John Gurdon, British Developmental Biologist

Sir John Gurdon, the British developmental biologist and famous scientist, keeps a framed note from his former biology teacher over his desk. It reads – “I believe Gurdon has ideas about becoming a scientist. On present showing, this is quite ridiculous. If he can’t learn simple biological facts he would have no chance of doing the work of a specialist, and it would be a sheer waste of time both on his part and of those who would have to teach him.”

Gurdon was fifteen at the time of this pronouncement, had done exactly one semester of science at Eton and was discouraged from doing any more. No one, certainly not the biology master, had any idea that he would go on to have a distinguished career in developmental biology and do pioneering work in nuclear transplantation and cloning research.

In the immediate aftermath of the Second World War, science was rather a grim business of rote-learning facts and note-taking, things Gurdon didn’t excel at. After his biology master’s disenchanted verdict, he switched to the Classics, studying Latin and Greek for the remainder of his time at Eton. He considered becoming a Classicist; his worldlier father suggested a career either in the army or the financial sector. As it turned out, the job in the financial world didn’t fructify, the army refused him and his application to study the Classics at Christ Church, Oxford, met with a rather strange response.

The admissions tutor at Oxford, Hugh Trevor-Roper, sent him a letter saying that they would accept him if he came immediately and if he agreed to study Science rather than the Classics. Such a scenario would be improbable today, but back then Oxford was actually short of science students and, according to Gurdon, Trevor-Roper, busy with the wartime politics, was eager to fill up the seats with anyone he could find.

So Gurdon entered the Zoology Department at Christ Church, Oxford, under Sir Alister Hardy, and his parents paid for a year’s extra tuition in science for him to catch up with all he had missed in school.

Later, his fascination with insects led him to apply for a Ph.D. with the Entomology Department. Not accepted, he took up embryology under Michael Fischberg.

On Fischberg’s suggestion, Gurdon did his Ph.D. dissertation on nuclear transplantation in Xenopus laevis (South African clawed frogs). He began by repeating the nuclear transplantation experiments of Briggs and King. They were the first to successfully transplant the nucleus from an early stage cell into an egg, but their experiments to similarly transplant the nucleus from later stage cells had failed. This led them to mistakenly conclude that –

With development, genetic material underwent irreversible change and was no longer capable of going back to the roots so to speak.

This is of course not the case. All our cells have the same set of genes. Moreover Gurdon’s experiments proved that genetic material does not undergo irreversible change with development. He removed the nucleus from a differentiated intestinal cell of a tadpole and transplanted it into an enucleated frog egg. This egg then grew and produced a tadpole clone genetically identical to the tadpole that had donated the intestinal cell nucleus.

Two things then worked in Gurdon’s favor – first was the availability of an ultraviolet microscope to enucleate a cell. Then there was the discovery by another of Fischberg's students; it was the finding of a mutation that acted as genetic marker. Gurdon took the nucleus of a genetically marked cell and put it in an egg. The developed embryo contained the genetic marker, thereby proving successful transplantation. Without this evidence, the scientific community wouldn’t have believed Gurdon. As it was, the experiment attracted much controversy. He was a mere graduate student; Briggs and King were well-established researchers.

After Gurdon received his Ph.D, Fischberg advised him to do “something completely different” and Gurdon proceeded to Cal-Tech to do post-doctoral work in bacteriophage genetics. His experiments here, according to him, were not successful, but the experience was invaluable.

After returning to the UK, John Gurdon took up the post vacated by his mentor Michael Fischberg (who had taken up a post in Geneva) at the Department of Zoology of the University of Oxford. He worked here as a Professor from 1962 to 1971.

His later career was mainly centered at Cambridge –

Research Professor and later Head of Cell Biology Division at the MRC Laboratory of Molecular Biology (1971-1983)

Research Professor - the John Humphrey Plummer Professorship of Cell Biology - at the Department of Zoology, University of Cambridge (1983-2000)

Founding member with Professor Ron Laskey of the Cancer Research Campaign Unit of Molecular Embryology in the Zoology Department of Cambridge University, and later Chairman of the Wellcome CRC Institute of Cancer and Developmental Biology (1989-2001)

Master of Magdalene College, Cambridge (1995-2002)

Over the years, he has been chiefly concerned with research in nuclear transplantation and the molecular mechanism of how a transplanted nucleus is reprogrammed. Gurdon identified the elements that told a cell how and in which direction to proceed. First there’s prefertilization controlled development whereby the egg already has existing information about how it should develop, secondly asymmetric cell division where the cells select their pathway, thirdly signaling between cells to know in which direction to develop, and then fourthly community effect which is also about the development direction of cells.

Gurdon’s research has also looked into gene expression and using Xenopus eggs and oocytes for messenger RNA molecule microinjection, and into the analysis and use of signaling factors in cell development, differentiation and redirection.

He has received many awards and recognitions, including the Scientific Medal of the Zoological Society (1968), Fellow of the Royal Society (1971), Emperor Hirohito International Prize for Biology from Japan (1987), and the Conklin Medal from the Society for Developmental Biology (2001).

http://www.bioch.ox.ac.uk/glycob/rodney_porter_lectures/1999/gurdon.html

http://globetrotter.berkeley.edu/people6/Gurdon/gurdon-con1.html