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Base Editing Halts Human Embryo Epiblast, Study Finds

6/26/2026

Summary

Niakan Blocks Epiblast

Professor Kathy Niakan led a UK team that used base editing—a CRISPR tool that edits nucleotides with reduced off-target errors—to inactivate NANOG in embryos, blocking epiblast formation.
In human embryos, NANOG loss blocked epiblast while placenta and yolk-sac tissues formed.
In mouse embryos, Nanog inactivation disrupted epiblast and trophoblast, showing a species contrast.
The results were published in Nature on 2026-06-25 by Monash, Broad Institute, Francis Crick Institute and clinics.

Summary

Researchers Edit Embryos

Researchers reported that base-editing produced human embryos that reached a stage viable for uterine transfer but were mosaic, containing both edited and unedited cells.
The finding revived ethical debate over whether germline base editing constitutes therapeutic correction or trait enhancement.
The article noted public curiosity about funding sources for high-risk genome-editing projects.
Lead investigators provided contact details via encrypted Signal accounts, reflecting privacy concerns amid potential backlash.

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Niakan Blocks Epiblast

Professor Kathy Niakan led a UK team that used base editing—a CRISPR tool that edits nucleotides with reduced off-target errors—to inactivate NANOG in embryos, blocking epiblast formation.
In human embryos, NANOG loss blocked epiblast while placenta and yolk-sac tissues formed.
In mouse embryos, Nanog inactivation disrupted epiblast and trophoblast, showing a species contrast.
The results were published in Nature on 2026-06-25 by Monash, Broad Institute, Francis Crick Institute and clinics.

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