Early human development is orchestrated by finely tuned genetic ‘switches’ that transform the fertilized egg into a complex, multicellular organism. Although such developmental processes are evolutionarily conserved across many species, species-specific changes have been key drivers of developmental innovations throughout evolution. Uncovering human-specific molecular mechanisms that underlie embryo development is important for making advances in reproductive and regenerative medicine. However, this research is technically and ethically challenging because it typically relies on surplus embryos from in vitro fertilization. Writing in Nature, Fueyo et al.1 report their use of stem-cell-based models to reveal that a type of ancient DNA sequence, inserted previously into the human genome, acts as an essential switch for early embryonic development.
Competing Interests
V.P. is one of the inventors on a patent application (PCT/EP2023/073949) filed by KU Leuven, Belgium, describing the protocols for inducing extra-embryonic mesoderm cells using naive human pluripotent stem cells.
