Two US scientists and their UK collaborator have been awarded the Nobel Prize for medicine for their groundbreaking work in gene technology.

Mario Capecchi, Oliver Smithies and Briton Martin Evans developed a technique known as gene targeting.

It enabled them to replicate human diseases in mice by introducing genetic changes into the animal's stem cells.

The Nobel Committee said this had led to many new insights into conditions such as cancer and heart disease.

For instance, science has gained a greater understanding of how disease can strike otherwise healthy people.

The technique has also helped to shed new light on the ageing process, and on how the embryo develops in the womb. It can be used to study almost every aspect of mammalian physiology.

In its citation, the Nobel Committee praised the technique as 'an immensely powerful technology' which was now being used in virtually all areas of biomedical research.

'Gene targeting in mice has pervaded all fields of biomedicine,' it said.

'Its impact on the understanding of gene function and its benefits to mankind will continue to increase over many years to come.'

The technique is commonly described as gene 'knockout'.

It enables scientists to silence specific genes, and monitor the effect, so that gene-by-gene they are able to build a picture of the development of disease.