We're All Mammals part II

On Sunday, February 23, 1997 scientists in Scotland announced they had cloned an adult mammal, producing a lamb named Dolly.

It gained much attention in the media. A commercial with Scottish scientists playing with sheep was aired on TV, and a special report in TIME Magazine featured Dolly the sheep. Science featured Dolly as the breakthrough of the year. Even though Dolly was not the first animal to be cloned, she gained this attention in the media because she was the first to be cloned from an adult cell.

Dolly (5 July 1996 – 14 February 2003) was a female domestic sheep, and the first mammal to be cloned from an adult somatic cell, using the process of nuclear transfer. She was cloned by Ian Wilmut, Keith Campbell and colleagues at the Roslin Institute and the biotechnology company PPL Therapeutics near Edinburgh in Scotland. The funding for Dolly's cloning was provided by PPL Therapeutics and the Ministry of Agriculture. She was born on 5 July 1996 and she lived until the age of six, at which point she died from a progressive lung disease.

 She has been called "the world's most famous sheep" by sources including BBC News and Scientific American. The cell used as the donor for the cloning of Dolly was taken from a mammary gland, and the production of a healthy clone therefore proved that a cell taken from a specific part of the body could recreate a whole individual. 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".

Birth

Dolly was born on 5 July 1996 to three mothers (one provided the egg, an other 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) that has had its 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's existence was announced to the public on 22 February 1997. It gained much attention in the media. A commercial with Scottish scientists playing with sheep was aired on TV, and a special report in TIME Magazine featured Dolly the sheep. Science featured Dolly as the breakthrough of the year. Even though Dolly was not the first animal to be cloned, she gained this attention in the media because she was the first to be cloned from an adult cell.

Life

The cloning process that produced Dolly

Dolly lived her entire life at the Roslin Institute in Edinburgh. There she was bred with a Welsh Mountain ram and produced six lambs in total. Her first lamb, named Bonnie, was born in April 1998. The next year Dolly produced twin lambs Sally and Rosie, and she gave birth to triplets Lucy, Darcy and Cotton in the year after that. In the autumn of 2001, at the age of four, Dolly developed arthritis and began to walk stiffly, but this was successfully treated with anti-inflammatory drugs.

Death

On 14 February 2003 (yes, on Valentines Day 10 years ago), Dolly was euthanised because she had a progressive lung disease and severe arthritis. A Finn Dorset such as Dolly has a life expectancy of around 11 to 12 years, but Dolly lived to be only six years of age. A post-mortem examination showed she had a form of lung cancer called Jaagsiekte, which is a fairly common disease of sheep and is caused by the retrovirus JSRV. Roslin scientists stated that they did not think there was a connection with Dolly being a clone, and that other sheep in the same flock had died of the same disease. Such lung diseases are a particular danger for sheep kept indoors, and Dolly had to sleep inside for security reasons.

Promised to the National Museums of Scotland (NMS), Dolly is now on display - drawing visitors from all over the world.