# data[].attributes.attachment_link.readable_text
French scientists raised fresh fears today about the dangers of cloning humans, saying it may cause serious long-term health problems.

Researchers at France's Institut National de la Recherche Agronomique said a cow they cloned with DNA from an adult somatic cell appeared healthy but died from anaemia at seven weeks.

They believe the animal, whose immune system did not develop properly after birth, died because of errors in its DNA genetic reprogramming during the cloning process.

"This is the first report of a long-lasting defect associated with somatic cloning," Dr Jean-Paul Renard and his colleagues said in a report in The Lancet medical journal.

"Our observation should be taken into account in debates on reproductive cloning in human beings."

Reprogramming Cells

Cloning animals from adult somatic cells, which make up most of the body, is difficult because the DNA from the adult cells need to be reprogrammed, or set back to their embryonic state. The French cow was cloned from a cell taken from the ear of an adult cow that was an embryonic clone.

Renard and his team suspect something went wrong in the cloning process that interfered with the clone's genetic reprogramming which stopped its immune system from developing.

When the cow died there was no evidence of infection or malformation but a post-mortem examination showed the spleen and lymph nodes had not formed properly.

Scientists at Edinburgh's Roslin Institute, where Dolly the sheep was cloned, described the French study as probably the most detailed investigation of cloned animals.

Scientist Says It's a Bad Sign

"It should be viewed as an important contribution to the evidence that nobody should be contemplating cloning human beings," Dr Harry Griffin, Roslin's assistant director, said in a telephone interview.

"All those that are working in this field know that the technology is unsafe. We have been working hard to get this point over to people speculating about the possibility of using it in cloning of human beings."

The ethical issues of cloning humans have been hotly debated in the media hype that followed the birth of Dolly and other cloned mammals, but the discussions have paid less attention to the medical risks.

All the cloning groups around the world have produced cloned animals that died before or shortly after birth. Griffin said reprogramming could account for the very low success rate of the technique and the immature development of tissues, in this case the immune system.

"The reality is we know very little about the reprogramming process and we are going to have to work hard on that in order to ensure acceptable developments of this technology come to fruition," he said.

The reprogramming of the somatic cells may not be 100 percent complete even if the animal is born at full term. Griffin thinks developmental abnormality is going to be a common phenomenon in cloning.

"It may well be that there are different tissues or aspects of physiology that are incompletely developed in different animals," he said.

# data[].attributes.attachment_link.description
French scientists raised fresh fears today about the dangers of cloning humans, saying it may cause serious long-term health problems. Researchers at France's Institut National de la Recherche Agronomique said a cow they cloned with DNA from an adult somatic cell appeared healthy but died...

# data[].attributes.headline
Pro's and Con's                       LB

# data[].attributes.subject
Pro's and Con's                       LB

# data[].attributes.body
1. Reproductive cloning would allow people who have a child who has died to seek redress for their losses.
2. Animals who are endangered can be cloned to save their species.
........................................................
1. Reproductive cloning would diminish the idea of uniqueness. It would violate the widely held convictions concerning human individuality and freedom, and could lead to devaluation of clones in comparison with non-clones.
2.

# data[].attributes.attachment_link.description
Reproductive cloning can help parents with no eggs and sperm create genetically related children. Reproductive cloning can help lesbians to have children without the use of donor sperm. And it would...

# data[].attributes.body
By cloning animals we can learn more about diseases causing mutations in genes. Stem cells can help repair damaged or diseased organs and tissues, and scientists believe cloning is the best method to create stem cells that are specific to individuals. Cloning can also work to revive certain animals that have recently went extinct.

# data[].attributes.attachment_link.readable_text
Our experiences have told us that, with a little work, we humans can clone just about anything we want, from frogs to sheep-and probably even ourselves.

So we can clone things. But why would we want to? Below are some of the ways in which cloning might be useful.

Cloning for medical purposes has the potential to benefit large numbers of people. How might cloning be used in medicine?

Cloning animal models of disease

Much of what researchers learn about human disease comes from studying animal models such as mice. Often, animal models are genetically engineered to carry disease-causing mutations in their genes. Creating these transgenic animals is a time-intensive process that requires trial-and-error and several generations of breeding. Cloning could help reduce the time needed to make a transgenic animal model, and the result would be a population of genetically identical animals for study.

Cloning to make stem cells

Stem cells build, maintain, and repair the body throughout our lives. Because these are processes that stem cells do naturally, they can be manipulated to repair damaged or diseased organs and tissues. But stem cells transferred from one person to another (such as in a bone marrow transplant) are seen as foreign, and they usually trigger an immune response.

Some researchers are looking at cloning as a way to create stem cells that are genetically identical to an individual. These cells could then be used for medical purposes, possibly even for growing whole organs. And stem cells cloned from someone with a disease could be grown in culture and studied to help researchers understand the disease and develop treatments.

In 2013, scientists at Oregon Health and Science University were the first to use cloning techniques to successfully create human embryonicstem cells. The donor DNA came from an 8-month-old with a rare genetic disease.

Find out more about Stem Cells.

You might have seen the Jurassic Park movies. In the original feature film, based on the Michael Crichton novel, scientists use DNA preserved for tens of millions of years to clone dinosaurs. They run into trouble, however, when they realize that the cloned creatures were smarter and fiercer than expected. Could we really clone dinosaurs?

In theory? Yes. You would need:

A well-preserved source of DNA from the extinct dinosaur, and

A closely related species, currently living, that could serve as an egg donor and surrogate mother.

In reality? Probably not.

It's extremely unlikely that dinosaur DNA could survive undamaged for such a long time. However, scientists have been working to clone species that became extinct more recently, using DNA from well-preserved tissue samples. A number of projects are underway to clone extinct species, including the wooly mammoth.

In 2009, scientists had their first near-success resurrecting an extinct animal. Using goats as egg donors and surrogates, they made several clones of a wild mountain goat called the bucardo-but the longest-surviving clone died soon after birth. Even if the effort eventually succeeds, the only frozen tissue sample comes from a female, so it will only produce female clones. However, scientists speculate they may beable to remove one X chromossome and add a Y chromosome from a related goat species to make a male.

Cloning endangered species is much easier, mainly because the surviving animals can donate healthy, living cells. In fact, several wild species have been cloned already, including two relatives of cattle called the guar and the banteng, mouflon sheep, deer, bison, and coyotes. However, some experts are skeptical that cloning can help a species recover. One big challenge endangered species face is the loss of genetic diversity, and cloning does nothing to address this problem. When a species has high genetic diversity, there is a better chance that some individuals would have genetic variations that could help them survive an environmental challenge such as an infectious disease. Cloning also does not address the problems that put the species in danger in the first place, such as habitat destruction and hunting. But cloning may be one more tool that conservation scientists can add to their toolbox.

Learn more about Conservation Genetics.

Left: the alpine ibex, a close cousin of the Bucardo. Right: the last remaining Bucardo with the research team before her eventual death. She was blindfolded to shield her eyes from the photographer's flash. Image courtesy of Advanced Cell Technology.

Reproducing a Deceased Pet

If you really wanted to, and if you had enough money, you could clone your beloved family cat. At least one biotechnology company in the United States has offered cat cloning services for the privileged and bereaved. But don't assume that your cloned kitty will be exactly the same as the one you know and love. An individual is a product of more than its genes-the environment plays an important role in shaping personality and many other traits.

On December 22, 2001, a kitten named CC made history as the first cat-and the first domestic pet-ever to be cloned. CC and Rainbow, the donor of CC's genetic material, are pictured at the right.

But do you notice something odd about this picture? If CC is a clone of Rainbow-an exact genetic copy-then why are they different colors?

The answer lies in the X chromosome. In cats, a gene that helps determine coat color resides on this chromosome. Both CC and Rainbow, being females, have two X chromosomes. (Males have one X and one Y chromosome.) Since the two cats have the exact same X chromosomes, they have the same two coat color genes, one specifying black and the other specifying orange.

Very early in her development, each of Rainbow's cells "turned off" oneentire X chromosome, thereby turning off either the black or the orange color gene. This process, called X-inactivation, happens normally in females, in order to prevent them from having twice as much X-chromosome activity as males. It also happens randomly, meaning that different cells turn off different X chromosomes.

So like all female mammals, Rainbow developed as a mosaic. Each cell that underwent X-inactivation gave rise to a patch of cells that had oneor the other coat color gene inactivated. Some patches specified black,other patches specified orange, and still others specified white, due to more complex genetic events. This is how all calico cats, like Rainbow, get their markings.

CC looks different because she was made from a somatic cell from Rainbow in which the X-chromosome with the orange gene had been inactivated; only the black gene was active. What's interesting is that, as CC developed, her cells did not change the inactivation pattern. Therefore, unlike Rainbow, CC developed without any cells that specified orange coat color. The result is CC's black and white tiger-tabby coat.

Left: CC (or Carbon Copy). Right: Rainbow. Photo courtesy TAMU, College of Veterinary Medicine.

Rainbow and CC are living proof that a clone will not look exactly like the donor of its genetic material.

Programs are underway to clone agricultural animals, such as cattle and pigs, that are efficient producers of high-quality milk or meat.

A group of researchers at Utah State University led by Dr. Ken White, Dean of College of Agriculture & Applied Science, have been able to clone steer from slaughterhouse carcasses. Their aim isn't to produce animals for consumption-cloning is far more labor-intensive and expensive than conventional breeding methods. Instead, they want to use these animals as breeding stock.

The important thing to know about beef cattle is that the quality and yield of their meat can be assessed only after they are slaughtered. And male animals are routinely neutered when they're a few days old. That is, their testes are removed, so they are unable to make sperm. But cells from a high-quality carcass can be cloned, giving rise to an animal that is able, though conventional breeding methods, to pass its superior genes to its offspring.

Scientists have also cloned mules, a reproductively sterile hybrid of a male donkey and a female horse; dairy cows; and horses. One gelded racing horse, a male whose testes have been removed, has a clone that is available for breeding. Some of the cloned cows produce about twice as much milk as the average producer. And a cloned racing mule is ranked among the best in the world.

Farm animals such as cows, sheep, and goats are being genetically engineered to produce drugs or proteins that are useful in medicine. As an example, scientists could take cells from a cow that produces large amounts of milk and grow them in culture. Then they could insert a gene into the DNA of these cells that codes for a drug or a vaccine. If they take the nucleus from one of these cells and transfer it to a cow egg, it could develop into a cow that makes the drug in its milk. Since every cell in the cow would carry the drug gene, it could pass the gene to its offspring, creating a whole herd of drug-producing cows. Even better, we could avoid the issue of the genetic reshuffling that happensduring sexual reproduction and simply clone our drug-producing cow.

The prospect of cloning humans is highly controversial, and it raises a number of ethical, legal, and social challenges that need to be considered.

The vast majority of scientists and lawmakers view human reproductive cloning-cloning for the purpose of making a human baby-immoral. Supporters see it as a possible solution to infertility problems. Some even imagine making clones of geniuses, whose work could advance society. Far-fetched views describe farms filled with clones whose organs are harvested for transplantation-a truly horrific idea.

For now, risks and technical challenges-as well as laws that make it illegal-will probably keep human reproductive cloning from becoming a reality. Even though many species have been cloned successfully, theprocess is still technically difficult and inefficient. The success rate in cloning is quite low: most embryos fail to develop, and many pregnancies end in miscarriage.

Current efforts at human cloning are focused on creating embryonic stem cells for research and medicine, as described above. However, many feel that this type of therapeutic cloning comes dangerously close to human reproductive cloning. And once techniques become more streamlined and efficient, they fear that some may be tempted to take that next step.

From a technical and moral standpoint, before human cloning becomes routine, we need to have a good idea of the risks involved.

# data[].attributes.attachment_link.description
Our experiences have told us that, with a little work, we humans can clone just about anything we want, from frogs to sheep-and probably even ourselves. So we can clone things. But why would we want to? Below are some of the ways in which cloning might be useful.

# data[].attributes.body
- EH
A woman cloned herself (gene cloning) and gave birth to a healthy baby. Born outside of the U.S. However, mother will not provide genetic proof. In most cases the embryo is aborted by the body. Therefore, there are many skeptical scientists.

# data[].attributes.attachment_link.readable_text
The world's first cloned baby was born on 26 December, claims the Bahamas-based cloning company Clonaid. But there has been no independent confirmation of the claim.

The girl, named Eve by the cloning team, was said to have been born by Caesarean section at 1155 EST. The birth at an undisclosed location went "very well", said Brigitte Boisselier, president of Clonaid. The company was formed in 1997 by the Raelian cult, which believes people are clones of aliens.

"The baby is very healthy. She is doing fine," Roisselier told a press conference in Hollywood, Florida, on Friday. The seven-pound baby is a clone of a 31-year-old American woman, whose partner is infertile, she said.

Proving that the baby is a clone of another person would be possible by showing that their DNA is identical. Genetic tests on the baby and "mother" will now be carried out and the results will be available "in eight or nine days", Boisselier said.

Advertisement

She told reporters&colon; "You can still go back to your office and treat me as a fraud. You have one week to do that." Boisselier added that Michael Guillen, science editor at ABC News and a former Harvard University mathematician, will carry out the genetic tests.

Necessary expertise

Many scientists are sceptical of Boisselier's claim. Alan Trounson of Monash University in Melbourne, Australia, says he does not believe the group has the necessary expertise to clone a person. "And nearly everything they have said in the past has never been confirmed by scientific investigation," he told the Sydney Morning Herald.

Maverick fertility scientist Severino Antinori, who claimed earlier in December that the first cloned baby would be born in January 2003, is also critical. "An announcement of this type has no scientific corroboration and risks creating confusion," he said. "We keep up our scientific work without making announcements. I don't take part in this ... race."

Opponents of human cloning point to the high rate of miscarriages of cloned animal fetuses, and the high rate of defects in live births. Boisselier has claimed that the large number of female cult members willing to act as surrogate mothers increased their chances of success.

"Irresponsible and repugnant"

Attempting to clone humans is "irresponsible and repugnant and ignores the overwhelming scientific evidence from seven mammalian species cloned so far," Rudolph Jaenisch, a cloning expert at the Massachusetts Institute of Technology told New Scientist previously.

In May, US-based fertility scientist Panos Zavos told the US Congress that five groups of scientists were rushing to be the first to produce the first cloned human baby.

Reproductive cloning - creating a baby rather than a cloned early embryo - is illegal in many countries. But in November, talks on a global ban were suspended, following a series of deadlocked United Nations meetings.

# data[].attributes.attachment_link.description
The world's first cloned baby was born on 26 December, claims the Bahamas-based cloning company Clonaid. But there has been no independent confirmation of the claim. The girl, named Eve by the cloning team, was said to have been born by Caesarean section at 1155 EST.

# data[].attributes.body
*May cause serious long-term health problems
*Miscarriage
*Errors in it's DNA genetic reprogramming
*technology is unsafe
*stops the immune system from developing.
*different tissues can be developed in different animals

# data[].attributes.attachment_link.readable_text
Roxanne Maas

Based in Los Angeles, Roxanne Maas holds a master's degree in genetic counseling with more than 12 years of experience communicating complex genetics and pregnancy information. She has published several abstracts in scientific journals, presented posters at national genetics meetings, and published health-related articles on LIVESTRONG.com.

Cloning refers to various techniques of copying genetic information. Reproductive cloning, the most controversial type of cloning, creates copies of whole organisms. While the process of cloning results in two organisms that are genetically identical, the clone faces risks that the original organism does not. Although the technologies that enable cloning continue to improve, most clones as of 2010 do not survive or develop properly for a variety of reasons.

Video of the Day

Most cases of cloning to date -- September 2010 -- have proven unsuccessful. Scientists have attempted to clone a variety of animals, and in almost all cases, the embryo has failed to develop properly or survive for more than a short period of time. The Genetic Science Learning Center estimates that the success rate of cloning ranges from only 0.1 percent to 3 percent. A cloned embryo, for example, faces the same challenges as a natural pregnancy plus others that are particular to cloning.

In the process of cloning, a scientist removes the nucleus of the egg, which is the part that contains the genetic information, and replaces it with the nucleus of another cell. In some cases, the two cells involved are not incompatible and the cell cannot survive. In addition, like some transplant patients whose bodies reject the transplanted organ, an egg with a transplanted nucleus may reject the new nucleus by failing to grow and divide. Cloned embryos that survive the initial hours still may fail to implant into the surrogate's uterus. Finally, an established pregnancy can still, at any time and for a variety of reasons, cease growing and result in a miscarriage.

Cloned embryos that survive pregnancy can be born with a variety of birth defects and other health problems. According to the FDA, one phenomenon seen in cloning is that cloned animals tend to be larger than normal at birth, with unusually large organs. Enlarged organs often function improperly, causing problems with circulation, breathing and other bodily functions, sometimes leading to early death. Cloned animals often have malformations of various organs and body parts. In addition, their immune systems may fail to work properly, leading to later disease development.

Genetic material, or DNA, comes preprogrammed so that certain genes are "turned on," or expressed, at certain times while other genes are "turned off." Normal gene expression is integral to normal development of an organism; as cells start to differentiate into different types, such as skin cells, nerve cells and blood cells, genes need to turn on and off in a particular order. Cloned cells, however, may lack the programming necessary to tell genes when to turn on and off. The result may be disorganized cell growth or inappropriate cell functioning, both of which can lead an organism to die.

# data[].attributes.attachment_link.description
Cloning refers to various techniques of copying genetic information. Reproductive cloning, the most controversial type of cloning, creates copies of whole organisms. While the process of cloning results in two organisms that are genetically identical, the clone faces risks that the original organism does not. Although the technologies that enable...

# data[].attributes.body
-EH
1) One main concern for religious organizations is the tampering with human life. You were created the way you should be created.
2) Cloning can lead to an abortion. Certain embryos are aborted if found with a genetic error.

# data[].attributes.body
In 2008, scientists announced that they had cloned 5 human embryos. The embryos matured to the stage where they could have been implanted, however the scientists destroyed them in interest of performing molecular analysis on them.

# data[].attributes.attachment_link.readable_text
Why is cloning important?

Why is cloning controversial?

cloning, the process of generating a genetically identical copy of a cell or an organism. Cloning happens often in nature-for example, when a cell replicates itself asexually without any genetic alteration or recombination. Prokaryotic organisms (organisms lacking a cell nucleus) such as bacteria create genetically identical duplicates of themselves using binary fission or budding. In eukaryotic organisms (organisms possessing a cell nucleus) such as humans, all the cells that undergo mitosis, such as skin cells and cells lining the gastrointestinal tract, are clones; the only exceptions are gametes ( eggs and sperm), which undergo meiosis and genetic recombination.

In biomedical research, cloning is broadly defined to mean the duplication of any kind of biological material for scientific study, such as a piece of DNA or an individual cell. For example, segments of DNA are replicated exponentially by a process known as polymerase chain reaction, or PCR, a technique that is used widely in basic biological research. The type of cloning that is the focus of much ethical controversy involves the generation of cloned embryos, particularly those of humans, which are genetically identical to the organisms from which they are derived, and the subsequent use of these embryos for research, therapeutic, or reproductive purposes.

Early cloning experiments

Reproductive cloning was originally carried out by artificial "twinning," or embryo splitting, which was first performed on a salamander embryo in the early 1900s by German embryologist Hans Spemann. Later, Spemann, who was awarded the Nobel Prize for Physiology or Medicine (1935) for his research on embryonic development, theorized about another cloning procedure known as nuclear transfer. This procedure was performed in 1952 by American scientists Robert W. Briggs and Thomas J. King, who used DNA from embryonic cells of the frog Rana pipiens to generate cloned tadpoles. In 1958 British biologist John Bertrand Gurdon successfully carried out nuclear transfer using DNA from adult intestinal cells of African clawed frogs ( Xenopus laevis). Gurdon was awarded a share of the 2012 Nobel Prize in Physiology or Medicine for this breakthrough.

Advancements in the field of molecular biology led to the development of techniques that allowed scientists to manipulate cells and to detect chemical markers that signal changes within cells. With the advent of recombinant DNA technology in the 1970s, it became possible for scientists to create transgenic clones-clones with genomes containing pieces of DNA from other organisms. Beginning in the 1980s mammals such as sheep were cloned from early and partially differentiated embryonic cells. In 1996 British developmental biologist Ian Wilmut generated a cloned sheep, named Dolly, by means of nuclear transfer involving an enucleated embryo and a differentiated cell nucleus. This technique, which was later refined and became known as somatic cell nuclear transfer (SCNT), represented an extraordinary advance in the science of cloning, because it resulted in the creation of a genetically identical clone of an already grown sheep. It also indicated that it was possible for the DNA in differentiated somatic (body) cells to revert to an undifferentiated embryonic stage, thereby reestablishing pluripotency-the potential of an embryonic cell to grow into any one of the numerous different types of mature body cells that make up a complete organism. The realization that the DNA of somatic cells could be reprogrammed to a pluripotent state significantly impacted research into therapeutic cloning and the development of stem cell therapies.

Soon after the generation of Dolly, a number of other animals were cloned by SCNT, including pigs, goats, rats, mice, dogs, horses, and mules. Despite those successes, the birth of a viable SCNT primate clone would not come to fruition until 2018, and scientists used other cloning processes in the meantime. In 2001 a team of scientists cloned a rhesus monkey through a process called embryonic cell nuclear transfer, which is similar to SCNT except that it uses DNA from an undifferentiated embryo. In 2007 macaque monkey embryos were cloned by SCNT, but those clones lived only to the blastocyst stage of embryonic development. It was more than 10 years later, after improvements to SCNT had been made, that scientists announced the live birth of two clones of the crab-eating macaque ( Macaca fascicularis), the first primate clones using the SCNT process. (SCNT has been carried out with very limited success in humans, in part because of problems with human egg cells resulting from the mother's age and environmental factors.)

# data[].attributes.attachment_link.description
Cloning, the process of generating a genetically identical copy of a cell or an organism. Cloning happens often in nature, as when a cell replicates itself asexually without genetic alteration or recombination. Learn more about cloning experiments, cloning techniques, and the ethics of human reproductive cloning.

# data[].attributes.body
Cloning a human is an estimate of about $2 million. Cloning a cow costs about $20,000. House cats can be cloned privately for $32,000.

# data[].attributes.attachment_link.readable_text
The scientists who announced yesterday that they had cloned a human embryo--a first--want to eventually use cloning as a therapy for diseases like AIDS and Parkinson's. But one thing evident from their research: Such therapeutic cloning could be a very expensive treatment, more costly than even the priciest drugs.

These researchers, working at privately held Advanced Cell Technology (ACT) in Worcester, Mass., have no intention of creating cloned babies. Instead, they want to use somatic cell nuclear transfer, the same process used to clone Dolly the sheep in 1997, to create embryonic stem cells. The cloned cells would be genetically identical to the patient's own, so they could replace part of an ailing brain or heart without touching off a full-scale attack from the patient's immune system.

At least, that's the theory. But creating a cloned embryo requires human egg cells, and egg cells aren't cheap. In vitro fertilization clinics will generally pay an egg donor $3,000 to $5,000, and Advanced Cell Technology took 71 eggs from seven women.

Each of these women had to be treated with drugs, first to stop their ovary production, then to kickstart it into overdrive so that she could provide the scientists with about ten eggs each. Removing the eggs requires a serious medical procedure that can scar.

The process looks at least as inefficient as cloning in animals. Nineteen eggs underwent nuclear transfer. Their genetic material was removed and replaced with similar material from a donor. They then began to divide into embryos, but none grew past the six-cell stage. Stem cells are taken from embryos with more than 100 cells.

Researchers working with animals don't have to worry about getting enough eggs. Cow eggs, for instance, can be bought cheaply from slaughterhouses that would otherwise discard them. For a recent paper on cloning in Science, Peter Mombaerts Peter Mombaerts, a scientist at Rockefeller University in New York City who clones mice, ran through 4,000 mouse oocytes--he estimates that might be $2,000 worth of mice. Doing the same work in humans, he estimates, could cost $2 million.

Scientists will almost certainly use fewer eggs if therapeutic cloning is used on people. But even if it required a mere 100 eggs, taken from ten donors, the cost of simply paying the donors could easily reach $50,000. On top of that, there would be medical costs involved in procuring the egg. Mombaerts believes it could cost more than $1,000 per egg when all is said and done. That means costs to treat one patient could conceivably soar above $100,000.

That would make eggs the limiting factor in using nuclear transfer to treat human diseases. Such high costs are not unheard of in biotechnology--for instance, treating a patient for a year with a rare joint disorder called Gaucher's disease with Genzyme 's Cerezyme can cost $170,000.

ACT Chief Executive Michael West Michael West has in the past expressed a belief that if the cure works, it will be paid for. But West was once worried enough about the problem that ACT tried to create human stem cells using cow eggs. Geron , the stem-cell company he founded before moving to ACT, has often talked of nuclear transfer as a way of figuring out how to make stem cells. Geron's current CEO, Thomas Okarma Thomas Okarma, believes the first uses of embryonic stem cells as a therapy will have to make use of powerful drugs that suppress the immune system.

Another limiting factor on cloning: expertise. Mombaerts calls his former colleague Teru Wakayama Teru Wakayama, who is now at ACT, "the Tiger Woods of the micropipette." The inference is that, like golf, cloning mouse cells is a skill that involves exactly how the requisite tool is held and used--an art as much as a science. "That's one reason scientists think it will be a decade or two before this technology reaches the clinic."

Nonetheless, ACT's paper, published yesterday in the Journal of Reproductive Medicine, provides a guidebook to groups that want to clone human embryos to make babies. The steps at the beginning are the same. That is likely to spook lawmakers who already voted in the House of Representatives to make all human cloning, including the therapeutic kind, illegal. If the Senate passes a similar bill, President George W. Bush George W. Bush will surely sign it.

Whatever the lawmakers decide, though, this work will almost certainly continue--if not on U.S. soil, then elsewhere. "They've bitten the bullet now," Mombaerts says. "We can't go back."

More From Forbes

Geron, And Stem Cells, Keep On Going

Stem-Cell Numbers Game

House Votes To Ban All Cloning

An 800-Pound Gorilla In The Stem-Cell Debate

We Cloned You. Now, Here's The Bill

Forbes Full Coverage: Stem Cells And Cloning

Elsewhere On The Web

Advanced Cell Technology Press Release

The Journal of Regenerative Medicine

# data[].attributes.attachment_link.description
The scientists who announced yesterday that they had cloned a human embryo--a first--want to eventually use cloning as a therapy for diseases like AIDS and Parkinson's. But one thing evident from their research: Such therapeutic cloning could be a very expensive treatment, more costly than even the priciest drugs.

# data[].attributes.body
Therapeutic cloning does not clone a human but it instead involves taking a cell from  the body, removing the nucleus and transporting it into an empty egg. Embryo's contain stem cells that can grow into any cell in the body. Scientists believe this can treat many disorders and conditions because we would be able to regrow dead or damaged cells, and even grow organs.

# data[].attributes.attachment_link.description
Therapeutic cloning is still very new, although scientists have been able to develop the process in animals. Researchers believe that it could be used to treat a wide range of inherited disorders and conditions.

# data[].attributes.body
-EH
Gene Cloning is more commonly known as Somatic Cell Nuclear infusion. It works by extracting the DNA from the cells of the donor (usually a skin cell). The DNA is inserted into the recipient's egg cells. The recipient's egg cells have their nuclei removed, and are ready to copy the DNA of the donor.

# data[].attributes.attachment_link.readable_text
Cloning refers to the process of developing an embryo with the DNA from an adult animal.

Credit: Dreamstime

Cloning may invoke an image of an army of identical cows or sheep churned out factory-style, but in actuality, the process is much more laborious.

The term " cloning" generally applies to a process more technically known as somatic cell nuclear transfer. What that means is that the DNA from the cell of an adult animal (take cows, for example), called the "donor," is extracted from the cell (usually a skin cell taken in a biopsy) and inserted into an egg cell from another cow. The egg cell has had its nucleus removed so that it will read and duplicate the DNA of the donor cell.

The newly created embryo is then zapped with electricity so that it starts multiplying, until it becomes a blastocyst (a small clump of cells that forms after an egg is fertilized), which is then implanted into a surrogate mother. The resulting newborn will be an identical genetic replica to the donor cow.

Cows have been cloned more than other animals because obtaining eggs from the cow is slightly easier than for swine, said geneticist Bill Muir of Purdue University, an author of a 2002 National Academy of Sciences report on the scientific concerns of animal biotechnology.

This process differs from other methods of artificial breeding, such as in vitro fertilization, in that it uses adult cells, instead of embryos.

Follow Life's Little Mysteries on Twitter @llmysteries. We're also on Facebook & Google+.

# data[].attributes.attachment_link.description
Cloning may invoke an image of an army of identical cows or sheep churned out factory-style, but in actuality, the process is much more laborious. The term " cloning" generally applies to a process more technically known as somatic cell nuclear transfer.

# data[].attributes.body
The production of a genetic duplicate of an existing organism

# data[].attributes.headline
                                                         Types Of Cloning

# data[].attributes.subject
                                                         Types Of Cloning