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Background: Cloned and Genetically Modified Animals

April 14th, 2005

Several animal species have already been genetically modified, and at least eleven have been cloned, though some scientists doubt the health of those clones that survived to birth.

Some of these efforts are commercial, either for agribusiness or for sale directly to consumers as pets. Others are scientific experiments, usually defended as advancing, directly or indirectly, the cause of medicine for humans.

The cloning or genetic modification of pets serves no justifiable purpose. These efforts serve only to play upon one set of emotions-our affection for our companion pets-in order to desensitize another set of emotions-our repugnance at the idea of treating them as artifacts that can be "designed" and manufactured.

The modification of livestock and the possibility of cloned meat entering the food chain are very controversial. So is the possible use of genetically modified animals to "grow" either pharmaceutical products or organs for transplant into humans.


There have been published reports of the following species being cloned: carp, sheep, mice, cattle, goats, pigs, cats, rabbits, mules, horses, rats, and a deer. Some closely related species have also been cloned (a banteng, a wild cow, and a mouflon, a kind of sheep). A gaur, a wild ox, was cloned but died within two days.

Attempts have also been made, without success, to clone monkeys, dogs, pandas, chickens, and at least two extinct species: the Tasmanian tiger and the woolly mammoth. The mammoth experiment used an elephant surrogate and tissue found in permafrost.

Three major British institutions announced in July 2004 that they were setting up a tissue bank to preserve the DNA of endangered species, even after their extinction. Future cloning is seen as a possibility.

The Roslin Institute, where the first mammal was cloned, maintains records of all published mammalian cloning experiments up to July 2002 - 50 papers detailing 68 experiments, with 386 surviving clones. They conclude that the "overall efficiency of cloning is typically between 0 and 3% (number of live offspring as a percentage of the number of nuclear transfer embryos), irrespective of the species, the donor cell type or technique." There is no evidence that efficiency has significantly improved since.

Cloning for livestock

About 300 bulls have been cloned, with the aim of improving the quality of breeding stock. Cloning is too expensive, at around $20,000 per bull, to clone directly for meat, but breeding bulls are worth much more than that.

The meat and milk of cloned cattle is presently kept off the market pending FDA approval. Nevertheless, BIO is actively promoting the use of cloned and transgenic animals for human food, as well as for pharmaceuticals.

The FDA is investigating the possibility of selling meat from cloned pigs as well as cattle, and in 2003 released a draft executive summary well in advance of the report it was supposed to summarize. "The FDA wants to gauge public reaction to the prospect of food from cloned farm animals before it decides whether to require government approval of the products before they are sold. That decision is expected to take another year."

Pet cloning

In 1998 Arizona billionaire John Sperling gave $3.7 million to Texas A&M University to clone his pet dog, Missy (the "Missyplicity Project"). Sperling is controversial. He became wealthy as founder of the University of Phoenix, a distance learning university that has been accused by many of being a "diploma mill." He has since used his assets to support a number of idiosyncratic endeavors.

The dog-cloning effort failed, and the team, reportedly against Sperling's wishes, began parallel efforts to clone a cat. The birth of the first cloned domestic cat was announced by the Texas A&M research team in February 2002. Born on December 22, 2001, "CopyCat" or "CC" was produced by fusing an ovarian tissue cell from an adult cat with a cat egg, and implanting the clonal embryo into an adult cat. This cloning "success" occurred after 188 failed attempts.

Sperling retained Lou Hawthorne, a publicist from Marin County, California, to handle public relations for his dog-cloning effort. Hawthorne subsequently established "Genetic Savings & Clone" as a profit-making venture to provide pet cloning services

The company is offering to clone cats for $50,000. They also offer "gene banking" services for up to $1395, plus up to $150/year, all of which can be credited against the future cost of cloning. They announced in April 2004 that five customers had paid the fee, work had already begun on three other cats for staff members and one more slot was available, to make "nine lives."

They hope to increase production to several thousand a year, and to reduce the cost substantially.

Genetic Modification

Science, mice, and patents

The most commonly genetically modified animal is almost certainly the mouse. It is small, short-lived and sufficiently similar to humans to be an almost ideal laboratory animal. As a result, mice have not only been cloned and modified, they have led to an actual industry in the production of "knockout mice," that is, mice with a particular gene or set of genes inactivated for research purposes.

Trans Genic Inc asserts, "Currently, we are able to produce almost 1,000 strains of Knockout mouse in a year."


Cattle, sheep, goats, chickens, rabbits and pigs have been genetically modified with the aim of producing human proteins that are useful, generally as medicines. The gene transfer process is typically very inefficient, and cloning is seen as another way of propagating the GM animal.

A 1999 USDA report cited estimates that there was a $24 billion market for human proteins, and theoretically 600 transgenic cows could supply the worldwide demands for some drugs. In practice, however, several companies that have pursued this line have gone bust, and the profit potential seems less than it once did.

Genetic modification of animals in order to improve the prospects of organ transplants is also being investigated.

Genetically modified fish as pets

A tropical fish genetically modified to glow in the dark went on sale in Taiwan in 2003 for about $17 each. A different variety of zebrafish, called "GloFish," which were created in Singapore, reached the United States market in January 2004. The distributor says that GloFish were originally developed to fluoresce only in the presence of pollutants, but that is not the form in which they are being sold. They cost about $5 each, and are intended to live in aquariums, but can breed and, in the right conditions, live in the wild.

The Food and Drug Administration (FDA) approved the sale without ceremony. A coalition led by the Center for Food Safety filed suit against the decision, but sales went ahead. In California, the Fish and Game Commission initially banned the fish but later agreed to hold hearings at the request of the distributor.

Allergy-free cats?

A company called Transgenic Pets, in Syracuse, NY, was widely reported in 2001 to be working with scientists at the University of Connecticut to "remove the allergen gene" from cats. The company hoped to raise $2 million and sell the modified animals for $1,000 each. Funding problems ended the project.

Genetic modification for aquaculture

Most discussion of bioengineered food focuses on plants, but work on animals and fish is well under way. Genetically modified salmon have already been created, though FDA approval is not expected before at least 2006 and the target date has repeatedly been delayed. The Biotechnology Industry Organization (BIO) and the developers, Aqua Bounty Farms, claim that the GE salmon grow faster but not larger than ordinary salmon, but this is strongly disputed. Opponents also cite studies showing dramatic population crashes and unpredictable environmental impacts.

Salmon are not the only fish species being modified. Acting FDA Commissioner Lester M. Crawford summarized the position in a speech given in March 2004:

"Less well known is that catfish and tilapia have been also genetically modified to grow faster and more efficiently than their non-transgenic counterparts. Rainbow trout has been engineered to increase its contents of omega 3 fatty acids, and shellfish is being modified to reduce its allergenicity and make it grow faster."

The matter-of-fact, if not approving, tone of these comments is disturbing, as it comes from the head of the agency that is supposed to be regulating these technologies.

Other countries, including Canada, have moved much faster than the United States to ban or at least place a moratorium on the genetic modification of fish. Malcolm Grant, Chair of the UK Agriculture and Environment Biotechnology Commission, points out that

"Once the fish has escaped, there's virtually nothing that can be done to recall it... Genetic biotechnology has opened a new chapter in the relationship between man and animals. We must therefore prepare now for developments that may be many years away."

He also argues that pet cloning is "trivial, distasteful and could be sold to gullible owners."
Genetically modified farm animals

Acting Commissioner Crawford continued:

"Cows can be bioengineered to produce several varieties of milk: milk with a lower level of a protein that's allergenic to some infants; milk that is more easily digested by people who are lactose intolerant; milk that has more naturally occurring antimicrobial enzyme, and therefore has longer shelf life; and milk that makes better cheese because it has altered distribution of caseins or less fat."

Genetic modification for livestock

Research is also underway to use genetic modification to improve the health of cows and pigs. Advocates hope to produce cattle that would be resistant to Mad Cow disease, for example.

There have also been reports of cows being genetically modified to "produce milk with higher than normal levels of protein, which would speed the process of making cheese."


Some researchers have created embryos with genetic material from both a human and an animal, also known as chimeras. Most claim this is for research purposes only, and such embryos would never be implanted or brought to term. But some bioethicists are unwilling to draw a line that would prevent it. For example, Jason Scott Robert and Francoise Baylis assert that they take "no stance at all" on whether "interspecies hybrids or chimeras from human materials should be forbidden or embraced." But much of their article is devoted to their contention that "the arguments against... creating novel part-human beings... are largely unsatisfactory."

The prospect of such human-animal chimeras being born raises a number of troubling questions. Does such an organism have human rights? What if it were 99.9% human and 0.1% chimpanzee? What of the reverse situation?

The mixing of species can occur at three different levels. First, some DNA from one organism can be inserted into another organism's genome. Most often, however, these are described as transgenic animals rather than chimeras. For example, scientists have produced transgenic mice which contain some human genes.

Another type of chimera involves a blastocyst containing components from multiple species. James Grifo has used this technique for fertility research. After the US federal government informed him he could no longer continue his experiments, his team moved to China. There, they removed the nucleus from a fertilized rabbit egg and inserted a nucleus from a human somatic cell. The resulting embryos, which still contained rabbit mitochondrial DNA, were allowed to grow for 14 days before destruction.

Finally, scientists have placed cells from one species, typically human stem cells, into a multicellular embryo of another species. In 2004, researchers were surprised to discover that injecting human stem cells into a pig embryo resulted in a fetus whose cellular components were intermingled down to the genetic level. Many cells contained chromosomal DNA of both pig and human origin.


Several environmental and animal rights organizations have expressed opposition to pet cloning, including Friends of the Earth and the Humane Society of the United States, the largest animal welfare organization in the country.

Jeremy Rifkin from the Foundation on Economic Trends and Stuart Newman of the New York Medical College and the Council for Responsible Genetics have pursued a novel path of opposition. They filed a patent application with the US Patent and Trademark Office for chimeric embryos and animals containing human cells. They did not intent to create a "humouse." Instead, they tried to force the PTO to take a position and, if the patent is granted, to prevent chimeras from being developed.


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