One of the most defining moments of life is the crucial step in embryonic development when a vague ball of cells reorders into the orderly three-layered structure that sets the stage for everything to come. This critical process, also known as gastrulation, occurs in the third week of human development.
Gastrulation is the origin of our own individualization, the emergence of our axis. It is the first moment that separates our head from the butt.“
– Ali Brivanlou, Rockefeller University
Studying the molecular basis of this crucial event would greatly assist scientists in preventing miscarriages and developmental disorders. The investigation of human gastrulation, however, has proved both technologically challenging and ethically complex, limiting the current approaches to expanding our understanding of early human development. Now, Brivanlou and colleagues have demonstrated how a stem cell model system known as Blastoids can allow the examination of the nuances of human gastrulation in the presence of extraembryonic cell types before implantation. Their study, published in Stem Cell Reports, describes the scientific and clinical potential of this new platform.