Reengineering Life
Scientists Can Now Grow ‘Synthetic’ Early Human Embryos in a Dish
The research reignites a debate over embryo research
Reengineering Life is a column from Future Human about the ways humans are using biology to reprogram our bodies and the world around us.
Under a microscope, the little balls of cells look like five-day-old human embryos, known as blastocysts. They’re similar in size, shape, and structure. They even have the three distinct cell types that exist in real blastocysts — the kind that forms the embryo itself, another that makes the placenta, and a third type that gives rise to the sac in which the embryo will develop.
But there’s one key difference between these embryo look-alikes and natural ones: They weren’t made with human eggs and sperm.
In two papers published March 17 in the journal Nature, researchers report that they created living structures that resemble early embryos using human skin cells and stem cells. Scientists have previously made “synthetic” mouse embryos and even used them to grow a mouse fetus. And last year, scientists described making versions of later-stage human embryos. These, however, mimic an embryo at an even earlier stage and are among the most complete models of a human embryo to date.
