A Christ's alumnus has been awarded the Nobel Prize for Medicine.

Sir Martin Evans, who has been credited with the discovery of embryonic stem cells and the production of the first "knockout mouse", was yesterday announced the joint winner of this year's prize with Professors Mario Capecchi of the University of Utah and Oliver Smithies of the University of North Carolina.

The three scientists' work on knockout mice and gene targeting has had a significant influence on our understanding of disease.

 The "knockout mouse" is a genetically engineered mouse that has had one or more of its genes made inoperable. By inactivating the gene and studying any differences that follow, scientists can infer the likely function of the gene. The method has already generated over five hundred mouse models of human disorders, including arthritis, diabetes and Parkinson's disease.

Sir Martin Rees, professor of cosmology and astrophysics and Master of Trinity College, described the announcement as "a fitting recognition of Sir Martin's groundbreaking research on embryonic stem cells.

"He is a world leader in mammalian genetics and his research has undoubtedly increased our understanding of human diseases. Stem cell research has immense potential. It is a field in which UK scientists such as Martin have made pioneering contributions and maintain a powerful presence."

Professor Jim Smith, Chairman of the Gurdon Institute where Sir Martin Evans worked in the 1990s, said, "Martin Evans's work paved the way for the creation of ‘knock-out' mice. His work has been, and will be, hugely important for our understanding of development and disease, and this award is richly deserved."

Dr Bill Colledge, who worked in Sir Martin Evans' lab from 1988 to 1995, said, "this award is an acknowledgment of the outstanding contribution that Martin Evans played in developing the technology that allows us to study the function of genes in a whole animal."

Evans graduated from Christ's in 1963 and completed a PhD at UCL. He returned to Cambridge in 1978 and was appointed Professor of Mammalian Genetics at the Department of Genetics.

It was at this point that he began to develop genetically mutated mice, and discovered the potential of embryonic stem cells for tissue regeneration after injury or disease.

He became an Honorary Fellow of St Edmund's College in 2002. He is currently Professor of Molecular Genetics at Cardiff University.

Bradley Norman