NANOG Gene's Role in Early Human Embryo Development Confirmed
A study led by developmental biologist Kathy Niakan from the University of Cambridge has confirmed that the NANOG gene plays an essential role in early human embryo development, but its function differs from that observed in mice.
The research, published in Nature, used base editing—a technique that changes a single base in DNA—to disrupt NANOG in normal human embryos (not tripronuclear) and human embryonic stem cells, without causing off-target effects.
Key Findings
- With NANOG disabled, pluripotent epiblast cells could not transform into stem cells and were redirected to form yolk sac or placental cells.
- The embryos prioritized support structures over fetal development.
- Unlike in mice, NANOG was not essential for yolk sac development in humans.
Methodology
Base editing was used instead of CRISPR/Cas9 knockout to avoid unwanted DNA changes. Embryos were donated from assisted conception or generated from donor gametes; they were not allowed to develop beyond 14 days.
Implications
Stem cell scientist Dusko Ilic of King's College London noted that the study's immediate value is mechanistic, not clinical, and does not demonstrate safe embryo editing for clinical use.
Developmental biologist Robin Lovell-Badge of the Francis Crick Institute stated that understanding early embryo development could help reduce distress related to infertility and pregnancy loss.