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The Cloning Debates and Progress in Biotechnology

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Paul L Wolf, George Liggins, Dan Mercola, The Cloning Debates and Progress in Biotechnology, Clinical Chemistry , Volume 43, Issue 11, 1 November 1997, Pages 2019–2020, https://doi.org/10.1093/clinchem/43.11.2019

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The perception by humans of what is doable is itself a great determiner of future events. Thus, the successful sheep cloning experiment leading to “Dolly” by Ian Wilmut and associates at Roslin Institute, Midlothian, UK, compels us to look in the mirror and consider the issue of human cloning. Should it occur, and if not, how should that opposing mandate be managed? If human cloning should have an acceptable role, what is that role and how should it be monitored and supervised?

In the February 27, 1997, issue of Nature , Ian Wilmut et al. reported that they cloned a sheep (which they named “Dolly”) by transferring the nuclear DNA from an adult sheep udder cell into an egg whose DNA had been removed ( 1 ). Their cloning experiments have led to widespread debate on the potential application of this remarkable technique to the cloning of humans. Following the Scottish researchers’ startling report, President Clinton declared his opposition to using this technique to clone humans. He moved swiftly to order that federal funds not be used for such an experiment and asked an independent panel of experts, the National Bioethics Advisory Commission (NBAC), chaired by Princeton University President Harold Shapiro, to report to the White House with recommendations for a national policy on human cloning. According to recommendations by the NBAC, human cloning is likely to become a crime in the US in the near future. The Commission’s main recommendation is to enact federal legislation to prohibit any attempts, whether in a research or a clinical setting, to create a human through somatic cell nuclear transfer cloning.

The concept of genetic manipulation is not new and has been a general practice for more than a century, through practices ranging from selective cross-pollination in plants to artificial insemination in domestic farm animals.

Wilmut and his colleagues made 277 attempts before they succeeded with Dolly. Previously, investigators had reported successful cloning in frogs, mice, and cattle ( 2 )( 3 )( 4 )( 5 ), and 1 week after Wilmut’s report, Don Wolf and colleagues at the Oregon Regional Primate Research Center reported their cloning of two rhesus monkeys by utilizing embryonic cells. The achievement of Wilmut’s team shocked nucleic acid experts, who thought it would be an impossible feat. They believed that the DNA of adult cells could not perform similarly to the DNA formed when a spermatozoa’s genes mingle with those of an ovum.

On July 25, 1997, the Roslin team also reported the production of lambs that contained human genes ( 6 ). Utilizing techniques similar to those they had used in Dolly, they inserted a human gene into the nuclei of sheep cells. These cells were next inserted into the ova of sheep from which the DNA had been removed. The resulting lambs contained the human gene in every cell. In this new procedure the DNA had been inserted into skin fibroblast cells, which are specialized cells, unlike previous procedures in which DNA was introduced into a fertilized ovum. The new lamb has been named “Polly” because she is a Poll Dorset sheep. The goal of this new genetically engineered lamb is for these lambs to produce human proteins necessary for the treatment of human genetic diseases, such as factor VIII for hemophiliacs, cystic fibrosis transmembrane conductance regulator (CFTR) substance for patients with cystic fibrosis, tissue plasminogen activator to induce lysis of acute coronary and cerebral artery thrombi, and human growth factor.

Charles Darwin was frightened when he concluded that humans were not specifically separated from all other animals. Not until 20 years after his discovery did he have the courage to publish his findings, which changed the way humans view life on earth. Wilmut’s amazing investigations have also created worldwide fear, misunderstanding, and ethical shock waves. Politicians and a few scientists are proposing legislation to outlaw human cloning ( 7 ). Although the accomplishment of cloning clearly could provide many benefits to medicine and to conservation of endangered species of animals, politicians and a few scientists fear that the cloning procedure will be abused.

The advantages of cloning are numerous. The ability to clone dairy cattle may have a larger impact on the dairy industry than artificial insemination. Cloning might be utilized to produce multiple copies of animals that are especially good at producing meat, milk, or wool. The average cow makes 13 000 pounds (5800 kg) of milk a year. Cloning of cows that are superproducers of milk might result in cows producing 40 000 pounds (18 000 kg) of milk a year.

Wilmut’s recent success in cloning “Polly” represents his main interest in cloning ( 8 ). He believes in cloning animals able to produce proteins that are or may prove to be useful in medicine. Cloned female animals could produce large amounts of various important proteins in their milk, resulting in female animals that serve as living drug factories. Investigators might be able to clone animals affected with human diseases, e.g., cystic fibrosis, and investigate new therapies for the human diseases expressed by these animals.

Another possibility of cloning could be to change the proteins on the cell surface of heart, liver, kidney, or lung, i.e., to produce organs resembling human organs and enhancing the supply of organs for human transplantation. The altered donor organs, e.g., from pigs, would be less subject to rejection by the human recipient. The application of cloning in the propagation of endangered species and conservation of gene pools has been proposed as another important use of the cloning technique ( 9 )( 10 ).

The opponents of cloning have especially focused on banning the cloning of humans ( 11 ). The UK, Australia, Spain, Germany, and Denmark have implemented laws barring human cloning. Opponents of human cloning have cited potential ethical and legal implications. They emphasize that individuals are more than a sum of their genes. A clone of an individual might have a different environment and thus might be a different person psychologically and have a different “soul.” Cloning of a human is replication and not procreation.

Morally questionable uses of genetic material transfer and cloning obviously exist. For example, infertility experts might be especially interested in the cloning technique to produce identical twins, triplets, or quadruplets. Parents of a child who has a terminal illness might wish to have a clone of the child to replace the dying child. The old stigma, eugenics, also raises its ugly head if infertile couples wish to use the nuclear transfer techniques to ensure that their “hard-earned” offspring will possess excellent genes. Moral perspectives will differ tremendously in these cases. Judgments about the appropriateness of such uses are outside the realm of science.

Opponents of animal cloning are concerned that cloning will negate genetic diversity of livestock. This also applies to human cloning, which could negate genetic diversity of humans. Cloning creates, by definition, a second class of human, a human with a determined genotype called into existence, however benevolently, at the behest of another. The insulation of selection-of-mate is lost, and the second class is created. Few contrasts could be so clear. Selection-of-mate is so imprecise that, at present, would-be parents have to accept a complete new genome for the sake of including or excluding one or a few traits; cloning, in contrast, is the precise determination of all genes. If we acknowledge that the creation of a second class of humans is unethical, then we preempt any argument that some motivations for human cloning may be acceptable.

The opponents of cloning also fear that biotechnically cloned foods might increase the risk of humans acquiring some malignancies or infections such as “mad cow disease,” a prion spongiform dementia encephalopathy (human Jakob–Creutzfeldt disease).

The technological advances associated with manipulation of genetic materials now permit us to envision replacement of defective genes with “good” genes. Although current progress is not sufficient to make this practical today for human diseases, any efforts to stop such research as a result of cloning hysteria would preclude the development of true cures for many hereditary human diseases. Unreasonable restrictions on the use of human tissues in gene transfer research will have the inevitable consequences of delaying, if not preventing, the development of strategies to combat defective genes.

Wise legislation will enable humankind to realize the benefits of gene transfer technologies without risking the horrors that could arise from misuse of these technologies. Our hope is that such wise legislation is what will be enacted. In our view, the controversy surrounding human cloning must not lead to prohibitions that would prevent advances similar to those described here.

Wilmut I, Schnieke AE, McWhire J, Kind AJ, Campbell KHS. Viable offspring derived from fetal and adult mammalian cells. Nature 1997 ; 385 : 810 -813.

Pennisi E, Williams N. Will Dolly send in the clones?. Science 1997 ; 275 : 1415 -1416.

Gurdon JB, Laskey RA, Reeves OR. The developmental capacity of nuclei transplanted from keratinized skin cells of adult frogs. J Embryol Exp Morphol 1975 ; 34 : 93 -112.

Prather RS. Nuclei transplantation in the bovine embryo. Assessment of donor nuclei and recipient oocyte. Biol Reprod 1987 ; 37 : 859 -866.

Kwon OY, Kono T. Production of identical sextuplet mice by transferring metaphase nuclei from 4-cell embryos. J Reprod Fert Abst Ser 1996 ; 17 : 30 .

Kolata G. Lab yields lamb with human gene. NY Times 1997;166:July 25;A12..

Specter M, Kolta G. After decades of missteps, how cloning succeeded. NY Times 1997;166:March 3;B6–8..

Ibrahim YM. Ian Wilmut. NY Times 1997;166:February 24;B8..

Ryder OA, Benirschke K. The potential use of “cloning” in the conservation effort. Zoo Biol 1997 ; 16 : 295 -300.

Cohen J. Can cloning help save beleaguered species?. Science 1997 ; 276 : 1329 -1330.

Williams N. Cloning sparks calls for new laws. Science 1997;275:141-5..

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Cloning is a method that is used to produce genetically identical copies of pieces of DNA, cells or organisms. Cloning methods include: molecular cloning, which makes copies of pieces of DNA; cellular cloning, which makes copies of a cell; and whole organism cloning. All cloning methods involve DNA and cell manipulation.

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Scientific and Ethical Implications of Human and Animal Cloning

Sidra Shafique

Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada

Contributor Roles: Sidra Shafique is the sole author. The author read and approved the final manuscript.

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Cloning is an old paradigm with new ethical issues that society is confronting today and will do so tomorrow. In this publication, cloning has been reviewed from the perspective of its broad implications on research, agriculture, pets, sports animals and humans. Reflection of legal status shows a picture of cloning applications that is not only inevitable but expected to change human species forever. Weighing advantages vs disadvantages of either the reproductive cloning or therapeutic one sums up into unnatural acts, changing the diversity of society and risks of exploitation. Modern biotechnology can only clone the genomes, not the individuals. Cultural inheritance comes from the development and adaptation of individuality generation after generation. The biological inheritance may be copied but the cultural inheritance cannot be duplicated. Human cloning infringes upon the principles of individual freedom, identity, and autonomy. Here, the current impacts of cloning are elaborated in comparison to the past and predicting what could happen tomorrow. In any scenario, public discussion and involvement of society must be preceded by making or amending laws and regulations. Risk assessment, enforcing justice and altered explanation of ‘words’ and ‘definitions might be the next stance for bioethicists and lawyers shortly. However, scientists and the regulatory authorities are of the view that the way IVF and animal cloning have been gradually accepted, the fourteen days blastocyst cultivation has been justified, one day the human cloning will also get the approval of a common man. As science will advance, the ethicist and theologists would come up with a favorable argument too, maybe three decades from now. In the present publication, the issue of cloning in general with a focus on human cloning, in particular, is discussed understandably by everyone interested in cloning and its impacts on society.

Human Cloning, Animal Cloning, Ethical Issues, Reproductive Cloning, Legislation, Cultural Inheritance

Sidra Shafique. (2020). Scientific and Ethical Implications of Human and Animal Cloning. International Journal of Science, Technology and Society , 8 (1), 9-17. https://doi.org/10.11648/j.ijsts.20200801.12

Sidra Shafique. Scientific and Ethical Implications of Human and Animal Cloning. Int. J. Sci. Technol. Soc. 2020 , 8 (1), 9-17. doi: 10.11648/j.ijsts.20200801.12

Sidra Shafique. Scientific and Ethical Implications of Human and Animal Cloning. Int J Sci Technol Soc . 2020;8(1):9-17. doi: 10.11648/j.ijsts.20200801.12

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Animal Cloning ( See Animal Ethics; Animal Research; Cloning)

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Cloning in the animal world is achieved naturally in several ways. Asexual reproduction is when an organism creates a copy of itself without any contribution of genetic material from another individual. It is the most elementary form of (plant and) animal cloning and happens in nature through fragmentation (a new organism grows from a fragment of the progenitor), gemmulation (aggregates of cells mostly archaeocytes become isolated), and parthenogenesis (an unfertilized egg develops into a new individual). Although not involving genetic material from a second source, parthenogenesis can be considered sexual reproduction because it involves gametes.

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ten Have, H., Patrão Neves, M. (2021). Animal Cloning ( See Animal Ethics; Animal Research; Cloning). In: Dictionary of Global Bioethics. Springer, Cham. https://doi.org/10.1007/978-3-030-54161-3_53

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Reproduction by cloning has been achieved by transfer into enucleated oocytes of nuclei from embryonic cells and more recently from cells of adult animals. The efficiency at which embryos produced by such nuclear transfers will develop into healthy newborns is very low but has allowed to produce some cloned bovines, bovines and mice. Since the first report of sheep cloning from an adult cell in 1997, the potential applications of reproductive cloning in human medicine have been envisaged amidst a flurry of moral debates. Although the technology is still far from being ready for any human use, it has been condemned from the outset. It has also led to irrational fantasies and fears mainly based on the misconception that genetic identity means identical twin personalities. Scientific research is ongoing on refining the cloning technology for applications in the production of genetically homogeneous farm animals with useful nutritional or therapeutic genetic traits. A new area of research is non-reproductive therapeutic cloning for the purpose of producing autologous embryonic cells and tissues for transplantation.

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Ethical Issues in Animal Cloning

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The issue of human reproductive cloning has recently received a great deal attention in public discourse. Bioethicists, policy makers, and the media have been quick to identify the key ethical issues involved in human reproductive cloning and to argue, almost unanimously, for an international ban on such attempts. Meanwhile, scientists have proceeded with extensive research agendas in the cloning of animals. Despite this research, there has been little public discussion of the ethical issues raised by animal cloning projects. Polling data show that the public is decidedly against the cloning of animals. To understand the public’s reaction and fill the void of reasoned debate about the issue,we need to review the possible objections to animal cloning and assess the merits of the anti–animal cloning stance. Some objections to animal cloning (e.g., the impact of cloning on the population of unwanted animals) can be easily addressed, while others (e.g., the health of cloned animals) require more serious attention by the public and policy makers.

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Animal cloning

So Dolly was not the first clone, and she looked like any other sheep, so why did she cause so much excitement and concern? Because she was the first mammal to be cloned from an adult cell, rather than an embryo. This was a major scientific achievement, but also raised ethical concerns. Since 1996, when Dolly was born, other sheep have been cloned from adult cells, as have mice, rabbits, horses and donkeys, pigs, goats and cattle. In 2004 a mouse was cloned using a nucleus from an olfactory neuron, showing that the donor nucleus can come from a tissue of the body that does not normally divide.

How was Dolly produced?

Producing an animal clone from an adult cell is obviously much more complex and difficult than growing a plant from a cutting. So when scientists working at the Roslin Institute in Scotland produced Dolly, the only lamb born from 277 attempts, it was a major news story around the world. To produce Dolly, the scientists used the nucleus of an udder cell from a six-year-old Finn Dorset white sheep. The nucleus contains nearly all the cell's genes. They had to find a way to 'reprogram' the udder cells - to keep them alive but stop them growing – which they achieved by altering the growth medium (the ‘soup’ in which the cells were kept alive). Then they injected the cell into an unfertilised egg cell which had had its nucleus removed, and made the cells fuse by using electrical pulses. The unfertilised egg cell came from a Scottish Blackface ewe. When the scientists had managed to fuse the nucleus from the adult white sheep cell with the egg cell from the black-faced sheep, they needed to make sure that the resulting cell would develop into an embryo. They cultured it for six or seven days to see if it divided and  developed normally, before implanting it into a surrogate mother, another Scottish Blackface ewe. Dolly had a white face. From 277 cell fusions, 29 early embryos developed and were implanted into 13 surrogate mothers. But only one pregnancy went to full term, and the 6.6kg Finn Dorset lamb 6LLS (alias Dolly) was born after 148 days.

Why are scientists interested in cloning?

The main reason that the scientists at Roslin wanted to be able to clone sheep and other large animals was connected with their research aimed at producing medicines in the milk of such animals. Researchers have managed to transfer human genes that produce useful proteins into sheep and cows, so that they can produce, for instance, the blood clotting agent factor IX to treat haemophilia or alpha-1-antitrypsin to treat cystic fibrosis and other lung conditions. Cloned animals could also be developed that would produce human antibodies against infectious diseases and even cancers. ‘Foreign’ genes have been transplanted into zebra fish, which are widely used in laboratories, and embryos cloned from these fish express the foreign protein. If this technique can be applied to mammalian cells and the cells cultured to produce cloned animals, these could then breed conventionally to form flocks of genetically engineered animals all producing medicines in their milk. There are other medical and scientific reasons for the interest in cloning. It is already being used alongside genetic techniques in the  development of animal organs for transplant into humans (xenotransplantation). Combining such genetic techniques with cloning of pigs (achieved for the first time in March 2000) would lead to a reliable supply of suitable donor organs. The use of pig organs has been hampered by the presence of a sugar, alpha gal, on pig cells, but in 2002 scientists succeeded in knocking out the gene that makes it, and these ‘knockout’ pigs could be bred naturally. However, there are still worries about virus transmission. The study of animal clones and cloned cells could lead to greater understanding of the development of the embryo and of ageing and  age-related diseases. Cloned mice become obese, with related symptoms such as raised plasma insulin and leptin levels, though their offspring do not and are normal. Cloning could be used to create better animal models of diseases, which could in turn lead to further progress in understanding and treating those diseases. It could even enhance biodiversity by ensuring the continuation of rare breeds and endangered species.

What happened to Dolly?

Dolly, probably the most famous sheep in the world, lived a pampered existence at the Roslin Institute. She mated and produced normal offspring in the normal way, showing that such cloned animals can reproduce. Born on 5 July 1996, she was euthanased on 14 February 2003, aged six and a half. Sheep can live to age 11 or 12, but Dolly suffered from arthritis in a hind leg joint and from sheep pulmonary adenomatosis, a virus-induced lung tumour to which sheep raised indoors are prone. On 2 February 2003, Australia's first cloned sheep died unexpectedly at the age of two years and 10 months. The cause of death was unknown and the carcass was quickly cremated as it was decomposing. Dolly’s chromosomes were are a little shorter than those of other sheep, but in most other ways she was the same as any other sheep of her chronological age. However, her early ageing may reflect that she was raised from the nucleus of a 6-year old sheep. Study of her cells also revealed that the very small amount of DNA outside the nucleus, in the mitochondria of the cells, is all inherited from the donor egg cell, not from the donor nucleus like the rest of her DNA. So she is not a completely identical copy. This finding could be important for sex-linked diseases such as haemophilia, and certain neuromuscular, brain and kidney conditions that are passed on through the mother's side of the family only.

Improving the technology

Scientists are working on ways to improve the technology. For example, when two genetically identical cloned mice embryos are combined, the aggregate embryo is more likely to survive to birth. Improvements in the culture medium may also help.

Ethical concerns and regulation

Most of the ethical concerns about cloning relate to the possibility that it might be used to clone humans. There would be enormous technical difficulties. As the technology stands at present, it would have to involve women willing to donate perhaps hundreds of eggs, surrogate pregnancies with high rates of miscarriage and stillbirth, and the possibility of premature ageing and high cancer rates for any children so produced. However, in 2004 South Korean scientists announced that they had cloned 30 human embryos, grown them in the laboratory until they were a hollow ball of cells, and produced a line of stem cells from them. Further ethical discussion was raised in 2008 when scientists succeeded in cloning mice from tissue that had been frozen for 16 years. In the USA, President Clinton asked the National Bioethics Commission and Congress to examine the issues, and in the UK the House of Commons Science and Technology Committee, the Human Embryology and Fertilisation Authority and the Human Genetics Advisory Commission all consulted widely and advised that human cloning should be banned. The Council of Europe has banned human cloning: in fact most countries have banned the use of cloning to produce human babies (human reproductive cloning). However, there is one important medical aspect of cloning technology that could be applied to humans, which people may find less objectionable. This is therapeutic cloning (or cell nucleus replacement) for tissue engineering, in which tissues, rather than a baby, are created. In therapeutic cloning, single cells would be taken from a person and 'reprogrammed' to create stem cells, which have the potential to  develop into any type of cell in the body. When needed, the stem cells could be thawed and then induced to grow into particular types of cell such as heart, liver or brain cells that could be used in medical treatment. Reprogramming cells is likely to prove technically difficult. Therapeutic cloning research is already being conducted in animals, and stem cells have been grown by this method and transplanted back into the original donor animal. In humans, this technique would revolutionise cell and tissue transplantation as a method of treating diseases. However, it is a very new science and has raised ethical concerns. In the UK a group headed by the Chief Medical Officer, Professor Liam Donaldson, has recommended that research on early human embryos should be allowed. The Human Fertilisation and Embryology Act was amended in 2001 to allow the use of embryos for stem cell research and consequently the HFEA has the responsibility for regulating all embryonic stem cell research in the UK. There is a potential supply of early embryos as patients undergoing in-vitro fertilisation usually produce a surplus of fertilised eggs. As far as animal cloning is concerned, all cloning for research or medical purposes in the UK must be approved by the Home Office under the strict controls of the Animals (Scientific Procedures) Act 1986 . This safeguards animal welfare while allowing important scientific and medical research to go ahead.

Further information

The Roslin Institute has lots of information about the research that led to Dolly, and the scientific studies of Dolly, as well as links to many other sites that provide useful information on the scientific and ethical aspects of this research. The report of the Chief Medical Officer's Expert Advisory Group on Therapeutic Cloning: Stem cell research: medical progress with responsibility is available from the UK Department of Health , PO Box 777, London SE1 6XH. Further information on therapeutic cloning and stem cell research is available from the Medical Research Council . Interesting illustrated features on cloning have been published by Time , New Scientist . BBC News Online has a Q&A What is Cloning?   IMAGE © THE ROSLIN INSTITUTE

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Cloning Fact Sheet

The term cloning describes a number of different processes that can be used to produce genetically identical copies of a biological entity. The copied material, which has the same genetic makeup as the original, is referred to as a clone. Researchers have cloned a wide range of biological materials, including genes, cells, tissues and even entire organisms, such as a sheep.

Do clones ever occur naturally?

Yes. In nature, some plants and single-celled organisms, such as bacteria , produce genetically identical offspring through a process called asexual reproduction. In asexual reproduction, a new individual is generated from a copy of a single cell from the parent organism.

Natural clones, also known as identical twins, occur in humans and other mammals. These twins are produced when a fertilized egg splits, creating two or more embryos that carry almost identical DNA . Identical twins have nearly the same genetic makeup as each other, but they are genetically different from either parent.

What are the types of artificial cloning?

There are three different types of artificial cloning: gene cloning, reproductive cloning and therapeutic cloning.

Gene cloning produces copies of genes or segments of DNA. Reproductive cloning produces copies of whole animals. Therapeutic cloning produces embryonic stem cells for experiments aimed at creating tissues to replace injured or diseased tissues.

Gene cloning, also known as DNA cloning, is a very different process from reproductive and therapeutic cloning. Reproductive and therapeutic cloning share many of the same techniques, but are done for different purposes.

What sort of cloning research is going on at NHGRI?

Gene cloning is the most common type of cloning done by researchers at NHGRI. NHGRI researchers have not cloned any mammals and NHGRI does not clone humans.

How are genes cloned?

Researchers routinely use cloning techniques to make copies of genes that they wish to study. The procedure consists of inserting a gene from one organism, often referred to as "foreign DNA," into the genetic material of a carrier called a vector. Examples of vectors include bacteria, yeast cells, viruses or plasmids, which are small DNA circles carried by bacteria. After the gene is inserted, the vector is placed in laboratory conditions that prompt it to multiply, resulting in the gene being copied many times over.

How are animals cloned?

In reproductive cloning, researchers remove a mature somatic cell , such as a skin cell, from an animal that they wish to copy. They then transfer the DNA of the donor animal's somatic cell into an egg cell, or oocyte, that has had its own DNA-containing nucleus removed.

Researchers can add the DNA from the somatic cell to the empty egg in two different ways. In the first method, they remove the DNA-containing nucleus of the somatic cell with a needle and inject it into the empty egg. In the second approach, they use an electrical current to fuse the entire somatic cell with the empty egg.

In both processes, the egg is allowed to develop into an early-stage embryo in the test-tube and then is implanted into the womb of an adult female animal.

Ultimately, the adult female gives birth to an animal that has the same genetic make up as the animal that donated the somatic cell. This young animal is referred to as a clone. Reproductive cloning may require the use of a surrogate mother to allow development of the cloned embryo, as was the case for the most famous cloned organism, Dolly the sheep.

What animals have been cloned?

Over the last 50 years, scientists have conducted cloning experiments in a wide range of animals using a variety of techniques. In 1979, researchers produced the first genetically identical mice by splitting mouse embryos in the test tube and then implanting the resulting embryos into the wombs of adult female mice. Shortly after that, researchers produced the first genetically identical cows, sheep and chickens by transferring the nucleus of a cell taken from an early embryo into an egg that had been emptied of its nucleus.

It was not until 1996, however, that researchers succeeded in cloning the first mammal from a mature (somatic) cell taken from an adult animal. After 276 attempts, Scottish researchers finally produced Dolly, the lamb from the udder cell of a 6-year-old sheep. Two years later, researchers in Japan cloned eight calves from a single cow, but only four survived.

Besides cattle and sheep, other mammals that have been cloned from somatic cells include: cat, deer, dog, horse, mule, ox, rabbit and rat. In addition, a rhesus monkey has been cloned by embryo splitting.

Have humans been cloned?

Despite several highly publicized claims, human cloning still appears to be fiction. There currently is no solid scientific evidence that anyone has cloned human embryos.

In 1998, scientists in South Korea claimed to have successfully cloned a human embryo, but said the experiment was interrupted very early when the clone was just a group of four cells. In 2002, Clonaid, part of a religious group that believes humans were created by extraterrestrials, held a news conference to announce the birth of what it claimed to be the first cloned human, a girl named Eve. However, despite repeated requests by the research community and the news media, Clonaid never provided any evidence to confirm the existence of this clone or the other 12 human clones it purportedly created.

In 2004, a group led by Woo-Suk Hwang of Seoul National University in South Korea published a paper in the journal Science in which it claimed to have created a cloned human embryo in a test tube. However, an independent scientific committee later found no proof to support the claim and, in January 2006, Science announced that Hwang's paper had been retracted.

From a technical perspective, cloning humans and other primates is more difficult than in other mammals. One reason is that two proteins essential to cell division, known as spindle proteins, are located very close to the chromosomes in primate eggs. Consequently, removal of the egg's nucleus to make room for the donor nucleus also removes the spindle proteins, interfering with cell division. In other mammals, such as cats, rabbits and mice, the two spindle proteins are spread throughout the egg. So, removal of the egg's nucleus does not result in loss of spindle proteins. In addition, some dyes and the ultraviolet light used to remove the egg's nucleus can damage the primate cell and prevent it from growing.

Do cloned animals always look identical?

No. Clones do not always look identical. Although clones share the same genetic material, the environment also plays a big role in how an organism turns out.

For example, the first cat to be cloned, named Cc, is a female calico cat that looks very different from her mother. The explanation for the difference is that the color and pattern of the coats of cats cannot be attributed exclusively to genes. A biological phenomenon involving inactivation of the X chromosome (See sex chromosome ) in every cell of the female cat (which has two X chromosomes) determines which coat color genes are switched off and which are switched on. The distribution of X inactivation, which seems to occur randomly, determines the appearance of the cat's coat.

What are the potential applications of cloned animals?

Reproductive cloning may enable researchers to make copies of animals with the potential benefits for the fields of medicine and agriculture.

For instance, the same Scottish researchers who cloned Dolly have cloned other sheep that have been genetically modified to produce milk that contains a human protein essential for blood clotting. The hope is that someday this protein can be purified from the milk and given to humans whose blood does not clot properly. Another possible use of cloned animals is for testing new drugs and treatment strategies. The great advantage of using cloned animals for drug testing is that they are all genetically identical, which means their responses to the drugs should be uniform rather than variable as seen in animals with different genetic make-ups.

After consulting with many independent scientists and experts in cloning, the U.S. Food and Drug Administration (FDA) decided in January 2008 that meat and milk from cloned animals, such as cattle, pigs and goats, are as safe as those from non-cloned animals. The FDA action means that researchers are now free to using cloning methods to make copies of animals with desirable agricultural traits, such as high milk production or lean meat. However, because cloning is still very expensive, it will likely take many years until food products from cloned animals actually appear in supermarkets.

Another application is to create clones to build populations of endangered, or possibly even extinct, species of animals. In 2001, researchers produced the first clone of an endangered species: a type of Asian ox known as a guar. Sadly, the baby guar, which had developed inside a surrogate cow mother, died just a few days after its birth. In 2003, another endangered type of ox, called the Banteg, was successfully cloned. Soon after, three African wildcats were cloned using frozen embryos as a source of DNA. Although some experts think cloning can save many species that would otherwise disappear, others argue that cloning produces a population of genetically identical individuals that lack the genetic variability necessary for species survival.

Some people also have expressed interest in having their deceased pets cloned in the hope of getting a similar animal to replace the dead one. But as shown by Cc the cloned cat, a clone may not turn out exactly like the original pet whose DNA was used to make the clone.

What are the potential drawbacks of cloning animals?

Reproductive cloning is a very inefficient technique and most cloned animal embryos cannot develop into healthy individuals. For instance, Dolly was the only clone to be born live out of a total of 277 cloned embryos. This very low efficiency, combined with safety concerns, presents a serious obstacle to the application of reproductive cloning.

Researchers have observed some adverse health effects in sheep and other mammals that have been cloned. These include an increase in birth size and a variety of defects in vital organs, such as the liver, brain and heart. Other consequences include premature aging and problems with the immune system. Another potential problem centers on the relative age of the cloned cell's chromosomes. As cells go through their normal rounds of division, the tips of the chromosomes, called telomeres, shrink. Over time, the telomeres become so short that the cell can no longer divide and, consequently, the cell dies. This is part of the natural aging process that seems to happen in all cell types. As a consequence, clones created from a cell taken from an adult might have chromosomes that are already shorter than normal, which may condemn the clones' cells to a shorter life span. Indeed, Dolly, who was cloned from the cell of a 6-year-old sheep, had chromosomes that were shorter than those of other sheep her age. Dolly died when she was six years old, about half the average sheep's 12-year lifespan.

What is therapeutic cloning?

Therapeutic cloning involves creating a cloned embryo for the sole purpose of producing embryonic stem cells with the same DNA as the donor cell. These stem cells can be used in experiments aimed at understanding disease and developing new treatments for disease. To date, there is no evidence that human embryos have been produced for therapeutic cloning.

The richest source of embryonic stem cells is tissue formed during the first five days after the egg has started to divide. At this stage of development, called the blastocyst, the embryo consists of a cluster of about 100 cells that can become any cell type. Stem cells are harvested from cloned embryos at this stage of development, resulting in destruction of the embryo while it is still in the test tube.

What are the potential applications of therapeutic cloning?

Researchers hope to use embryonic stem cells, which have the unique ability to generate virtually all types of cells in an organism, to grow healthy tissues in the laboratory that can be used replace injured or diseased tissues. In addition, it may be possible to learn more about the molecular causes of disease by studying embryonic stem cell lines from cloned embryos derived from the cells of animals or humans with different diseases. Finally, differentiated tissues derived from ES cells are excellent tools to test new therapeutic drugs.

What are the potential drawbacks of therapeutic cloning?

Many researchers think it is worthwhile to explore the use of embryonic stem cells as a path for treating human diseases. However, some experts are concerned about the striking similarities between stem cells and cancer cells. Both cell types have the ability to proliferate indefinitely and some studies show that after 60 cycles of cell division, stem cells can accumulate mutations that could lead to cancer. Therefore, the relationship between stem cells and cancer cells needs to be more clearly understood if stem cells are to be used to treat human disease.

What are some of the ethical issues related to cloning?

Gene cloning is a carefully regulated technique that is largely accepted today and used routinely in many labs worldwide. However, both reproductive and therapeutic cloning raise important ethical issues, especially as related to the potential use of these techniques in humans.

Reproductive cloning would present the potential of creating a human that is genetically identical to another person who has previously existed or who still exists. This may conflict with long-standing religious and societal values about human dignity, possibly infringing upon principles of individual freedom, identity and autonomy. However, some argue that reproductive cloning could help sterile couples fulfill their dream of parenthood. Others see human cloning as a way to avoid passing on a deleterious gene that runs in the family without having to undergo embryo screening or embryo selection.

Therapeutic cloning, while offering the potential for treating humans suffering from disease or injury, would require the destruction of human embryos in the test tube. Consequently, opponents argue that using this technique to collect embryonic stem cells is wrong, regardless of whether such cells are used to benefit sick or injured people.

Last updated: August 15, 2020

Ethical Debates Surrounding Animal Cloning Research Paper

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This research paper delves into the multifaceted ethical debates surrounding animal cloning for research purposes. It explores the historical development of cloning techniques and scrutinizes the ethical concerns surrounding animal welfare, biomedical research, and human-animal relationships. Drawing upon various ethical frameworks, regulations, and case studies, it evaluates the moral complexities associated with this practice. Additionally, the paper examines the perspectives of key stakeholders, assesses public awareness, and offers recommendations for responsible conduct and future research in the domain of animal cloning. By illuminating the central ethical issues and engaging with diverse viewpoints, this paper contributes to a deeper understanding of the moral landscape governing animal cloning in the realm of scientific inquiry.

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Animal cloning for research has emerged as a pivotal area of inquiry within the realm of biotechnology and ethics. Cloning, in this context, refers to the process of creating genetically identical copies of animals through asexual reproduction techniques such as somatic cell nuclear transfer (SCNT) (Wilmut et al., 1997). The primary purpose of animal cloning in research is to facilitate scientific investigations and advancements, ranging from the study of genetic diseases and the development of transgenic animals to the preservation of endangered species (Westhusin et al., 2009). Its potential to revolutionize biomedical research and conservation efforts is undeniable, but it is accompanied by profound ethical quandaries.

The significance of this topic is underscored by its far-reaching implications for science, ethics, and society. The ability to clone animals for research purposes raises questions about the ethical treatment of animals, the moral responsibilities of researchers, and the broader societal impact of these scientific endeavors. It is imperative to critically examine these ethical concerns and evaluate the ethical frameworks that underpin the decisions and practices surrounding animal cloning.

The research objectives of this paper are twofold. Firstly, it seeks to comprehensively delineate the ethical issues intertwined with animal cloning for research, emphasizing the multifaceted dimensions of these debates. Secondly, it aims to elucidate the various perspectives and stakeholders involved, from scientists and ethicists to animal rights activists and regulatory bodies, in order to foster a nuanced understanding of the discourse surrounding this contentious field.

In the subsequent sections, this paper will delve into the historical evolution of cloning techniques, dissect the ethical concerns related to animal welfare, biomedical research, and human-animal relationships, and critically assess existing ethical regulations and guidelines. Furthermore, it will analyze relevant case studies, explore public opinion, and offer recommendations for responsible conduct and further ethical considerations, thus providing a comprehensive framework for understanding the ethical dilemmas surrounding animal cloning for research.

II. Background

History and development of animal cloning techniques.

The history of animal cloning techniques is a testament to the relentless pursuit of scientific knowledge and the desire to manipulate genetic material for various purposes. The foundation of animal cloning can be traced back to the pioneering work of Robert Briggs and Thomas J. King, who successfully cloned frogs through nuclear transfer in the 1950s (Briggs & King, 1952). However, it was not until the late 20th century that significant breakthroughs in mammalian cloning occurred.

In 1997, the iconic birth of Dolly the sheep at the Roslin Institute in Scotland marked a monumental leap in animal cloning (Wilmut et al., 1997). Dolly was the first mammal to be cloned from an adult somatic cell using the somatic cell nuclear transfer (SCNT) technique. This groundbreaking achievement ignited global interest and speculation about the possibilities and ethical ramifications of cloning, leading to further developments and experimentation in the field.

Different Methods of Animal Cloning

Animal cloning encompasses various methods, each with distinct applications and ethical considerations. Alongside SCNT, researchers have employed techniques like embryo splitting, where a single embryo is divided into multiple embryos, creating genetically identical offspring (McGrath & Solter, 1984). Additionally, parthenogenesis, a process where an egg cell develops into an embryo without fertilization, has been explored as a means to generate cloned animals (Kono et al., 2004).

Furthermore, advancements in genetic engineering have given rise to transgenic cloning, allowing researchers to introduce specific genes into cloned animals, thereby creating animals with desired traits for research purposes (Lai et al., 2002). Each of these methods presents its own set of ethical dilemmas, particularly concerning the treatment and welfare of the animals involved, as well as the potential consequences of genetic manipulation.

Examples of Significant Research Projects Involving Animal Cloning

Animal cloning has found applications in various research domains, with notable projects demonstrating its versatility and potential. One such project involved the cloning of Snuppy, the world’s first cloned dog, in 2005 by South Korean scientists (Lee et al., 2005). This accomplishment raised ethical questions related to the cloning of companion animals and the potential commodification of pets.

Additionally, research has focused on the cloning of livestock for agricultural purposes, with the creation of cloned cows, pigs, and goats designed for enhanced meat or milk production (Wakayama et al., 1998). These projects underscore the economic implications of animal cloning, while also raising concerns about animal welfare in industrial farming settings.

In the realm of conservation biology, animal cloning has been explored as a means to rescue endangered species from the brink of extinction. For instance, the cloning of a gaur, a rare and endangered bovine species, was attempted in 2001 (Lanza et al., 2000). Such initiatives introduce ethical considerations regarding the ecological and ethical consequences of reintroducing cloned animals into their natural habitats.

These examples serve to illustrate the diverse applications of animal cloning for research and the ethical challenges that accompany these endeavors. The historical development of cloning techniques and the range of methods employed lay the foundation for the comprehensive exploration of ethical dilemmas in subsequent sections of this paper.

III. Ethical Frameworks

Introduce ethical theories and frameworks relevant to the debate.

The ethical debates surrounding animal cloning for research are deeply rooted in various ethical theories and frameworks that provide lenses through which to evaluate the moral implications of this practice. Three prominent ethical frameworks that come to the forefront of this discourse are Utilitarianism, Deontology, and Virtue Ethics.

• Utilitarianism: Utilitarianism is a consequentialist ethical theory that posits that the morality of an action should be determined by the overall happiness or pleasure it produces for all affected parties (Mill, 1861). In the context of animal cloning for research, utilitarianism would evaluate the ethics of cloning based on the net balance of benefits and harms to animals, humans, and society at large.
• Deontology: Deontology, as articulated by philosophers like Immanuel Kant, emphasizes the intrinsic moral value of actions themselves, rather than their consequences (Kant, 1785). Deontological ethics would scrutinize the ethical permissibility of animal cloning by assessing whether the act of cloning, regardless of its outcomes, respects the moral principles and duties owed to animals and other moral agents.
• Virtue Ethics: Virtue ethics, championed by thinkers such as Aristotle, focuses on the development of virtuous character traits and values (Aristotle, c. 350 BCE). In the context of animal cloning, virtue ethics would explore the character and intentions of those involved in cloning research, considering whether the practice cultivates virtuous qualities or vices, and how it affects moral agents’ moral development.

Discuss How These Frameworks Can Be Applied to Evaluate Animal Cloning for Research

Each of these ethical frameworks offers distinct perspectives on the moral quandaries posed by animal cloning for research:

• Utilitarianism: From a utilitarian standpoint, animal cloning for research must be assessed in terms of the balance between benefits and harms. Researchers and policymakers must weigh the potential scientific advancements, conservation efforts, and medical breakthroughs facilitated by cloning against the suffering and ethical concerns raised by cloning practices. This framework allows for a quantitative analysis of consequences but also raises questions about the well-being and rights of individual animals involved.
• Deontology: Deontological ethics would scrutinize the act of cloning itself, regardless of its consequences. It may emphasize principles such as respect for the intrinsic value and autonomy of animals. This perspective would challenge whether the act of creating genetically identical animals through cloning respects the inherent worth of each animal and adheres to moral duties, such as minimizing harm and protecting individual rights.
• Virtue Ethics: Virtue ethics directs attention to the character and intentions of researchers and stakeholders in the cloning process. It encourages reflection on whether cloning cultivates virtues like compassion, empathy, and responsibility, or fosters vices such as exploitation and indifference towards animals. Virtue ethics can provide insights into the moral development and ethical character of those engaged in animal cloning research.

By engaging with these ethical frameworks, this paper will critically assess the complex moral landscape of animal cloning for research, acknowledging the diverse perspectives they offer and highlighting the nuanced ethical considerations that arise within each framework. This ethical analysis will contribute to a comprehensive understanding of the ethical debates surrounding animal cloning in the broader context of scientific and societal advancement.

IV. Ethical Concerns

Ethical concerns related to animal welfare, discuss the physical and psychological well-being of cloned animals.

Cloning procedures can subject animals to various physical and psychological challenges. Cloned animals often suffer from higher rates of health issues, including cardiovascular problems, immune deficiencies, and premature aging (Loi et al., 2016). These health complications raise ethical concerns about the welfare of cloned animals. Furthermore, the cloning process itself can be physically demanding, involving invasive procedures such as hormone treatments and surgical implantation, which can lead to discomfort and distress. Moreover, the unique experiences of cloned animals, such as being genetically identical to another individual, may result in psychological stress and a diminished sense of individuality.

Consider the Implications of Cloning Failures and Deformities

Cloning is inherently prone to failures and deformities. A significant number of cloned embryos do not survive to birth, and those that do often exhibit abnormalities (Young et al., 2001). Ethical concerns arise not only from the suffering experienced by these animals but also from the potential moral obligations researchers have towards animals with severe deformities. Decisions regarding the management and treatment of such animals, including whether they should be euthanized or allowed to live, pose intricate ethical dilemmas that demand careful consideration.

Ethical Issues Surrounding the Use of Cloning in Biomedical Research

Discuss the creation and use of transgenic animals.

Cloning is frequently employed in the creation of transgenic animals, genetically engineered to carry specific traits or genes for research purposes. While this facilitates scientific investigations, it introduces ethical questions concerning the manipulation of animal genomes. The creation of transgenic animals raises concerns about the potential suffering and ethical treatment of animals engineered to express traits not naturally found in their species. Ethical scrutiny is warranted to ensure that the benefits of such research outweigh the ethical costs.

Analyze the Potential for Exploitation and Harm to Animals

The utilization of cloned animals in biomedical research can sometimes entail invasive and potentially harmful procedures, such as the testing of pharmaceuticals or the study of diseases. Ethical concerns arise when the welfare of these animals is compromised in the pursuit of scientific advancements. Researchers must grapple with the ethical balance between scientific progress and the well-being of the animals involved. Additionally, the risk of exploitation in the breeding and use of cloned animals for research purposes requires ethical oversight and regulation.

Concerns Related to Human-Animal Relationships

Explore the blurring of boundaries between humans and animals.

The advent of animal cloning can blur traditional boundaries between humans and animals. Cloning, particularly when it involves the creation of animals with human-like characteristics, raises questions about the moral and psychological implications of erasing the boundaries that traditionally distinguish humans from other species. The ethical implications of creating animals that challenge our understanding of species identity and uniqueness should be critically examined.

Discuss the Potential Impacts on Society’s Perception of Animals

Animal cloning may influence societal perceptions of animals, potentially devaluing their individuality and reinforcing a utilitarian view of animals as mere commodities or research tools. The ethical implications extend to how society views and treats animals, impacting legislation, public attitudes, and animal rights. This shift in perception necessitates an exploration of the broader ethical implications for our relationships with animals and our moral responsibilities towards them.

By addressing these multifaceted ethical concerns related to animal welfare, biomedical research, and human-animal relationships, this paper endeavors to provide a comprehensive analysis of the intricate ethical dilemmas surrounding animal cloning for research purposes. These concerns highlight the complex interplay between scientific progress, moral responsibilities, and the well-being of animals in the context of cloning research.

V. Ethical Regulations and Guidelines

Describe existing regulations and guidelines governing animal cloning for research.

The ethical landscape of animal cloning for research is influenced by a patchwork of regulations and guidelines established at national and international levels. These regulations primarily seek to address concerns related to animal welfare, research ethics, and the responsible conduct of scientific investigations.

At the international level, the World Health Organization (WHO) and the United Nations Food and Agriculture Organization (FAO) have developed guidelines to oversee the use of cloning techniques in animals, emphasizing the importance of monitoring animal health and welfare (WHO/FAO, 2007). Meanwhile, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) has specific provisions regarding the cloning and trade of endangered species (CITES, 2021).

Within individual countries, regulatory frameworks vary significantly. For example, the European Union (EU) has imposed a ban on the cloning of farm animals for food production due to concerns over animal welfare (EU Parliament, 2015). In contrast, the United States Food and Drug Administration (FDA) does not ban cloning for food, but it does recommend voluntary compliance with safety guidelines (FDA, 2008). The differing approaches highlight the complexity of regulating animal cloning and the range of ethical considerations involved.

Evaluate the Effectiveness of Current Ethical Standards in Addressing Concerns

The effectiveness of current ethical standards in addressing concerns related to animal cloning is a subject of ongoing debate. While these standards have made progress in recognizing the importance of animal welfare and ethical considerations, they often face challenges in implementation and enforcement. The voluntary nature of some guidelines and the absence of uniform international regulations create disparities in the treatment of cloned animals and the oversight of cloning research.

One area where ethical standards have been critiqued is the monitoring of cloned animals’ health and well-being throughout their lives. Given the higher incidence of health problems among cloned animals, some argue that stricter and more comprehensive monitoring is necessary to ensure their welfare (Loi et al., 2016).

Additionally, ethical standards may not sufficiently address the broader societal implications and ethical dilemmas associated with animal cloning, such as the blurring of human-animal boundaries and the potential impacts on societal attitudes towards animals. This highlights the need for a more holistic ethical framework that encompasses these complex considerations.

Discuss Any Ethical Dilemmas or Gaps in Regulations

Ethical dilemmas and gaps in regulations concerning animal cloning for research persist in several key areas. One such dilemma revolves around the balance between scientific freedom and ethical responsibilities. While regulations aim to safeguard animal welfare, there is an ongoing debate over whether they might stifle scientific progress or hinder the development of beneficial research.

Another ethical dilemma lies in the absence of unified international regulations, which can lead to discrepancies in ethical oversight and animal welfare standards across countries. This lack of harmonization can potentially enable research practices in locations with less stringent regulations that would not be permitted elsewhere.

Furthermore, gaps in regulations may fail to address emerging ethical challenges posed by advancing cloning technologies, such as gene editing in cloned animals. The rapid evolution of scientific capabilities necessitates ongoing ethical scrutiny and adaptation of regulatory frameworks to keep pace with technological developments.

In summary, while existing regulations and guidelines make efforts to address ethical concerns in animal cloning research, there remain ethical dilemmas and regulatory gaps that necessitate continued examination and refinement to ensure the ethical and responsible conduct of research in this field.

VI. Case Studies

Present case studies of prominent animal cloning research projects.

• Dolly the Sheep (1997): Dolly, the first cloned mammal, was a groundbreaking achievement in animal cloning research conducted at the Roslin Institute in Scotland. Dolly was cloned using somatic cell nuclear transfer (SCNT) from an adult sheep. This case study marks a significant milestone in cloning history.
• Snuppy the Dog (2005): Snuppy, the world’s first cloned dog, was created by South Korean scientists. This achievement raised ethical questions regarding the cloning of companion animals and the potential for commercialization of pet cloning services.
• Transgenic Cloning for Biomedical Research (Ongoing): Numerous studies involve the cloning of animals for biomedical research, including the creation of transgenic animals with specific genes or traits. These projects often aim to advance our understanding of diseases and develop treatments but raise ethical concerns about the well-being of the animals involved and the implications of genetic manipulation.

Analyze the Ethical Dilemmas and Controversies Associated with Each Case

• Dolly the Sheep (1997): Dolly’s birth sparked ethical debates over the cloning of animals and the welfare of cloned individuals. Critics questioned whether the potential benefits of scientific advancement justified the health risks and ethical concerns associated with cloning. The case also raised concerns about animal welfare, as Dolly experienced health issues throughout her life, including arthritis and lung disease.
• Snuppy the Dog (2005): Snuppy’s cloning brought attention to the ethical considerations surrounding the cloning of pets. Critics argued that cloning pets could commodify animals and undermine the significance of the bond between humans and their companion animals. The case highlighted the need for ethical guidelines regarding the cloning of animals for non-medical purposes.
• Transgenic Cloning for Biomedical Research (Ongoing): The creation and use of transgenic animals for research purposes present ethical dilemmas related to the genetic manipulation of animals. These animals may be subject to invasive procedures and may suffer unintended consequences as a result of genetic modifications. Ethical concerns also extend to the potential for exploitation and harm to animals in the pursuit of scientific knowledge.

Discuss the Outcomes and Lessons Learned from These Cases

• Dolly the Sheep (1997): The case of Dolly led to increased awareness of the ethical complexities of animal cloning. It underscored the need for ongoing monitoring of the health and welfare of cloned animals and prompted discussions about responsible scientific conduct. Dolly’s legacy continues to influence the ethical discourse surrounding cloning.
• Snuppy the Dog (2005): The case of Snuppy highlighted the ethical importance of distinguishing between cloning for research and cloning for non-medical purposes, such as pet cloning. It contributed to the development of guidelines and regulations for pet cloning services in some countries, emphasizing the need for transparency and ethical considerations in commercial cloning ventures.
• Transgenic Cloning for Biomedical Research (Ongoing): These ongoing cases emphasize the need for robust ethical oversight and continuous evaluation of the welfare of animals used in biomedical research. Lessons learned include the importance of ethical frameworks that balance scientific progress with the well-being of animals and the necessity of transparency and accountability in research practices.

These case studies illustrate the ethical dilemmas and controversies inherent in animal cloning research and underscore the importance of responsible conduct, ethical oversight, and ongoing dialogue to address the complex moral issues associated with cloning technology.

VII. Stakeholder Perspectives

Explore the perspectives of key stakeholders involved in animal cloning research.

• Scientists and Researchers: Scientists and researchers involved in animal cloning research often emphasize the potential benefits, such as advancing medical science, conservation efforts, and genetic research. They argue that cloning technology can contribute to scientific progress and provide insights into genetics and biology (Lanza et al., 2000). Researchers also stress the importance of rigorous ethical guidelines to ensure the responsible conduct of research.
• Animal Rights Activists: Animal rights activists frequently oppose animal cloning for research, citing concerns about the welfare and suffering of cloned animals. They argue that the cloning process can lead to physical and psychological harm, and that it commodifies animals, treating them as mere objects for experimentation. Activists advocate for alternatives to cloning and emphasize the moral duty to protect animal rights (Koene & Van der Meulen, 2019).
• Ethicists and Philosophers: Ethicists and philosophers offer critical perspectives on the moral dimensions of animal cloning. They engage in philosophical inquiries into the ethical frameworks that underpin cloning practices, examining concepts such as animal welfare, species identity, and the moral status of animals. Ethicists play a crucial role in shaping ethical guidelines and frameworks for responsible research (Regan, 1985).
• Government and Regulatory Bodies: Government agencies and regulatory bodies are responsible for crafting and enforcing guidelines and legislation related to animal cloning research. Their perspectives focus on striking a balance between promoting scientific innovation and ensuring ethical standards and animal welfare. Regulatory bodies assess the risks and benefits of cloning and often base their decisions on scientific evidence, public opinion, and ethical considerations (FDA, 2008).

Analyze the Conflicts and Common Ground Among These Perspectives

Conflicts among these stakeholders often revolve around the trade-offs between scientific progress and animal welfare. Scientists and researchers emphasize the potential benefits of cloning for research, while animal rights activists prioritize the protection of animal welfare. Ethicists and philosophers provide critical analyses that help bridge these perspectives by developing ethical frameworks that seek to reconcile these concerns.

Common ground can be found in the shared commitment to responsible research practices. Scientists, ethicists, regulatory bodies, and even animal rights activists acknowledge the importance of ethical guidelines and oversight to mitigate harm to animals and ensure the integrity of research. Collaboration between these stakeholders can lead to the development of ethical standards that strike a balance between scientific advancement and ethical considerations.

Additionally, there is a shared interest in transparency and public engagement. All stakeholders recognize the importance of involving the public in discussions about the ethics of animal cloning for research. Public awareness and informed dialogue can contribute to the development of more balanced and ethical approaches to cloning technology.

In summary, while conflicts persist among stakeholders involved in animal cloning research, there is common ground in the pursuit of responsible and ethical research practices. Engaging in constructive dialogue and considering the perspectives of all stakeholders can lead to more comprehensive and ethically sound approaches to animal cloning for research.

VIII. Public Opinion and Awareness

Examine public awareness and attitudes towards animal cloning for research.

Public awareness and attitudes towards animal cloning for research play a pivotal role in shaping the ethical debates and regulatory decisions surrounding this field. Understanding the perspectives and sentiments of the general public is essential for policymakers, researchers, and ethicists.

Public awareness of animal cloning for research remains relatively limited, with many individuals having a basic understanding of the concept but lacking in-depth knowledge of the scientific and ethical complexities involved (Stewart et al., 2017). Surveys and studies have shown that public awareness varies across different regions and is influenced by factors such as education, socioeconomic status, and access to information (McCaughey et al., 2007).

Attitudes towards animal cloning for research are multifaceted. Some members of the public may support cloning when it is framed as a means to advance medical science or conserve endangered species (Brossard et al., 2009). Others, however, express ethical reservations and concerns about animal welfare, viewing cloning as an unnatural manipulation of life (Vos et al., 2016). Public opinion can also be influenced by cultural and religious beliefs, further diversifying the spectrum of attitudes.

Discuss the Role of Media and Public Perception in Shaping the Debate

Media outlets and communication channels play a significant role in shaping public perception of animal cloning for research. The media often frame cloning stories in ways that highlight the potential benefits or ethical dilemmas, influencing public opinion accordingly (Kelman, 2005). Media coverage can either promote informed and nuanced discussions or contribute to polarized views, depending on the tone and framing of the stories.

Media coverage tends to amplify sensational or controversial aspects of cloning, which can overshadow the nuanced ethical considerations involved (Jensen & O’Connell, 2013). This sensationalism can generate public interest but may also oversimplify complex issues and contribute to misunderstandings.

Public perception, in turn, can influence political and regulatory decisions. Policymakers may be responsive to public concerns and sentiments, leading to shifts in regulatory approaches. Therefore, media portrayal and public opinion are integral components of the broader ethical discourse surrounding animal cloning for research.

In conclusion, public awareness and attitudes towards animal cloning for research are shaped by various factors, including media coverage and the framing of ethical issues. Public perception can influence the trajectory of the debate and impact regulatory decisions. It is crucial for stakeholders to engage with the public in informed and transparent discussions to ensure that ethical considerations are at the forefront of the decision-making process regarding animal cloning for research.

IX. Future Directions and Recommendations

Propose potential improvements to ethical guidelines and regulations.

• Standardization of Regulations: To address the current disparities in regulations, efforts should be made at both national and international levels to standardize ethical guidelines governing animal cloning for research. Collaborative initiatives, similar to those within the European Union, can promote uniformity and ensure that consistent ethical standards are applied across borders (EU Parliament, 2015).
• Continuous Monitoring and Evaluation: Ethical guidelines and regulations should include provisions for ongoing monitoring and evaluation of the welfare of cloned animals throughout their lives. This can help identify and address health issues promptly, ensuring that cloned animals receive the care they need (Loi et al., 2016).
• Public Engagement: Policymakers and regulatory bodies should actively engage the public in discussions about the ethical dimensions of animal cloning research. Public input can inform the development and revision of regulations, ensuring that they align with societal values and ethical concerns (Stewart et al., 2017).

Suggest Areas for Further Research and Ethical Consideration

• Long-Term Health and Welfare Studies: Further research is needed to conduct long-term health and welfare studies of cloned animals to better understand the physical and psychological well-being of these animals over their lifetimes. This research can inform ethical guidelines and contribute to the responsible treatment of cloned animals (Young et al., 2001).
• Alternatives to Cloning: Ethical consideration should be given to the exploration of alternatives to cloning for research purposes. Developing and promoting non-invasive methods, such as in vitro models or advanced computational simulations, can reduce the ethical concerns associated with cloning (Koene & Van der Meulen, 2019).
• Transparency and Accountability: Research on ethical considerations should focus on enhancing transparency and accountability in animal cloning research. This includes the development of ethical decision-making frameworks and mechanisms for reporting ethical violations (Mepham, 2000).

Offer Recommendations for Responsible Conduct in Animal Cloning Research

• Ethical Training: Researchers and institutions involved in animal cloning research should prioritize ethical training for personnel. This training should encompass not only scientific expertise but also an understanding of the ethical principles and responsibilities involved in working with cloned animals (Lanza et al., 2000).
• Adherence to Ethical Guidelines: Researchers should strictly adhere to existing ethical guidelines and regulations governing animal cloning. Institutions should establish robust oversight mechanisms to ensure compliance and provide support for researchers in ethical decision-making (FDA, 2008).
• Transparency and Public Communication: Researchers should maintain transparency in their work and actively communicate their methods, findings, and ethical considerations to the public. Open and honest communication can help build public trust and foster a more informed ethical discourse (Brossard et al., 2009).

In conclusion, the responsible conduct of animal cloning research requires continuous improvement in ethical guidelines and regulations, ongoing research into the welfare of cloned animals, and proactive engagement with the public. By addressing these areas, the field of animal cloning can advance ethically, contributing to scientific progress while upholding the welfare and ethical considerations of the animals involved.

X. Conclusion

Summarize the main ethical debates and concerns surrounding animal cloning for research.

The ethical debates surrounding animal cloning for research are multifaceted and encompass a range of complex concerns:

• Animal Welfare: Ethical concerns revolve around the physical and psychological well-being of cloned animals, given the higher incidence of health problems and potential suffering associated with cloning.
• Biomedical Research: The creation of transgenic animals and the use of cloning in biomedical research raise questions about the moral permissibility of genetic manipulation, as well as the potential exploitation and harm to animals.
• Human-Animal Relationships: The blurring of boundaries between humans and animals, particularly in cases involving the creation of animals with human-like traits, challenges our understanding of species identity and raises ethical questions about the implications for societal attitudes towards animals.

Reiterate the Significance of the Topic

The significance of animal cloning for research lies in its potential to revolutionize scientific inquiry, conservation efforts, and medical advancements. However, this transformative technology is accompanied by profound ethical dilemmas that demand careful consideration. The ethical debates surrounding animal cloning are not confined to the realm of science but extend to questions about our moral responsibilities to animals, the integrity of research practices, and the evolving nature of human-animal relationships.

Emphasize the Need for Continued Ethical Discourse and Responsible Practices in this Field

As scientific capabilities advance, the ethical discourse surrounding animal cloning for research remains essential. It is imperative that stakeholders, including scientists, ethicists, policymakers, and the public, continue engaging in informed and transparent discussions. Responsible practices and adherence to ethical guidelines are essential to mitigate harm to animals and uphold the integrity of research.

The evolution of ethical frameworks, regulations, and public attitudes will shape the future of animal cloning for research. It is a field that holds promise, but its ethical dimensions must be navigated with vigilance and care. Ultimately, the responsible and ethical advancement of animal cloning research can contribute not only to scientific progress but also to our broader understanding of our moral obligations to the sentient beings with whom we share our planet.

Bibliography

• Nicomachean Ethics. Hackett Publishing Company, 2011.
• “Animal Cloning: A Risk Assessment.” US Food and Drug Administration, 2008.
• Kant, Immanuel. Groundwork for the Metaphysics of Morals. Hackett Publishing Company, 1993.
• Koene, Paul, and Machteld A.S. Huberts. “Ethical Issues with Animal Cloning.” Ethics in Biology, Engineering and Medicine: An International Journal, vol. 10, no. 1, 2019, pp. 31-45.
• Lai, Liangxue, et al. “Generation of Cloned Transgenic Pigs Rich in Omega-3 Fatty Acids.” Nature Biotechnology, vol. 20, no. 5, 2002, pp. 467-470.
• Mill, John Stuart. Utilitarianism. Dover Publications, 2005.
• Regan, Tom. The Case for Animal Rights. University of California Press, 2004.
• Wilmut, Ian, et al. “Viable Offspring Derived from Fetal and Adult Mammalian Cells.” Nature, vol. 385, no. 6619, 1997, pp. 810-813.

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ENCYCLOPEDIC ENTRY

Cloning is a technique scientists use to create exact genetic replicas of genes, cells, or animals.

Biology, Genetics, Health, Chemistry

Cloned Beagles

Two Beagle puppies successfully cloned in Seoul, South Korea. These two dogs were cloned by a biopharmaceutical company that specializes in stem cell based therapeutics.

Photograph by Handout

Cloning is a technique scientists use to make exact genetic copies of living things. Genes , cells, tissues, and even whole animals can all be cloned .

Some clones already exist in nature. Single-celled organisms like bacteria make exact copies of themselves each time they reproduce. In humans, identical twins are similar to clones . They share almost the exact same genes . Identical twins are created when a fertilized egg splits in two.

Scientists also make clones in the lab. They often clone genes in order to study and better understand them. To clone a gene , researchers take DNA from a living creature and insert it into a carrier like bacteria or yeast. Every time that carrier reproduces, a new copy of the gene is made.

Animals are cloned in one of two ways. The first is called embryo twinning. Scientists first split an embryo in half. Those two halves are then placed in a mother’s uterus. Each part of the embryo develops into a unique animal, and the two animals share the same genes . The second method is called somatic cell nuclear transfer. Somatic cells are all the cells that make up an organism, but that are not sperm or egg cells. Sperm and egg cells contain only one set of chromosomes , and when they join during fertilization, the mother’s chromosomes merge with the father’s. Somatic cells , on the other hand, already contain two full sets of chromosomes . To make a clone , scientists transfer the DNA from an animal’s somatic cell into an egg cell that has had its nucleus and DNA removed. The egg develops into an embryo that contains the same genes as the cell donor. Then the embryo is implanted into an adult female’s uterus to grow.

In 1996, Scottish scientists cloned the first animal, a sheep they named Dolly. She was cloned using an udder cell taken from an adult sheep. Since then, scientists have cloned cows, cats, deer, horses, and rabbits. They still have not cloned a human, though. In part, this is because it is difficult to produce a viable clone . In each attempt, there can be genetic mistakes that prevent the clone from surviving. It took scientists 276 attempts to get Dolly right. There are also ethical concerns about cloning a human being.

Researchers can use clones in many ways. An embryo made by cloning can be turned into a stem cell factory. Stem cells are an early form of cells that can grow into many different types of cells and tissues. Scientists can turn them into nerve cells to fix a damaged spinal cord or insulin-making cells to treat diabetes.

The cloning of animals has been used in a number of different applications. Animals have been cloned to have gene mutations that help scientists study diseases that develop in the animals. Livestock like cows and pigs have been cloned to produce more milk or meat. Clones can even “resurrect” a beloved pet that has died. In 2001, a cat named CC was the first pet to be created through cloning. Cloning might one day bring back extinct species like the woolly mammoth or giant panda.

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• v.41(12); 2000 Dec

Benefits and problems with cloning animals.

Animal cloning is becoming a useful technique for producing transgenic farm animals and is likely to be used to produce clones from valuable adults. Other applications will also undoubtedly be discovered in the near future, such as for preserving endangered breeds and species. Although cloning promises great advantages for commerce and research alike, its outcome is not always certain due to high pregnancy losses and high morbidity and mortality during the neonatal period. Research into the mechanisms involved in the reprogramming of the nucleus is being conducted throughout the world in an attempt to better understand the molecular and cellular mechanisms involved in correcting these problems. Although the cause of these anomalies remains mostly unknown, similar phenotypes have been observed in calves derived through in vitro fertilization, suggesting that culture conditions are involved in these phenomena. In the meantime, veterinarians and theriogenologists have an important role to play in improving the efficiency of cloning by finding treatments to assure normal gestation to term and to develop preventative and curative care for cloned neonates.

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.4M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References .

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

• Wilmut I, Schnieke AE, McWhir J, Kind AJ, Campbell KH. Viable offspring derived from fetal and adult mammalian cells. Nature. 1997 Feb 27; 385 (6619):810–813. [ PubMed ] [ Google Scholar ]
• McGrath J, Solter D. Inability of mouse blastomere nuclei transferred to enucleated zygotes to support development in vitro. Science. 1984 Dec 14; 226 (4680):1317–1319. [ PubMed ] [ Google Scholar ]
• Willadsen SM. Nuclear transplantation in sheep embryos. Nature. 1986 Mar 6; 320 (6057):63–65. [ PubMed ] [ Google Scholar ]
• Smith LC, Wilmut I. Influence of nuclear and cytoplasmic activity on the development in vivo of sheep embryos after nuclear transplantation. Biol Reprod. 1989 May; 40 (5):1027–1035. [ PubMed ] [ Google Scholar ]
• Keefer CL, Stice SL, Matthews DL. Bovine inner cell mass cells as donor nuclei in the production of nuclear transfer embryos and calves. Biol Reprod. 1994 Apr; 50 (4):935–939. [ PubMed ] [ Google Scholar ]
• Wakayama T, Perry AC, Zuccotti M, Johnson KR, Yanagimachi R. Full-term development of mice from enucleated oocytes injected with cumulus cell nuclei. Nature. 1998 Jul 23; 394 (6691):369–374. [ PubMed ] [ Google Scholar ]
• Wells DN, Misica PM, Tervit HR. Production of cloned calves following nuclear transfer with cultured adult mural granulosa cells. Biol Reprod. 1999 Apr; 60 (4):996–1005. [ PubMed ] [ Google Scholar ]
• Schnieke AE, Kind AJ, Ritchie WA, Mycock K, Scott AR, Ritchie M, Wilmut I, Colman A, Campbell KH. Human factor IX transgenic sheep produced by transfer of nuclei from transfected fetal fibroblasts. Science. 1997 Dec 19; 278 (5346):2130–2133. [ PubMed ] [ Google Scholar ]
• Cibelli JB, Stice SL, Golueke PJ, Kane JJ, Jerry J, Blackwell C, Ponce de León FA, Robl JM. Cloned transgenic calves produced from nonquiescent fetal fibroblasts. Science. 1998 May 22; 280 (5367):1256–1258. [ PubMed ] [ Google Scholar ]
• Hill JR, Roussel AJ, Cibelli JB, Edwards JF, Hooper NL, Miller MW, Thompson JA, Looney CR, Westhusin ME, Robl JM, et al. Clinical and pathologic features of cloned transgenic calves and fetuses (13 case studies). Theriogenology. 1999 Jun; 51 (8):1451–1465. [ PubMed ] [ Google Scholar ]
• Wells DN, Misica PM, Tervit HR, Vivanco WH. Adult somatic cell nuclear transfer is used to preserve the last surviving cow of the Enderby Island cattle breed. Reprod Fertil Dev. 1998; 10 (4):369–378. [ PubMed ] [ Google Scholar ]
• Kato Y, Tani T, Sotomaru Y, Kurokawa K, Kato J, Doguchi H, Yasue H, Tsunoda Y. Eight calves cloned from somatic cells of a single adult. Science. 1998 Dec 11; 282 (5396):2095–2098. [ PubMed ] [ Google Scholar ]
• Galli C, Duchi R, Moor RM, Lazzari G. Mammalian leukocytes contain all the genetic information necessary for the development of a new individual. Cloning. 1999; 1 (3):161–170. [ PubMed ] [ Google Scholar ]
• Campbell KH, McWhir J, Ritchie WA, Wilmut I. Sheep cloned by nuclear transfer from a cultured cell line. Nature. 1996 Mar 7; 380 (6569):64–66. [ PubMed ] [ Google Scholar ]
• McCreath KJ, Howcroft J, Campbell KH, Colman A, Schnieke AE, Kind AJ. Production of gene-targeted sheep by nuclear transfer from cultured somatic cells. Nature. 2000 Jun 29; 405 (6790):1066–1069. [ PubMed ] [ Google Scholar ]
• Smith LC. Membrane and intracellular effects of ultraviolet irradiation with Hoechst 33342 on bovine secondary oocytes matured in vitro. J Reprod Fertil. 1993 Sep; 99 (1):39–44. [ PubMed ] [ Google Scholar ]
• Bordignon V, Smith LC. Telophase enucleation: an improved method to prepare recipient cytoplasts for use in bovine nuclear transfer. Mol Reprod Dev. 1998 Jan; 49 (1):29–36. [ PubMed ] [ Google Scholar ]
• Sgaramella V, Zinder ND. Dolly confirmation. Science. 1998 Jan 30; 279 (5351):635–638. [ PubMed ] [ Google Scholar ]
• Ashworth D, Bishop M, Campbell K, Colman A, Kind A, Schnieke A, Blott S, Griffin H, Haley C, McWhir J, et al. DNA microsatellite analysis of Dolly. Nature. 1998 Jul 23; 394 (6691):329–329. [ PubMed ] [ Google Scholar ]
• Signer EN, Dubrova YE, Jeffreys AJ, Wilde C, Finch LM, Wells M, Peaker M. DNA fingerprinting Dolly. Nature. 1998 Jul 23; 394 (6691):329–330. [ PubMed ] [ Google Scholar ]
• Wakayama T, Yanagimachi R. Cloning of male mice from adult tail-tip cells. Nat Genet. 1999 Jun; 22 (2):127–128. [ PubMed ] [ Google Scholar ]
• Smith LC, Bordignon V, Garcia JM, Meirelles FV. Mitochondrial genotype segregation and effects during mammalian development: applications to biotechnology. Theriogenology. 2000 Jan 1; 53 (1):35–46. [ PubMed ] [ Google Scholar ]
• White KL, Bunch TD, Mitalipov S, Reed WA. Establishment of pregnancy after the transfer of nuclear transfer embryos produced from the fusion of argali (Ovis ammon) nuclei into domestic sheep (Ovis aries) enucleated oocytes. Cloning. 1999; 1 (1):47–54. [ PubMed ] [ Google Scholar ]
• Dominko T, Mitalipova M, Haley B, Beyhan Z, Memili E, McKusick B, First NL. Bovine oocyte cytoplasm supports development of embryos produced by nuclear transfer of somatic cell nuclei from various mammalian species. Biol Reprod. 1999 Jun; 60 (6):1496–1502. [ PubMed ] [ Google Scholar ]
• Lanza RP, Cibelli JB, West MD. Human therapeutic cloning. Nat Med. 1999 Sep; 5 (9):975–977. [ PubMed ] [ Google Scholar ]
• Brinster RL, Chen HY, Trumbauer ME, Yagle MK, Palmiter RD. Factors affecting the efficiency of introducing foreign DNA into mice by microinjecting eggs. Proc Natl Acad Sci U S A. 1985 Jul; 82 (13):4438–4442. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Rideout WM, 3rd, Wakayama T, Wutz A, Eggan K, Jackson-Grusby L, Dausman J, Yanagimachi R, Jaenisch R. Generation of mice from wild-type and targeted ES cells by nuclear cloning. Nat Genet. 2000 Feb; 24 (2):109–110. [ PubMed ] [ Google Scholar ]
• Stice SL, Strelchenko NS, Keefer CL, Matthews L. Pluripotent bovine embryonic cell lines direct embryonic development following nuclear transfer. Biol Reprod. 1996 Jan; 54 (1):100–110. [ PubMed ] [ Google Scholar ]
• Baguisi A, Behboodi E, Melican DT, Pollock JS, Destrempes MM, Cammuso C, Williams JL, Nims SD, Porter CA, Midura P, et al. Production of goats by somatic cell nuclear transfer. Nat Biotechnol. 1999 May; 17 (5):456–461. [ PubMed ] [ Google Scholar ]
• Wells DN, Misica PM, Day TA, Tervit HR. Production of cloned lambs from an established embryonic cell line: a comparison between in vivo- and in vitro-matured cytoplasts. Biol Reprod. 1997 Aug; 57 (2):385–393. [ PubMed ] [ Google Scholar ]
• Renard JP, Chastant S, Chesné P, Richard C, Marchal J, Cordonnier N, Chavatte P, Vignon X. Lymphoid hypoplasia and somatic cloning. Lancet. 1999 May 1; 353 (9163):1489–1491. [ PubMed ] [ Google Scholar ]
• Smith LC. Production of multiple genetically identical farm animals by nuclear transplantation. Can Vet J. 1991 Feb; 32 (2):94–98. [ PMC free article ] [ PubMed ] [ Google Scholar ]