Researchers from the Francis Crick Institute have now developed an exciting new 3D model, referred to as the post-gastrulation amnioid (PGA). This model very accurately recapitulates the human amnion and its supportive tissues. This novel model represents a groundbreaking step towards understanding early human development. Specifically, it seeks to address the major gap that exists after gastrulation.
The PGA was created by specifically culturing human embryonic stem cells. It took researchers two chemical signals and step-by-step instructions to a molecular assembly line over the course of 48 hours to do so. Remarkably, the cells within the PGA self-organized into distinct inner and outer layers, replicating the structure of the amnion. By day 10, over 90% of the PGAs formed a vascularized sac-like structure. This outcome exemplifies the model’s high reproducibility and structural fidelity.
During this 90-day period, the PGAs expanded by historic proportions. Their success without requiring any further signals was a testament to their capability to prosper independently. The PGAs featured two apparent cell populations, extra-embryonic mesoderm and amniotic endoderm. They just kept growing, getting large enough to observe with the naked eye through their culture flasks. Though these two-membrane sacs took on the same growth trajectory, most of them yielded such different sizes.
Beyond its use in predicting drug development outcomes, the PGA model provides new knowledge into the early development of humans. It accomplishes this without the ethical controversies associated with use of human embryos. Realizing that the connective structure and function of the PGA could closely resemble the human amniotic sac, Dr. This remarkable research innovation offers scientists a new, essential resource for studying this key stage of development.
This creative new model represents the first time scientists were able to witness amniotic sac development past the two week mark. This is discovery close a critical hole in our understanding of. We’ve fully described our findings in a recent study, which you can read through DOI 10.1016/j.cell.2025.04.025. Policy impact This research highlights its importance for future policy-focused investigations in the field.