Dolly was part of a series of experiments at the Roslin Institute, part of the University of Edinburgh in Scotland, that were trying to develop a better method for producing genetically modified livestock. If successful, this would mean fewer animals would need to be used in future experiments. Scientists at Roslin also wanted to learn more about how cells change during development and whether a specialized cell, such as a skin or brain cell, could be used to make a whole new animal.
|Dolly the Sheep, the world’s first cloned mammal, is shown in this undated photo. (Photo: Getty Images)|
|Dolly, center, was the world’s first cloned sheep. Dolly was located at the Roslin Institute in Scotland. (Photo: Karen Kasmauski/Getty Images)|
Dolly was cloned by Keith Campbell, Ian Wilmut and colleagues at the Roslin Institute and the biotechnology company PPL Therapeutics, based near Edinburgh. The funding for Dolly’s cloning was provided by PPL Therapeutics and the Ministry of Agriculture. She was born on July 5, 1996 and died from a progressive lung disease five months before her seventh birthday (the disease was not considered related to her being a clone) on February 14, 2003. She has been called “the world’s most famous sheep” by sources including BBC News and Scientific American.
Although Dolly was born in July 1996, researchers announced Dolly’s existence on February 22, 1997. The delay in the announcement was due to the time needed to amass sufficient data on the project, check the data, write and get the manuscript published.
|Dolly meets the world’s media. (Photo: Murdo Macleod)|
On Dolly’s name, Wilmut stated “Dolly is derived from a mammary gland cell and we couldn’t think of a more impressive pair of glands than Dolly Parton’s.”
Dolly had three mothers: one provided the egg, another the DNA, and a third carried the cloned embryo to term. She was created using the technique of somatic cell nuclear transfer, where the cell nucleus from an adult cell is transferred into an unfertilized oocyte (developing egg cell) has had its cell nucleus removed. The hybrid cell is then stimulated to divide by an electric shock, and when it develops into a blastocyst it is implanted in a surrogate mother.
Dolly was the first clone produced from a cell taken from an adult mammal. The production of Dolly showed that genes in the nucleus of such a mature differentiated somatic cell are still capable of reverting to an embryonic totipotent state, creating a cell that can then go on to develop into any part of an animal.
|Dolly in 1997 on the right. Her penmate is Polly, a sheep genetically engineered by the team at Roslin. (Photo: John Chadwick/AP)|
|Dolly the Sheep with her first born lamb, called Bonnie. (Photo: The Roslin Institute/The University of Edinburgh)|
|Dolly as a lamb with her surrogate mother. (Photo: The Roslin Institute/The University of Edinburgh)|
Dolly wasn’t the first animal to be cloned—research on cloning had been going on since the mid-20th century—but she was the first example of successful cloning of a mammal from an adult cell, rather than a more malleable embryo. Getting there wasn’t easy, nor was it easy for laypeople to understand how the Scottish team succeeded.
After her death in February 2003, the Roslin Institute donated Dolly’s body to the National Museum of Scotland in Edinburgh, where she has become one of the museum’s most popular exhibits. Dolly is back on display in the museum after an extensive gallery refurbishment, alongside an interactive exhibit on the ethics of creating transgenic animals featuring current research from the Roslin Institute.