In frog spawn in a pond, each egg is able to turn itself into a tadpole and eventually a frog, with no help or guidance from a parent frog or from anything else in the pond. The single egg will have no resemblance in any respect to what it will turn into. We now begin to understand how this extraordinary transformation takes place. Eggs of frogs and other animals have another remarkable property. If a single cell from adult skin is transplanted into an egg, the skin cell will be made to go backwards in development to become an embryo cell from which another adult can be formed (repeating the process of normal development). In this way it is now possible to replace aged or diseased cells of an adult with rejuvenated cells from their skin. This is opening the possibility of cell replacement in humans.

Biography
John Gurdon was judged at school to be wholly unsuited to science having come bottom in a class of 250 in Biology. However, he was able to take up science at Oxford University, where he also did a PhD. His work led to the concept that an egg has the ability to rejuvenate the nucleus of an adult cell, and hence to the current prospect of replacing aged and diseased cells in humans with new cells derived from other body cells such as skin. In mid career he moved to Cambridge where he still works in the University. He is an Honorary Fellow of Christ Church, Oxford, and of Magdalene and Churchill Colleges in Cambridge. He served as Master of Magdalene from 1995-2002. He has received a number of awards including the Copley Medal of the Royal Society (2003), the Lasker Award for Basic Medical Research (2009), and the Nobel Prize for Physiology or Medicine (2012). 

Reprogramming Animal Development - Professor Sir John Gurdon

University of Cambridge