelation elucidated by the study is that communication between cells is bidirectional in nature, in which cells guide each other in the biological development of the organ. previous attempts to grow embryo-like structures using only ESCs have been met with limited success precisely because different cell types lack this critical coordination.
In Zernicka-Goetz’s model, cultured stem cells organized themselves, with ESCs and TSCs on opposing ends. A cavity then opened up within each cluster before joining together, eventually becoming the large, pro-amniotic cavity in which the embryo developed.
The creation of this artificial embryo-like structure is critical in facilitating insights into the developmental process of a natural human embryo. Similar approaches could one day be used to explore fetal growth shedding light on the role of the maternal environment in birth defects and health.
Written by Sabrina Lin
References may be found in the journal.