Dolly The Sheep

Risa Martignon

Published: 27/02/2024

This quotation is always the best way to summarise exactly what Dolly’s story is about. Dolly the Sheep’s cloning marked an important event in scientific history, with the techniques used being stepping stones for subsequent research and discoveries. At the same time, the ethical debates brought forward issues such as animal rights.

So, how exactly was the cloning itself done? Dolly was created using Somatic Cell Nuclear Transfer (known as SCNT). This name is actually a very descriptive and accurate one, as the main idea is transferring the nucleus of a donor somatic cell into an egg cell (3). To simplify this whole idea, here’s a step-by-step explanation (4):

Scientists isolate a somatic cell from the mammary gland of an adult sheep.
The nucleus, which has the DNA, is removed from the somatic cell.
An egg cell is taken from another sheep and the nucleus is again removed
Scientists isolate a somatic cell from the mammary gland of an adult sheep.
The nucleus, which has the DNA, is removed from the somatic cell.
An egg cell is taken from another sheep and the nucleus is again removed.

Fig. 1 (1)
“The cloning of Dolly the sheep has widely been described as one of the most important scientific events of the last century, comparable to the splitting of the atom, the discovery of DNA, and the elimination of smallpox.” (2)

This is more clearly illustrated in Figure 1

Extracting the mammary cells from the Finn Dorset ewe for Dolly ended with the ewe being killed (5). Then another sheep was used for culturing the cell at the start of embryo development and had 2 surgeries, the latter of which ended with her also being killed. The other 2 sheep involved were treated with different chemicals, surgeries and therapies: obviously, sheep cannot give consent and certainly cannot give informed consent.

However, this is just one of the many ethical concerns and wasn’t even the major one.

Are scientists ‘playing G-d’? Is it ethically okay to even develop this technology, which is then further used in genetic modification? How close is that to actual eugenics? Who has the right to decide whether this is okay? The public, the scientific community, the politicians?

You can see the many problems with this type of research - these concerns weren’t new by any means, but with Dolly in the public eye, they were amplified. With science advancing in leaps and bounds, this quotation is even more relevant: ‘Until recently, the main limits were technical: what it is possible to do. Now scientists are faced with ethical limits as well: what it is acceptable to do.’ (6)

The problem is now even more complex, as we consider the possible applications of cloning.

There are 7 ‘main’ ways this technology can be used for the better (7), but I will just briefly outline xenotransplantation and genetic conservation.

Genetic conservation and species running extinct have been a large problem, so let’s briefly look at the Ovis Orientalis Musimon, who was cloned using post-mortem cells (8) (note that as they are post-mortem, some of the previous ethical issues are also neatly irrelevant). This study from 2001, led by Dr Pasqualino Loi, concluded that ‘Our findings support the use of cloning for the expansion of critically endangered populations’. (9)

(1). Heaf, David. "The Cloning of Dolly the Sheep." New View, 3rd.

(2). Franklin, Sarah. "Dolly the world-famous sheep." & LARRETA, ER (Ed.) Identity and Difference in the Global Era. Rio de Janeiro: Unesco, ISSC, Educam (2002)

(3) Wilmut, Ian, Yu Bai, and Jane Taylor. "Somatic cell nuclear transfer: origins, the present position and future opportunities." Philosophical Transactions of the Royal Society B: Biological Sciences 370.1680 (2015): 20140366..

(4). Heaf, David. "The Cloning of Dolly the Sheep." New View, 3rd.

(5)Lassen, Jesper, et al. “After Dolly—Ethical Limits to the Use of Biotechnology on Farm Animals.” Theriogenology, vol. 65, no. 5, Mar. 2006, pp. 992–1004.

(6). Heaf, David. "The Cloning of Dolly the Sheep." New View, 3rd.

(7). Griffin, H. D. Dolly: the science behind the world's most famous sheep. No. OPEN-2000-262. Cern, 1999..

(8-9). Loi, Pasqualino, et al. "Genetic rescue of an endangered mammal by cross-species nuclear transfer using post-mortem somatic cells." Nature biotechnology 19.10 (2001): 962-964.

Dolly The Sheep

Scientists isolate a somatic cell from the mammary gland of an adult sheep.

The nucleus, which has the DNA, is removed from the somatic cell.

An egg cell is taken from another sheep and the nucleus is again removed

Scientists isolate a somatic cell from the mammary gland of an adult sheep.

The nucleus, which has the DNA, is removed from the somatic cell.

An egg cell is taken from another sheep and the nucleus is again removed.

Fig. 1 (1) “The cloning of Dolly the sheep has widely been described as one of the most important scientific events of the last century, comparable to the splitting of the atom, the discovery of DNA, and the elimination of smallpox.” (2)

This is more clearly illustrated in Figure 1

Fig. 1 (1)
“The cloning of Dolly the sheep has widely been described as one of the most important scientific events of the last century, comparable to the splitting of the atom, the discovery of DNA, and the elimination of smallpox.” (2)