CGS-authored

Illustration of an 8-cell stage embryo

A genetic tool allows researchers to disable a gene key to human development in a closely regulated experiment

For the first time, scientists edited a gene in fertilized human eggs critical to early development. The experiments helped the researchers learn about fundamental human biology in a way they could not through research on mice.

Researchers led by Kathy Niakan, a developmental biologist at the Francis Crick Institute in London, disabled a gene that codes for a protein called OCT4, known to be active in stem cells that can develop into all the cell types found in the body, reports Gretchen Vogel for Science. Turning the gene off ensured that cells from fertilized human eggs failed to form placental cells, yolk sac cells or even cells that would typically become a fetus.

Disabling the same gene in mouse embryos gives different results: Those embryos became balls of mostly placental cells. The findings suggest that the gene controls the fate of several cell lineages and plays a slightly different role in humans than in mice.

"This is opening up the possibility...