Under his microscope, Jun Wu could see several tiny spheres, each less than 1 millimetre wide. They looked just like human embryos: a dark cluster of cells surrounded by a cavity, and then another ...

The earliest days after fertilization, once a sperm cell meets an egg, are shrouded in scientific mystery. The process of how a humble single cell becomes an organism fascinates scientists across ...

Researchers at the Francis Crick Institute have developed a new stem cell model of the mature human amniotic sac, which replicates development of the tissues supporting the embryo from two to four ...