Home / Lists / Dolly the Sheep: media sensation of the 90s

Dolly the Sheep: media sensation of the 90s

It was Saturday, February 22nd, 1997, and Scottish researchers Ian Wilmut and Keith Campbell awaited a final moment of calm before the results of their unprecedented scientific experiment were announced to the world.

The team had kept the breakthrough under wraps for seven months while waiting for their article to appear in the prestigious magazine nature. Confidential press releases had been sent to journalists with strict instructions not to publish the news before February 27.

But that night, the team was advised that journalist Robin McKie would publish the story in the UK newspaper the next day The Observer.

Wilmut and Campbell ran to the lab at the Roslin Institute on Sunday morning when McKie̵

7;s story hit the media like lightning. International news agencies had already started looking at the institute for access to Wilmut’s and Campbell’s creation: Dolly, the sheep, the world’s first mammal to be successfully cloned from a single adult cell. Protected from the public, she stuck her nose through the fence and quietly chewed the hay in her pen, unmoved by the horde of news photographers. Dolly, a woolly, bleating scientific marvel, looked very much like other sheep, but with a notable genetic difference.

At the end of that Sunday, February 23rd, almost every major newspaper in the world made headlines about Dolly the Sheep.

A long awaited breakthrough

Born on July 5, 1996, Dolly was cloned by Wilmut and Campbell’s team at the Roslin Institute, part of the University of Edinburgh, and the Scottish biotechnology company PPL Therapeutics. Scientists cloned Dolly by inserting DNA from a single mammary gland cell from one sheep into an egg from another sheep and then implanting it in a surrogate ewe. So Dolly had three mothers – one who supplied the DNA from the cell, the second who supplied the egg, and the third who carried the cloned embryo. Technically, however, Dolly was an exact genetic replica of just the sheep the cell came from.

According to the announcement, the Roslin Institute received 3,000 calls from around the world. Dolly’s birth has been heralded as one of the most important scientific advances of the decade.

But Dolly wasn’t science’s first attempt at cloning. Researchers had studied the intricacies of cloning for nearly a century. In 1902, the German embryologists Hans Spemann and Hilda Mangold, his student, successfully bred two salamanders from a single embryo that was split from a strand of hair with a loop. Since then, the cloning experiments have become more sophisticated and nuanced. Several laboratory animal clones were created prior to Dolly, including frogs and cows. But all of them had been cloned from embryos. Dolly was the first mammal to be cloned from a specialized adult cell.

Embryonic stem cells, which form immediately after fertilization, can transform into any type of cell in the body. After they transform into certain types of cells, such as neurons or blood cells, they are called specialized cells. Since the cell that Dolly emerged from was already specialized in its role as a mammary cell, most scientists thought it impossible to clone anything other than other mammary cells from it. Dolly proved them wrong.

A worldwide reaction – and controversy

Many scientists in the 1990s were baffled. Dolly’s advent showed that specialized cells could be used to create an exact replica of the animal they came from. “It means that all science fiction is true,” said Princeton University biology professor Lee Silver The New York Times in 1997.

The Washington Post reported that “Dolly, depending on which commentator you read, is the greatest story of the year, the decade, even the century. Wilmut has compared himself to Galileo, Copernicus, Einstein, and at least once to Dr. Frankenstein.” “

Scientists, lawmakers, and the public quickly envisioned a future shaped by unethical human cloning. President Bill Clinton called for a review of the bioethics of cloning and proposed laws banning cloning, which means “for the purpose of creating a child” (it failed). The World Health Organization concluded that human cloning is “ethically unacceptable and contrary to human integrity and morals”. [PDF]. An editorial in the Vatican newspaper urged governments to ban human cloning. Everyone has “the right to be born in a human way and not in a laboratory”.

In the meantime, some scientists were not convinced of the authenticity of Wilmut and Campbell’s experiment. Norton Zinder, professor of molecular genetics at Rockefeller University, called the study, published in Nature, “bad paper” because Dolly’s genetic lineage was inconclusive without testing her mitochondria – DNA passed down from mothers. That would have confirmed whether Dolly was the daughter of the sheep that gave birth to them. in the The New York TimesZinder called the Scottish couple’s work “just lousy science, incomplete science”. “But NIH director Harold Varmus said that Times that he had no doubt that Dolly was a clone of an adult sheep.


Because she was cloned from a breast cell, Dolly was named after the buxom country superstar Dolly Parton. (Parton didn’t mind the attribution.) Like her namesake, Dolly the Sheep was a real celebrity: she posed for magazines, including People;; became the subject of books, magazine articles and editorials; had written an opera about her; starred in commercials; and served as a metaphor in an election campaign.

And that wasn’t all: New York Times Reporter Gina Kolata, one of the first journalists to give readers a detailed look at Dolly, wrote Clone: ​​The way to the dolly and the way ahead of us and contrasted the creation of the beast with the archetypes in Frankenstein and The island of Dr. Moreau. The American composer Steve Reich was so affected by Dolly’s story that he introduced her in the story Three stories, a video opera that explores the dangers of technology.

The sheep also became an unintended political gambler when the Scottish National Party used her image on posters to indicate that other party candidates were all clones of each other. Device manufacturer Zanussi used her character on a poster with her name and the provocative headline “The Misappliance of Science” (the poster was later withdrawn after scientists complained). In fact, the (mis) use of her name was so widespread that her makers eventually used it as a trademark to end the practice.

Dolly’s legacy

After Dolly, many larger mammals were cloned, including horses and bulls. Roslin Biomed, founded by the Roslin Institute to focus on cloning technology, was later sold to the US-based Geron Corporation, which combined cloning technology with stem cell research. Despite her popularity – and widespread fear – Dolly’s birth did not result in an explosion in cloning: human cloning was viewed as too dangerous and unethical, while animal cloning was minimally useful for agricultural purposes. The true heritage of the sheep is seen as an advancement in stem cell research.

Dolly’s existence showed that it was possible to change the gene expression of one cell by exchanging its nucleus for another. Stem cell biologist Shinya Yamanaka said Scientific American that Dolly’s cloning motivated him to successfully develop stem cells from adult cells. He later won a Nobel Prize for his results, known as Induced Pluripotent Stem Cells (iPS) because they are man-made and can have a variety of uses. They reduced the need for embryonic stem cells in research, and today iPS cells form the basis of most stem cell research and therapies, including regenerative medicine.

Dolly had six offspring and led a productive, sociable life with many human fans visiting. In 2003, a veterinary exam found that Dolly had progressive lung disease and was knocked out. However, four clones made from the same cell line in 2007 had no such health problems and had aged normally.

Dolly, however, is still a spectacle nearly 25 years after its inception: her body has been taxidermized and on display at the National Museum of Scotland in Edinburgh.

Source link