Mouse Epiblast Stem Cell - Stem cell that's almost human

Scientists in the UK and America have discovered a new type of mouse stem cell that's effectively identical to human embryonic stem cells. This means that researchers can use these mouse cells to discover how to unleash the power of human stem cells, but without having to work on human embryos. Roger Pedersen from Cambridge Universityand Ron McKay from the NIH in Maryland each made the discovery independently. They took cells from a layer in the embryo called the epiblast, which normally goes on to form the future body. When these cells were grown in the dish they behaved identically to human ES cells; they required the same culture conditions to keep them alive and they could turn into all of the cells of the future body. Prior to this finding scientists had been puzzled for a long time because the cells they collected from mouse embryos and were calling "mouse ES" cells behaved in a totally different manner to their human equivalent and no one could understand why. It also meant that, despite our thorough knowledge of mouse genetics and development, mice couldn't be used as a model for the function of human stem cells, because the cells were so different. Now it's clear that scientists were studying the wrong thing. "What makes these cells so exciting is they provide a model for understanding human embryonic stem cells that adds the awesome power of mouse genetics, and the physiology of rats", Pedersen points out.