Dolly the Sheep

In the mid 1990s, many people thought of cloning as only being part of science fiction stories and movies. However, the success of a Scottish team from the Roslin Institute brought the idea to reality with the introduction of Dolly the Sheep, an animal that was the first mammal to be successfully cloned. The somatic cell transfer that enabled the creation was a new process that had yet to find success with complex types of animals. The specific cell used for the cloned sheep was from the mammary gland of an adult sheep. It is because of this somewhat strange origin that the sheep received the name of Dolly, which was a reference to Dolly Parton, a popular entertainer that is famous for the size of her breasts.

The birth of Dolly the Sheep took place in 1996 and the animal lived for a total of seven years. During her life, she stayed at the Roslin Institute to be observed by the researchers responsible for her creation. Most of her life was typical for a sheep and she had a total of 6 offspring that were healthy. While Dolly the Sheep was five years old, she started having problems with arthritis, a condition that happens on a frequent basis with sheep. Drugs were given to the sheep to control the inflammation and the condition disappeared.

While the emergence of Dolly the Sheep is clearly a step towards cloning humans and other complex mammals, there have been few larger animals that have had successful cloning experiments completed. Of these, some cloned animals like bulls and other sheep varieties responded well to the process, but many other species were failures. The developer of the somatic cell transfer method that was used to create Dolly has said that the procedure will probably never work for human cloning in the future.