Inducible Stem-Cell-Derived Embryos Capture Mouse Morphogenetic Events In Vitro.

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Embryogenesis

Background:

• Embryo-like structures (ETX embryos) using embryonic stem cells (ESCs), trophoblast stem cells (TS), and extra-embryonic endoderm (XEN) stem cells partially model mouse gastrulation.
• ETX embryos exhibit limited recapitulation of complex morphogenic events like gastrulation, potentially due to XEN cell limitations.

Purpose of the Study:

• To enhance in vitro embryo models by improving their developmental potential.
• To investigate the role of transient Gata4 expression in ESCs for generating more robust embryo-like structures.

Main Methods:

• Generated ESCs engineered to transiently express the transcription factor Gata4.
• Combined these modified ESCs with standard ESCs and TS cells to create induced ETX (iETX) embryos.
• Analyzed iETX embryos for key developmental events including symmetry breaking and gastrulation.

Main Results:

• iETX embryos successfully established a robust anterior signaling center that broke embryo symmetry.
• These iETX embryos underwent gastrulation, forming embryonic and extra-embryonic mesoderm and definitive endoderm.
• Replacing XEN cells with Gata4-expressing ESCs significantly increased the developmental potential of the in vitro embryo models.

Conclusions:

• Transient Gata4 expression in ESCs enhances the developmental capacity of in vitro embryo models.
• iETX embryos provide a more accurate system for studying early mouse embryogenesis, including anterior-posterior patterning and gastrulation.
• This improved model system facilitates in vitro research into fundamental developmental processes.