John Gurdon Cell Quotations

The aim of a nuclear-transplant experiment is to insert the nucleus of a specialized cell into an unfertilized egg whose nucleus has been removed.

In principle. what is done is to take the nucleus out of a cell with a very fine micro-pipette or needle and introduce it into an egg. That had been done with amphibians a long time ago, and then there was a long pause of many years before people were clever enough to make that work in the sheep.

The importance of the egg's non-nuclear material - the cytoplasm - in early development is apparent in the consistent relation that is seen to exist between certain regions in the cytoplasm of a fertilized egg and certain kinds or directions of cell differentiation.

As with most animal eggs, the early events of amphibian development are largely independent of the environment, and the processes leading to cell differentiation must involve a redistribution and interaction of constituents already present in the fertilized egg.

As a brand new graduate student starting in October 1956, my supervisor Michail Fischberg, a lecturer in the Department of Zoology at Oxford, suggested that I should try to make somatic cell nuclear transplantation work in the South African frog Xenopus laevis.

Within one year of starting work, I had found that the nucleus of an endoderm cell from an advanced tadpole was able to yield some normal development up to the nuclear transplant tadpole stage.

It is particularly pleasing to see how purely basic research, originally aimed at testing the genetic identity of different cell types in the body, has turned out to have clear human health prospects.