Cloned Meat Ruling Sparks Optimism, Outcry in U.S.

A flock of cloned sheep relaxes on a Scottish farm. These sheep—created a year after the world's first cloned mammal, Dolly—lived with the famous ewe until she was euthanized in 2003 after developing a lung infection. Now, ten years after Dolly's debut, scientists have created copies of a barnyard's worth of species, including cats, dogs, goats, and deer—but no humans. Photograph courtesy ViaGen


Cloned Meat Ruling Sparks Optimism, Outcry in U.S.
Maryann Mott
for National Geographic News
January 3, 2007

The announcement last week by the U.S. Food and Drug Administration (FDA) that products from clones are safe to eat has reignited debate over the safety and ethics of animal cloning.
After analyzing hundreds of peer-reviewed publications, the FDA deemed that milk and meat from cloned livestock and their offspring are no different than regular meat and dairy products sold in the U.S.
Gary Weaver, of the University of Maryland Center for Food, Nutrition, and Agriculture Policy in College Park, says cloning technology could improve the overall quality of supermarket products.
"When I buy steaks it's always a gamble," he said. "You can have two that look the same, [but] one is tender and the other is shoe leather."
With cloning "in ten years we might all be eating prime beef for a reasonable price."
Only 3 percent of U.S. beef is currently labeled as prime—the government's highest rating. Such high-quality meats are found mostly in upscale restaurants.
Many consumer groups argue that FDA's evaluation of cloned meats hasn't been thorough enough.
What's more, the groups say, the practice of cloning still raises too many ethical issues, including the possibility that large corporations could patent the genes of food animals.
George Siemon is CEO of the Organic Valley farmers cooperative in LaFarge, Wisconsin, which represents 922 farmers in 27 states.
"Allowing animal cloning … to be patented by profit-driven companies has too many unknown risks," Siemon said. "[It] is a detriment to farmers and the future of our food supply."
Clone Wars
A report with the U.S. government's final say on the controversial issue is expected by the end of this year.
If the government does approve cloned meat for sale, such products wouldn't hit supermarket shelves for at least five years, the University of Maryland's Weaver said.
In total only 600 cloned pigs, cows, and goats are believed to exist right now in the U.S.
Because of their rarity and price—some animals can cost upward of $170,000 (U.S.) each—clones would be mostly used as breeding stock to pass on naturally occurring, desirable traits, Weaver said.
For example, the fat content in beef and pork could be controlled to create healthier meat. The technology could also give rise to disease-resistant cattle (related photo: Kansas cattle).
Despite the FDA ruling, consumer groups argue that scientific evidence that cloned foods are safe for humans remains superficial.
In a statement released just before FDA's announcement, the nonprofit advocacy group the Center for Food Safety in Washington, D.C., cited a number of health and safety problems related to cloned livestock that the group says the agency has not properly addressed.
People eating cloned meat would be exposed to higher amounts of animal hormones related to the cloning process, the group says.
The animals themselves would suffer from the high incidence of disease and birth defects currently recorded in cloned animals.
"There is widespread concern among Americans and scientific concern that cloned food may not be safe and that cloning will increase animal cruelty," Joseph Mendelson, legal director for the Center for Food Safety, said in the release.
"We intend to pursue our legal action to compel FDA to address the many unanswered questions around cloned food."
Mixed Reactions
Meanwhile, Austin, Texas-based ViaGen is one of a handful of U.S. companies already working on livestock clones.
The company has successfully duplicated 250 farm animals in recent years, including individual horses, cows, and pigs.

(Related news: "Ten Years After Dolly, No Human Clones, But a Barnyard of Copies" [July 5, 2006].)

ViaGen president Mark Walton said cloning is just another tool that enables farmers to breed their best animals.
For decades other assisted reproductive technologies have been used in agriculture, such as artificial insemination and in vitro fertilization.
In fact, he said, 90 percent of U.S. dairy cows are produced via artificial insemination and nearly half of the country's beef cattle are born through assisted reproduction.
Though cloning is a hot topic, he said, most people have little understanding of what it is, how it's done, and whether it's useful.
"Unfortunately," Walton said, "those who turn to the popular media for insight about this new breeding technology are as likely to encounter myths as they are to find facts."
So far consumer reaction to cloned foods appears to be mixed, especially in light of the fact that FDA is unlikely to require cloned products to be specially labeled.
A University of Maryland survey released last month found that six out of ten U.S. shoppers would consider buying meat and milk from cloned animals or their offspring if the FDA determined the products were safe.
But a December 2006 survey by the Pew Initiative on Food and Biotechnology, an independent advisory group, found that 64 percent of those polled were uncomfortable with animal cloning.
And a survey conducted by the International Dairy Foods Association last summer found that 14 percent of women shoppers would turn away from all dairy products if milk from clones is introduced into the food supply.
Connie Tipton, president of the Washington, D.C.-based trade group, said it's too soon to know if dairy farmers will embrace cloning.
"There is currently no consumer benefit in milk from cloned cows," she said.



Ten Years After Dolly, No Human Clones, But a Barnyard of Copies
Maryann Mott
for National Geographic News
July 5, 2006

Is she a monster or a miracle?
This was the front-page question posed by Britain's Daily Mail newspaper in 1997.
The article was just one of hundreds of news reports on the world's first cloned mammal, Dolly the sheep.
Born July 5, 1996, at the Roslin Institute in Scotland, Dolly was the genetic copy of a six-year-old Finn Dorset ewe. Because of a patent application on the cloning process, her birth was kept a secret until February 27, 1997.
Researchers, religious leaders, and politicians immediately began debating the ethical implications of cloning mammals.
Specifically, the announcement of a cloned sheep sparked concern that human clones wouldn't be far behind.
The U.S. and British governments both called for reports on the implications of the achievement, while the Vatican urged a worldwide ban on human cloning.
A decade later human clones seem no closer to reality, but scientists have created copies of a barnyard's worth of animals.
In all, 15 wild and domestic species have been copied, including African wildcats, goats, Asian oxen, deer, and even an Afghan hound (photos: world's first cloned dog).
Cloned Dinner?
"It's really astonishing," said Irina Polejaeva, referring to the number of species cloned within the last decade.
Polejaeva is the chief scientific officer for Austin, Texas-based ViaGen—one of several U.S. companies offering commercial cloning services.
Americans can now buy a copy of a beloved cat for $32,000 or a clone of a champion horse for $150,000.
U.S. farmers and ranchers are also plunking down thousands of dollars to duplicate prize bulls, cows, and pigs.
It won't be long before milk from cloned livestock and meat from their offspring arrive on dinner tables, observers say.
Ranchers are waiting for a final report from U.S. Food and Drug Administration (FDA) on whether products of cloned animals are safe to eat. The report is expected sometime this year.
Wayne Pacelle is president of the Humane Society of the United States, based in Washington, D.C. He says commercial cloning is the ultimate in terms of frivolous uses of animals.
"We have gotten along fine for all of human history without relying on cloning and relying on reproduction as a means of procreation," he said.
Barnyard to Nursery
Meanwhile, cloning advocates say that every step of the cloning procedure has improved in the decade since Dolly's birth.
For example, health problems seen in early clones have declined to rates approaching those of other reproductive technologies.
Ian Wilmut led the team that created Dolly and is now a professor at Scotland's University of Edinburgh.
He says that the major cloning accomplishments of the last ten years have involved research projects where precise genetic changes were made to farm animals to benefit human health.
"One was to change pigs so that their organs are more likely to be suitable for transfer into people," he wrote in an email to National Geographic News. (Read "Cloned Pigs Modified for Use in Human Transplants.")
"At present, thousands of people die each year before an organ becomes available."
In 1997 Wilmut's research team unveiled Polly, a sheep altered to secrete a human blood-clotting protein in her milk.
Wilmut has since turned his attention from the barnyard to the nursery.
The geneticist hopes that one day cells derived from cloned human embryos will shed light on how to treat inherited human diseases.
In his new book, After Dolly: The Uses and Misuses of Human Cloning, he argues that cloned human embryos could provide great benefits to healthy reproduction.
When the technology is safe, he writes, scientists should be allowed to combine the cloning of human embryos with genetic modification to prevent the birth of babies with serious diseases.
"I want people to have new options when it comes to the most fundamental urge: to bring healthy children into this world," he writes.
"The use of genetic and reproductive technologies is not a step backwards into darkness but a step forward into the light."
But Wilmut seems unsure if cloning cats for companionship or horses for competitions are legitimate uses of the technology.
"At present many cloned animals die, and mothers have a difficult time giving birth to clones," he said.
"In these circumstances I think that you have to have a really great benefit from any use of cloning."
Goodbye, Dolly
On February 14, 2003, Dolly was euthanized after developing a lung infection.
A postmortem examination confirmed she had arthritis in her hind legs, though no evidence was found to link this ailment or her respiratory illness to the cloning process.
She is now on permanent display at the National Museum of Scotland in Edinburgh.
A flock of Dolly's farm mates, created about a year after Dolly, are healthy and living on a farm in Scotland, reports ViaGen's Polejaeva.
The company now owns the flock and is monitoring their health.



Cloned Pigs Modified for Use in Human Transplants
Bijal P. Trivedi
National Geographic Today
January 3, 2002

Two competing teams have cloned pigs that have been genetically modified to produce organs more suitable for transplantation into humans.
Pig organs are well suited for transplantation; they are approximately the same size as human organs and have similar plumbing, which makes reconnecting blood vessels much easier. Also, the size of pig litters tends to be large and pigs reproduce quickly, raising the prospect of a large supply of "spare" organs.
A problem with using pig organs, however, is that they are coated with sugar molecules that trigger acute rejection in people. Human antibodies attach themselves to these sugar molecules and quickly destroy the newly transplanted pig organ.
To circumvent the rejection, scientists are working to produce pigs that lack the sugar-producing gene.
In a significant step toward that goal, a team of scientists led by Randall Prather of the University of Missouri in Columbia created four cloned piglets in which one copy of the sugar-producing gene was "knocked out" (an organism receives two copies of a gene, one from the mother and one from the father). The piglets were born in September and October. A description of the work was published online by the journal Science.
Earlier this week, PPL Therapeutics PLC of Scotland, the company that helped clone Dolly the sheep, announced the birth of five cloned piglets that also lack a copy of the sugar-producing gene. The piglets were born December 25 and were named Noel, Angel, Star, Joy, and Mary.
By selectively breeding the experimental pigs, both teams of scientists hope to produce pigs lacking both copies of the gene. It's expected that the organs of these modified pigs could be transplanted into people without the problem of tissue rejection.
The new results are a significant advance over many other attempts at genetic modification in animals because in both of the studies, the scientists were able to modify—in this case, "knock out"—a gene at a specific location. Although genes from other organisms have been inserted into the genomes of sheep, cattle, and pigs, scientists have had little control over where on a chromosome the new gene is incorporated.
"This is the first time a specific genetic modification has been made in the pig," said Prather.
Prather's team at the University of Missouri and his colleagues at Immerge BioTherapeutics Inc. in Charlestown, Massachusetts, genetically altered fetal pig cells, which were used to create embryo clones. Of 3,000 genetically modified pig embryos that were implanted into 28 surrogate sows, only seven piglets were born, three of which died later.
The cloning of Dolly almost five years ago raised expectations of creating identical, genetically modified organs for transplantation into humans. The cloning of genetically modified piglets brings scientists closer to their goal of "xenotransplantation"—the transfer of cells and organs from one species into another.
A concern that has dampened the prospects of xenotransplantation is the possibility of spreading viruses from one species to another. Porcine endogenous retrovirus (PERV), for example, is part of a pig's natural genetic makeup and does not cause any disease in the animal. There is no guarantee, however, that PERV would be harmless in humans.
To minimize the risk of spreading PERV, Prather's team used a line of pig—miniature swine—that was developed specifically for the purpose of transplantation. A major advantage of these pigs is that they are unable to spread PERV.
Prather's team expects to produce a miniature swine that lacks both copies of the sugar-producing gene within the next 18 months.