Celebrating Dolly the Sheep’s legacy, 25 years on

Published: 5 July 2021

Dolly continues to inspire scientific developments worldwide, 25 years after she was born at the Roslin Institute.

Scientists reflect on the impact of Dolly the Sheep, some 25 years after she became the first mammal to be cloned from an adult cell.


Dolly’s story made news headlines around the world, and she continues to be regarded as a scientific milestone.

The pioneering research that led to Dolly’s creation paved the way for ongoing discoveries using stem cells and gene editing.

Dolly was created by replacing the nucleus in an egg cell from a Scottish Blackface sheep with the nucleus of an adult udder cell from a white-faced Finn Dorset sheep. She was born to a surrogate Blackface ewe. It was the first time that an adult cell had been used to create a cloned animal.

The research that led to Dolly has supported new understandings of stem cells – early stage cells that can develop to form various tissues. Scientists are researching how to control their development, and how mature cells may revert to behave once more as undeveloped cells.

Insights from Dolly have also enabled advances in gene modification and gene editing – making beneficial changes to the DNA of an organism, such as a plant or animal.

The researchers who produced Dolly were working on cloning as a method of producing genetically modified livestock for research.

The advance, carried out by a team from Roslin and PPL Therapeutics, was technically difficult. Dolly was the result of many months of research involving a highly skilled team.

Cloning has since been superseded by other technologies and is no longer carried out at the Roslin Institute.

Dolly the Sheep remains a significant scientific breakthrough, 25 years after her birth. The legacy of Dolly, and the creative spirit of the team involved, continues to inform and inspire researchers in their work, including at the Roslin Institute where we are using gene editing to tackle infectious diseases, food security and pests.

Professor Bruce Whitelaw, Professor of Animal Biotechnology, Roslin Institute

The research behind Dolly the Sheep has helped give rise to developments in editing the genetic codes of organisms, and a route to developing and studying the effects of introducing changes to DNA, which underpins a swathe of ongoing scientific research – including how to mitigate important diseases. These technologies provided the basis for our team to produce gene-edited pigs that are resistant to a deadly virus.

Dr Christine Tait-Burkard, Virologist, Roslin Institute

It is difficult to overstate the significance of Dolly, as the first mammal to be cloned from an adult cell – up until that point, this task seemed impossible. The creation of Dolly inspired and paved the way for later ground-breaking work to generate stem cells, called induced pluripotent stem cells (iPSCs), from adult cells. The use of iPSCs has truly revolutionised biomedical research and our understanding of how cells work. My team is using this knowledge to better understand animal disease and to develop novel therapies for animals.

Dr Xavier Donadeu, Stem Cell Biology researcher, Roslin Institute

Dolly remains highly significant, as the first cloned mammal from an adult cell. It was a privilege to be involved with the renowned team who created Dolly, and they were a great group to work with.

Professor Susan Rhind, Director of Veterinary Teaching, and Pathologist on the Dolly project

Dolly the Sheep was significant not only as a cloned mammal, but because it was research involving a large animal. Since then, large animal studies have become a valuable tool for the understanding of human diseases. By bridging the gap between the research lab and the development of effective therapies and smoothing the path to making drugs available to patients, it also helps to limit the numbers of animals needed for such vital research.

Dr Tom Wishart, Molecular Anatomy Researcher, Roslin Institute


 Source: University of Edinburgh, Roslin Institute



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