Body-Building Nanog

These two dotty spheres are human embryos. The one on the left is normal. The one on the right has had a gene called NANOG inactivated via base editing – a precision tool that alters individual letters (basepairs) within the DNA code. The inactivation of NANOG has prevented the formation of any epiblast cells (cyan), which would ultimately develop into every cell of the body. The other embryonic cells (purple and yellow), which have remained intact, would contribute to supporting structures such as the placenta and yolk sac. Interestingly, this differs from mouse embryos, where Nanog deletion also affects the supporting structures, highlighting the importance of human embryo studies. This proof-of-principle work supports the use of base editing for studying gene function in human embryos – work that will not only provide valuable insights into early human development and pregnancy loss but potentially lead to improved IVF techniques.

Written by Ruth Williams

Ruth Williams

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Ruth is a freelance science journalist based in the US. She's a regular correspondent for The Scientist, and her work has appeared in The Lancet, Nature, Scientific American Mind, BBC Focus and elsewhere. Twitter @rooph

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• Image from work by Oliver J. Bower and colleagues, University of Cambridge Loke Centre for Trophoblast Research
• University of Cambridge Loke Centre for Trophoblast Research, Cambridge, UK
• Image originally published as 'with credit' equating to a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Research published in Nature, June 2026