Baaa-d news. Dolly, the cloned sheep, is having an early midlife crisis.
The scientists who created the extraordinary ewe said yesterday some of her DNA is damaged, showing signs of premature aging.
The genetic gaffe could cause problems for Dolly down the road and have an impact on how cloning technology is used in the future.
“We don’t see any signs of any problem in Dolly and the other animals, but perhaps it is too early to note such a problem,” researcher Alan Colman said.
“We just don’t know.”
Dolly became the world’s first cloned mammal when Scottish scientists created her from the cell of a 6-year-old sheep two years ago.
Now the researchers have found irregularities in the telomeres, the tiny strands of DNA at the end of the carbon copy’s chromosomes.
Telomeres shorten as an animal ages, a process that can lead to damaged chromosomes.
Since Dolly was cloned from a middle-aged sheep, her telomeres were short from the start.
In addition, the culturing of cells in a laboratory – the process used to spawn Dolly and other sheep – truncates the DNA strands.
The findings highlight the possible hazards of one day using adult cells to create cloned tissue and organs to conquer diseases such as Parkinson’s and Alzheimer’s.
“It reminds people this is an issue that should be called into account in any of the proposals for, not so much agricultural cloning, but some of the uses in human therapeutic cloning,” Colman said.
“Human therapeutic cloning, if it ever does come about, is going to use human adult cells. That’s the whole purpose.”