mrz
16-02-03, 01:53
Dolly the sheep dies young
17:56 14 February 03
NewScientist.com news service
Dolly the sheep, the first mammal to be cloned from an adult cell, was put down on Friday afternoon, after developing a progressive lung disease.
Dolly's birth six-and-a-half years' ago caused a sensation around the world. But as many sheep live to twice this age, her death will refuel the intense debate over the health and life expectancy of cloned animals.
The type of lung disease Dolly developed is most common in older sheep. And in January 2002, it was revealed that Dolly had developed arthritis prematurely. She was cloned using a cell taken from a healthy six-year-old sheep, and was born on 5 July 1996 at the Roslin Institute, Edinburgh, Scotland.
The Institute's Harry Griffin says: "Sheep can live to 11 or 12 years of age. A full post mortem is being conducted and we will report any significant findings". Following the post mortem, Dolly will be donated to the National Museum of Scotland in Edinburgh, where she will be stuffed and put on display.
Some cloned mammals, including Dolly, have shorter telomeres than other animals of the same age. These are pieces of DNA that protect the ends of chromosomes and research has shown that they act as molecular clocks, governing the process of ageing in cells.
There have been contradictory studies on the lifespan of cloned animals. In November 2001, US cloning company Advanced Cell Technology (ACT) said a detailed investigation of 24 calf clones revealed that all were normal.
But a study of cloned mice conducted in February 2002 by researchers at the National Institute of Infectious Diseases in Tokyo, Japan, found that they had a shorter lifespan than normal mice.
On 2 February 2003, Australia's first cloned sheep died unexpectedly at the age of two years and 10 months. The cause of death is unknown and the carcass was quickly cremated, as it was decomposing.
Will Knight
http://www.newscientist.com/news/news.jsp?id=ns99993393
17:56 14 February 03
NewScientist.com news service
Dolly the sheep, the first mammal to be cloned from an adult cell, was put down on Friday afternoon, after developing a progressive lung disease.
Dolly's birth six-and-a-half years' ago caused a sensation around the world. But as many sheep live to twice this age, her death will refuel the intense debate over the health and life expectancy of cloned animals.
The type of lung disease Dolly developed is most common in older sheep. And in January 2002, it was revealed that Dolly had developed arthritis prematurely. She was cloned using a cell taken from a healthy six-year-old sheep, and was born on 5 July 1996 at the Roslin Institute, Edinburgh, Scotland.
The Institute's Harry Griffin says: "Sheep can live to 11 or 12 years of age. A full post mortem is being conducted and we will report any significant findings". Following the post mortem, Dolly will be donated to the National Museum of Scotland in Edinburgh, where she will be stuffed and put on display.
Some cloned mammals, including Dolly, have shorter telomeres than other animals of the same age. These are pieces of DNA that protect the ends of chromosomes and research has shown that they act as molecular clocks, governing the process of ageing in cells.
There have been contradictory studies on the lifespan of cloned animals. In November 2001, US cloning company Advanced Cell Technology (ACT) said a detailed investigation of 24 calf clones revealed that all were normal.
But a study of cloned mice conducted in February 2002 by researchers at the National Institute of Infectious Diseases in Tokyo, Japan, found that they had a shorter lifespan than normal mice.
On 2 February 2003, Australia's first cloned sheep died unexpectedly at the age of two years and 10 months. The cause of death is unknown and the carcass was quickly cremated, as it was decomposing.
Will Knight
http://www.newscientist.com/news/news.jsp?id=ns99993393