How is stem cell cloning different from human cloning?
The use of stem cells for therapy is very well established in the mouse field. Scientists have been working on embryonic stem cells in the mouse for almost twenty years. It’s important to remember that whilst a stem cell in the mouse will turn into a fully blown mouse, it does this in a very developmentally programmed way. We don’t understand how it does it but it turns into a mouse. That’s a property of two things. First of all the cell itself knows what it has the potential to become but it also has to react to other things around it. So a liver, for example, doesn’t develop as a liver separately, it develops as a liver in the context of all the other organs and all the other body tissues. So in a culture of these cells, what scientists have had to work out is how you reproduce those signals. How would you take cells and push them into becoming a liver cell, or push them into becoming an insulin-secreting cell? People have worked out ways of doing this in the mouse. So, for example,
