Researchers have identified the gene NANOG as the key switch that initiates the developmental program resulting in cells forming a human body. The finding came from precise DNA edits to fertilized human eggs using CRISPR base editing.
Kathy Niakan at the University of Cambridge led the work, which revealed that NANOG plays a different role in people than in mice. When the gene was disabled in donated human eggs, none of the cells developed into those that form the embryo itself.
The embryos still looked normal under a microscope. Niakan noted that this could explain why many IVF embryos fail to implant even when they appear viable.
The study, published in Nature, also showed that base editing reduces some risks compared with earlier CRISPR methods. Niakan stressed that the technology remains far from use in creating gene-edited children.