Dolly

(1996-2003)

The heaven sent sheep

Dr Martin Brookes

May 2003

Sheep rarely make headline news. They are instinctively modest creatures, herding animals content to form collectives of hill walkers and grass grazers. Dolly, however, was always destined to be different. Shunning the conventional ovine image she emerged from the flock to stand alone as the first sheep superstar. Dolly, of course, was no ordinary sheep. Her origins were unique. She was a copy, a genetic replica of a sheep that had already lived. In a bizarre twist of familial relations, her mother was also her elder, identical twin. Her birth seemed like a vindication of the impossible. Three scientists in Scotland had cleverly side-stepped the conventional rules of biology to create the first ever clone of an adult mammal.

Dolly was born on 5 July 1996 at the Roslin Institute in Edinburgh. She appeared normal and healthy and she bore no outward signs to betray her unorthodox beginning. Initially, her existence was kept secret until genetic tests could prove that she was, indeed, a clone. With her identity confirmed, Dolly went public on 23 February 1997. The announcement caused a sensation.

Before Dolly the received biological wisdom ran something like this. Life began when sperm met egg at conception. In the early stages of an embryo's development, all of its cells, the so-called stem cells, remain indistinguishable from one another. As yet, their fate is undecided. But as an embryo continues to grow, cells start to lose their autonomy as they take on concrete identities – to become muscle cells, skin cells or bone cells, for example. Once the fate of these cells is decided, there is no going back.

New era

That, at least, was the traditional view. But Dolly's birth was year zero for a new biological era. Clichés were dusted down and text-books hastily re-written. Dolly's creators had worked out a way of persuading an adult cell to regain its youthful independence. They had taken a single cell from an adult sheep (in this case, an udder cell from a six-year-old ewe) and, with some nifty biological jiggery-pokery, 'reprogrammed' it to become the first cell in the life of Dolly.

While the implications of this new technology were vast, most people had only one question on their minds. If it was possible to clone a sheep from an adult cell, then what about a human being? At the time, there was much wild and speculative talk about the resurrection of long-dead dictators, and the clonal continuation of living ones. Some confused souls saw cloning as a cure for mortality, seeming to forget that human clones, as naturally conceived identical twins, already existed.

There were opponents, of course, and lots of them. A mountain of ethical, moral and legal arguments was piled up to prosecute the spectre of human cloning. But many of the objections seemed to lack any real sense of legitimacy. The truth was that Dolly had caught us all off guard. The fall-out that followed her birth was the inevitable consequence of a society that was ill-prepared for her discovery.

Immune to all the fuss, Dolly continued to thrive. Further confirmation that she seemed to be in full working order came when she gave birth to six healthy offspring of her own. This time the lambs were conceived in conventional style, using the tried and trusted technique of a good old-fashioned male. Dolly was the perfect mother, gentle, doting and affectionate.

Short life

But in January 2002 a dark cloud appeared on the horizon when vets discovered that Dolly was suffering from arthritis in the hip and knee of her left hind leg. While arthritis is not unknown in five-year-old sheep, the revelation caused alarm. It hinted that Dolly might be suffering from premature ageing, a much mooted side effect of cloning from adult cells. Suspicions seemed to be confirmed when, a year later, she was diagnosed with a progressive lung disease that effectively ended her life. She was put to sleep on 14 February 2003.

At six years of age Dolly died relatively young. Sheep can live for up to 14 years. But, in truth, it's impossible to say whether her death had anything to do with her being a clone. A post-mortem revealed that she had been suffering from a virus-induced lung tumour, but the condition is not uncommon in sheep of her age. A single isolated death provides insufficient information from which to draw definitive answers. Dolly was a clone, but she was also a superstar who led an overfed life indoors. Many more Dollys will be needed before the long-term health risks of cloning can be subjected to statistical scrutiny.

Dolly's legacy

With Dolly now dead, how can we assess the legacy of this extraordinary sheep? She was, undoubtedly, a pioneer, a template for a new breed of identikit animals. Since her creation, cloning has become relatively commonplace and today, we have clones of mice, cattle, goats, pigs and cats. But while many are fascinated by the reproductive implications of cloning and a future era of human clones, the real value of Dolly's legacy must surely lie elsewhere.

What made Dolly possible was the ability to reset biological switches and bless adult cells with an entirely new potential. With that remarkable discovery a door was opened on a whole new world of medical possibilities. Most of the tissues in our bodies lack any kind of regenerative capacity. That is why neurodegenerative diseases like Alzheimer's and Parkinson's are so damaging. Once nerves are diseased or damaged they cannot re-grow. But Dolly and the cloning technology that she has spawned now suggest a miraculous solution. If adult cells can be re-trained for new roles then cloning technology could be used as a tissue replacement therapy tailor made to an individual patient's needs.

Dolly's own tissues are now on permanent display in the National Museum of Scotland. But a visit isn't necessary to appreciate her gift to the world. The sheep is gone, but her influence is already cemented into the fabric of our future.

You may also be interested in these other Channel 4 articles

The Race to Make a Human
The story behind the mavericks striving to be first past the post in the human cloning game.

Cloning Ourselves – How Close Are We?
The truth behind recent cloning claims, the reasons for doing it and the dangers involved.

Cloning Ourselves – Ethical Dilemmas
The potential to make a living clone is already with us, here are the ethical arguments laid bare.

Cloning a Cure – How Close Are We?
How cloned human embryos could heal the sick, including the methods and the motivation.

Cloning a Cure – Ethical Dilemmas
A way of healing the sick that involves destroying tiny human embryos. Is it worth the cost?

Immortality – Hype or Hope?
How cloned stem cells will leave no branch of medicine untouched. How long would you like to live for?

Cloning FAQs
Answers to some commonly posed questions. Including the difference between the two types of cloning and what stem cell therapy could do for us.

Severino Antinori biography
The independent fertility specialist who wants to clone whole human beings.

Francis Galton biography
Introduction to the life and work of the man known as the 'Father of Eugenics'.

Find out more

Channel 4 is not responsible for the content of third party sites

Websites

Roslin Institute, Edinburgh
www.roslin.ac.uk
Scientists here created the first ever clone of an adult mammal in 1997, Dolly the sheep. Almost all the research is published in the public domain. The 'public interest' pages offer summaries of published reports on mammalian cloning, the technology, its progress, ethics, plus discussion papers, press articles and an image library.

Clonaid
www.clonaid.com
This private US organisation has pledged to be the first to clone an adult human and offers a range of services, including Clonapet, promising the possibility of cloning a deceased family pet. Note that the organisation was set up by Rael, spiritual leader of the Raelian religious cult movement and the world's largest UFO-related organisation.

Advanced Cell Technology
www.advancedcell.com
Website of the company claiming to have cloned the first human embryo.

New Scientist
www.newscientist.com/hottopics/cloning
Up-to-date articles and information on the ongoing cloning debate.

Pondering the Ethics and Science of Stem Cells
www.upenn.edu/gazette/0302/0302gaz1.html
Article on the ethical issues raised by stem cell research.

Bioethics.net
http://bioethics.net
Amercian Journal of Bioethics website. News and features on may subjects, including cloning, to suit all levels of knowledge.

Primer on ethics and human cloning
www.actionbioscience.org/biotech/mcgee.html
Article, on the Action Bioscience website, introducing the key issues in human cloning and ethics.

Genetics
www.channel4.com/genetics
Channel 4 site accompanying Sir John Sulston's Royal Institution Christmas Lectures. Includes the first 'artificial life experiment' designed for the general public.

Books

	A Clone of your Own? by Arlene Judith Klotzko (Oxford University Press, 2002) The writer-in-residence at the Science Museum takes a look at the science and ethics of cloning. Get this book
	The Cloning Sourcebook by Arlene Judith Klotzko (Oxford University Press, 2001) Aimed at increasing public understanding of cloning. Discusses animal cloning since the birth of Dolly the Sheep and the questions raised by cloning for society. Get this book
	The Impact of the Gene: From Mendel's peas to designer babies by Colin Tudge (Hill & Wang, 2001) In the mid-19th century a friar, Mendel, discovered the basic laws of heredity. Tudge examines the influence of Mendel's ideas, considering the evolution of genetics as a science, and addressing questions of ethics, the public's fears about cloning and eugenics. Get this book
	The Second Creation: The age of scientific control by the scientists who cloned Dolly by Ian Wilmut, Keith Campbell and Colin Tudge (Headline, 2001) Recounts not just how Dolly was created, but also the techniques for her predecessors who were cloned from embryo cells. It explains the scientific reasons behind the research, and discusses where this technology will lead and the ethical issues that have been raised. Get this book
The Secrets of Life: Genes and genetics from evolution to engineering (Channel 4, 2001) £4.95 (inc P&P) Cheque or postal order payable to Channel 4 Television, send to: The Secrets of Life, PO Box 400, Wetherby, LS23 7LG or phone + 44 (0) 8701 246 444 Colour booklet, published to accompany the Channel 4 screening of the Royal Institution Christmas Lectures. Follows Sir John Sulston's journey from the beginnings of life to the latest developments in biotechnology and into the future. Discusses ethics of cloning.

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