On 22 February 1997, 65 years later, scientists in Scotland introduced a lamb named “Dolly” to the world; she was the first mammal to be cloned from an adult cell. Scientists can use cloning techniques to make an exact genetic copy of a living thing.
Dolly was part of a series of experiments at The Roslin Institute that were trying to develop a better method for producing genetically modified livestock… Dolly was cloned from a cell taken from the mammary gland of a six-year-old Finn Dorset sheep and an egg cell taken from a Scottish Blackface sheep.
Dolly was born 05 July 1996; her white face marked her as a clone. Had she been related to her surrogate mother, she would have had a black face.
The Institute had previously cloned sheep from embryos. Dolly was a “lucky accident.”
“We didn’t set out to clone adult cells. We set out to work with—ideally—embryonic stem cells or things like that,” Ian Wilmut says. “Being successful with adult cells was a very considerable, unexpected bonus.”
Researchers were exploring cloning as a method of introducing changes in a breed that would take several generations using traditional methods.
One recent example is introducing the polled (no horns) gene into dairy cattle, thus eliminating the need for the painful process of dehorning. An even more striking application has been to produce a strain of pigs that is incapable of being infected by the very contagious and debilitating PRRS virus. Researchers have even made cattle that cannot develop Mad Cow Disease. For each of these procedures, somatic cell nuclear transplantation is an essential part of the process.
In 2008, the U.S. Food and Drug Administration (FDA) approved consumption of meat and milk from cloned cows, pigs and goats. FDA found no significant differences between healthy clones and healthy animals from conventional breeding.
In 2012, stem cell biologist Shinya Yamanaka won a Nobel Prize for his work developing stem cells derived from adult cells. He credited the work that led to Dolly’s cloning as inspiration.
In 2015, the EU Parliament banned cloning of farm animals.
In 2020, scientists created a foal from frozen cells taken from a Przewalski’s horse stallion. The cells had been stored at the San Diego Zoo for 40 years; scientists joined them with an egg from a domestic horse.
Conservationists report that the species is extinct in the wild, and only an estimated 2,000 individuals remain in zoos and reserves.
Other wild species that been successfully cloned includes the coyote, the African wildcat and a rare Southeast Asian cow.
The outlook for cloned humans? Dim.
📷 Adobe Stock Photo, sheep in New Zealand