The Science Hour

Scientists know very little about the first few days of the life of a human embryo, once it's been implanted in the womb. Yet this is when the majority of pregnancies fail. Professor Magdalena Zernika-Goetz at Cambridge University is a leader in the field of making 'model embryos' in both mice and humans. Model embryos until now have been grown in the lab from donated fertilised eggs, but these are hard to come by and governed by strict laws and ethical guidelines. Now researchers in the University of Michigan have used human pluripotent stem cell lines (originally isolated from embryos, but kept and nurtured as clumps of dividing cells in petri-dishes for many years) to make a model embryo that has shown signs of development and organisation in the crucial 7-10 day window. We discuss how helpful these will be to understanding crucial early stage pregnancies and as a tool to test drugs, treatments and disease processes. The ethical side of growing human embryos from stem cells is addressed by Stanford Univers