TV Review: Dolly – The world's most famous sheep

Dolly the sheep was born on 5 July 1996 in Scotland. A recently released Channel 4 documentary covers the cloning of Dolly and explains its scientific and historical significance – from somatic cell nuclear transfer to Fidel Castro's excitement over her creation.

Discussions about Dolly tend to pitch camp on one of two sides: the scientific, getting into the weeds of cloning; or the ethical, dwelling on the wider questions her existence raised. 'Dolly: The World's Most Famous Sheep' discusses both in a superficial yet entertaining way.

For anyone meeting Dolly for the first time, the basic story is this: agricultural scientists at the Roslin Institute near Edinburgh took the nucleus from cells first sourced from an adult sheep's mammary gland and transferred it into egg cells stripped of their own nuclei. The resulting embryos were then transferred into surrogate sheep, with only one out of hundreds successfully coming to term.

Dolly was the first mammal born using this technology with an adult cell rather than an embryonic one, and that distinction is the whole story. What Dolly demonstrated is that a specialised, 'differentiated' cell – in this case, from a sheep's mammary gland – had not lost the genetic instructions needed to start development again. This challenged the prevailing idea that cell development was a 'one-way process' in which pluripotency was lost.

The impact on biology cannot be understated. 'We can see the birth of Dolly as the Big Bang that exploded an entire field of research,' says Dr Kat Arney, a science writer interviewed throughout the documentary. 'You basically unlock biological time', she adds, pointing to the importance of this concept to ignite the field of regenerative medicine and inspiring techniques such as iPS (induced pluripotent stem) cell reprogramming.

However, the documentary avoids excessive scientific discussion and quickly moves to how the public imagination was captured by the ethical concerns: 'Well, are humans next?' recalls Dr Alan Colman as 'the main focus of attention'. Dr Colman was research director at PPL therapeutics in Edinburgh, the biotechnology company that held the commercial license to the technology used to create Dolly.

The sentiment was certainly fuelled by some of the media portrayal at the time: a TIME magazine's 1997 cover showed Dolly under the thrilling headline 'Will There Ever Be Another You?', not far from Nature's 'A flock of clones' cover when Dolly's discovery was published.

The imagined implications overtook the real impact before anyone had time to sit with it. 'I lectured in Cuba and Fidel Castro got in touch with me. He was interested in whether our company could clone a cow that had been a wonderful milker,' cheerfully remembers Dr Colman, as an example of how far-reaching Dolly's fame was.

Indeed, documentaries about her cannot seem to resist the word 'world' – BBC Scotland aired 'Dolly: The Sheep That Changed the World' in 2021. The two productions open almost identically, tracing how scientists working in a little-known research institute ended up cloning an adult mammal and stumbling into worldwide headlines. I point readers interested in the backdrop story toward BioNews' review of that earlier film (see BioNews 1131).

Where this new documentary distinguishes itself is in tone: it is breezier, more interested in Dolly as celebrity than Dolly as protocol. But I am not convinced the change in focus buys much of a change in film. Both documentaries lean on the same well-worn footage – US president Bill Clinton banning cloning in humans, the Pope raising concerns on how 'it reduced humans to mere objects'... I found it hard to assess one documentary without measuring it against the other. The lab explanations are broadly similar too, though the BBC version still has the edge for anyone who wants to understand more of the scientific detail.

I think the cultural phenomenon was a good angle to take. What I wanted more of was the cultural moment itself: the public's relationship with genetic engineering in 1997, held up against ours today. The documentary gestures at this backdrop, with Dr Arney's mentioning Jurassic Park, genetically modified food scares and the infamous 'ear-mouse' – but the documentary does not go much further. Conversations with bioethicists and historians could have added depth to this angle.

I would recommend this documentary to anyone coming to Dolly's story fresh and looking for an entertaining primer on the science, paired with a sense of just how strange her reception was. If nothing else, the story is a useful reminder that communicating science is not only about explaining what is technically possible. It is also about anticipating what people may imagine once announced.