Lessons from the Dolly the Sheep Experiment

On 19th October 2010 I went to a talk at the Royal Society by Professor Sir Ian Wilmut who supervised the team that cloned Dolly the sheep back in 1996.

Sir Ian is Director of the MRC Centre for Regenerative Medicine in Edinburgh and has a PhD from Cambridge on embryo deep freeze methods. The centre’s mission is to understand how stem cells can repair tissues and be used in degenerative diseases.

In his talk, Sir Ian explained how stem cell research could help in the future to reprogramme cells and replace those that are damaged or have died. In this sense, there is a potential opportunity to use stem cells as a therapeutic tool for degenerative diseases like Parkinson’s, motor neuron diseases (paralysis) and psychiatric disorders.

We are still in the early phases of developments and this subject is loaded with moral dilemmas, including finding embryo donors, as well as the risks involved in implating so called Induced Pluripotent Cells (modified cells that have the ability to form new tissues) into a patient’s body as they may transmutate into tumors.

Professor Wilmut believed the process still needs improving and it will be years before we will see any therapeutic application of the research. His main concern was accuracy as currently you cannot control how cells change and perform over time.

Since the first experiments on sea urchins in 1892, stem cell research has been used for purposes like skin repair and bone marrow transplants. Embryo cells have a longer shelf life than stem cells which grow for a short time in vitro, however their behaviour is less predictable.

Looking back at the Dolly the sheep experiment, the process involved taking a donor cell from the mammary gland in an ewe in the third trimester of the pregnancy. The surrogate mother’s main physical characteristic was having a black face, whereas Dolly was born with a white face (the dominant gene from the donor).

Dolly eventually died at age 6 after contracting lung cancer which had affected other sheep at the same time.

There are no ultimate solutions or answers as yet because research into cell re-programming is still in its infancy. The potential of this research to treat degenerative diseases could be significant but it is too early to say as more trials are needed.

By Paola Bassanese