Thread: Cloning
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Old Friday, December 22, 2006
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Cloning Ethics

Is Cloning Wrong or Right?
Can we and should we clone humans?

Wrong

The biggest problem with the use of cloning on a large is scale is the decline in genetic diversity. Think about it, if everyone has the same genetic material, what happens if we lose the ability to clone. We would have to resort to natural reproduction, causing us to inbreed, which will cause many problems. Also, if a population of organisms has the same genetic information, then the disease would wipe out the entire population. Helping endangered species by cloning will not help the problem. Currently, zoologists and environmentalists trying to save endangered species are not so much having trouble keeping population numbers up, but not having any animals to breed that are not cousins. The technique of nuclear transfer is also early in its developmental stages. Thus, errors are occurring when scientists carry out the procedure. For instance, it took 277 tries to produce Dolly, and Roslin scientists produced many lambs with abnormalities. If we tried to clone endangered species we could possibly kill the last females integral to the survival of a species. This may be the main reason science is holding out on cloning humans.

Right

The goals and purposes for cloning range from making copies of those that have deceased to better engineering the offspring in humans and animals. Cloning could also directly offer a means of curing diseases or a technique that could extend means to acquiring new data for the sciences of embryology and how organisms develop as a whole over time. Currently, the agricultural industry demands nuclear transfer to produce better livestock. Cloning could massively improve the agricultural industry as the technique of nuclear transfer improves. Currently, change in the phenotype of livestock is accomplished by bombarding embryos of livestock with genes that produce livestock with preferred traits. However, this technique is not efficient as only 5 percent of the offspring express the traits. Scientists can easily genetically alter adult cells. Thus, cloning from an adult cell would make it easier to alter the genetic material. The goal of transgenic livestock is to produce livestock with ideal characteristics for the agricultural industry and to be able to manufacture biological products such as proteins for humans. Farmers are attempting to produce transgenic livestock already, but not efficiently, due to the minimal ability to alter embryos genetically, as stated above. Researchers can harvest and grow adult cells in large amounts compared to embryos. Scientists can then genetically alter these cells and find which ones did transform and then clone only those cells.

Can we and should we clone humans?

Cloning humans has recently become a possibility that seems much more feasible in today's society than it was twenty years ago. It is a method that involves the production of a group of identical cells or organisms that all derive from a single individual. It is not known when or how cloning humans really became a possibility, but it is known that there are two possible ways that we can clone humans. The first way involves splitting an embryo into several halves and creating many new individuals from that embryo. The second method of cloning a human involves taking cells from an already existing human being and cloning them, in turn creating other individuals that are identical to that particular person. With these two methods almost at our fingertips, we must ask ourselves two very important questions: Can we do this, and should we? There is no doubt that many problems involving the technological and ethical sides of this issue will arise and will be virtually impossible to avoid, but the overall idea of cloning humans is one that we should accept as a possible reality for the future.
Embryonic cloning could be a valuable tool for the studying of human development, genetically modifying embryos, and investigating new transplant technologies. Using cloning to produce offspring for the sake of their organs is an issue that we must also face and question whether or not it is morally right. No one will say that it is okay to kill a human being for the sake of their organs, but many have no objection to cloning thousands of individuals that look alike. Technology seems to take away many of the morals that we have worked so hard to install in society. Most people only seem to want to cater to their own needs and do not bother to consider the consequences that society and the clone may have to face.
How can cloning technologies be used?
Recombinant DNA technology is important for learning about other related technologies, such as gene therapy, genetic engineering of organisms, and sequencing genomes. Gene therapy can be used to treat certain genetic conditions by introducing virus vectors that carry corrected copies of faulty genes into the cells of a host organism. Genes from different organisms that improve taste and nutritional value or provide resistance to particular types of disease can be used to genetically engineer food crops. With genome sequencing, fragments of chromosomal DNA must be inserted into different cloning vectors to generate fragments of an appropriate size for sequencing.
If the low success rates can be improved (Dolly was only one success out of 276 tries), reproductive cloning can be used to develop efficient ways to reliably reproduce animals with special qualities. For example, drug-producing animals or animals that have been genetically altered to serve as models for studying human disease could be mass-produced.
Reproductive cloning also could be used to repopulate endangered animals or animals that are difficult to breed. In 2001, the first clone of an endangered wild animal was born, a wild ox called a gaur. The young gaur died from an infection about 48 hours after its birth. In 2001, scientists in Italy reported the successful cloning of a healthy baby mouflon, an endangered wild sheep. The cloned mouflon is living at a wildlife center in Sardinia. Other endangered species that are potential candidates for cloning include the African bongo antelope, the Sumatran tiger, and the giant panda. Cloning extinct animals presents a much greater challenge to scientists because the egg and the surrogate needed to create the cloned embryo would be of a species different from the clone.
Therapeutic cloning technology may some day be used in humans to produce whole organs from single cells or to produce healthy cells that can replace damaged cells in degenerative diseases such as Alzheimer's or Parkinson's. Much work still needs to be done before therapeutic cloning can become a realistic option for the treatment of disorders.
Can organs be cloned for use in transplants?
Scientists hope that one day therapeutic cloning can be used to generate tissues and organs for transplants. To do this, DNA would be extracted from the person in need of a transplant and inserted into an enucleated egg. After the egg containing the patient's DNA starts to divide, embryonic stem cells that can be transformed into any type of tissue would be harvested. The stem cells would be used to generate an organ or tissue that is a genetic match to the recipient. In theory, the cloned organ could then be transplanted into the patient without the risk of tissue rejection. If organs could be generated from cloned human embryos, the need for organ donation could be significantly reduced.
Many challenges must be overcome before "cloned organ" transplants become reality. More effective technologies for creating human embryos, harvesting stem cells, and producing organs from stem cells would have to be developed. In 2001, scientists with the biotechnology company Advanced Cell Technology (ACT) reported that they had cloned the first human embryos; however, the only embryo to survive the cloning process stopped developing after dividing into six cells. In February 2002, scientists with the same biotech company reported that they had successfully transplanted kidney-like organs into cows. The team of researchers created a cloned cow embryo by removing the DNA from an egg cell and then injecting the DNA from the skin cell of the donor cow's ear. Since little is known about manipulating embryonic stem cells from cows, the scientists let the cloned embryos develop into fetuses. The scientists then harvested fetal tissue from the clones and transplanted it into the donor cow. In the three months of observation following the transplant, no sign of immune rejection was observed in the transplant recipient.
Another potential application of cloning to organ transplants is the creation of genetically modified pigs from which organs suitable for human transplants could be harvested . The transplant of organs and tissues from animals to humans is called xenotransplantation.
Why pigs? Primates would be a closer match genetically to humans, but they are more difficult to clone and have a much lower rate of reproduction. Of the animal species that have been cloned successfully, pig tissues and organs are more similar to those of humans. To create a "knock-out" pig, scientists must inactivate the genes that cause the human immune system to reject an implanted pig organ. The genes are knocked out in individual cells, which are then used to create clones from which organs can be harvested. In 2002, a British biotechnology company reported that it was the first to produce "double knock-out" pigs that have been genetically engineered to lack both copies of a gene involved in transplant rejection. More research is needed to study the transplantation of organs from "knock-out" pigs to other animals.
The Potential Advantages and Disadvantages of Cloning:

Advantages:
With this controversial issue, the possibilities of advantages and disadvantages must be discussed. There are several advantages to the cloning of animals and to the cloning of human cells. Along with each of the advantages, however, there are disadvantages, risks, and warnings.
There are five important reasons why animal cloning might be useful: (1) to generate groups of genetically identical animals for research purposes; (2) to rapidly propagate desirable animal stocks; (3) to improve the efficiency of generating and propagating transgenic livestock; (4) to produce targeted genetic alterations in domestic animals; (5) to pursue basic knowledge about cell differentiation.
Cloning animals for research purposes is attractive to many scientists, because the experimental variation that often occurs with genetic differences is eliminated. This process is limited in its usefulness, however, because keeping a homozygous line is going to be difficult. Also, the overall process promises to be expensive for most animals.
Having a speedy method to breed favorable livestock has great commercial importance. Nuclear transfer may be the wave of the future to rapidly produce desirable stocks of animals. The ultimate consequences could be dangerous, however, because genetic diversity could be eliminated. Strict regulation of cloning would ensure that this would not happen, though.
The improved generation and propagation of transgenic livestock becomes of interest to the pharmaceutical and medical world. Genetically altering farm animals by the introduction and expression of genes from other species proves to be a useful technology for the future. For example, the milk of livestock animals can be modified to contain large amounts of pharmaceutically important proteins such as insulin or factor VIII for treatment of human disease by expressing human genes in the mammary gland. Also, transgenic animals could become useful for organ transplantation into humans.
Generating targeted gene alterations in domestic animals can be helpful in studying mutations of genes in a very controlled manner. Gene targeting approaches can also be used to ensure correct tissue-specific expression of foreign genes and to suppress the expression of genes in inappropriate tissues. It could also be used to directly alter normal genes, which could influence animal health and productivity.
Basic research on cell differentiation has come about with the arrival of Dolly. Developmental biologists will want to know which genes are reprogrammed, when they are expressed, and in what order. This may or may not shed some light on the specialization that occurs during the development of therapies to treat human disease.
The agricultural industry could reek the benefits of this new technology by having the ability to produce multiple identical copies of a cow that produces a lot of mile, a sheep that produces a lot of wool, and so on. They could create an elite stock of farm animals.
The most exciting prospect here is to modify a sheep CTFR gene to create a model of cystic fibrosis (CF) for gene therapy. In a classy move, Ian Wilmut sold the first wool shorn from Dolly to raise money for the care and treatment of kids with CF.
There are five potential uses for cloning humans or human cells: (1) a research tool to understand how genes in cells can be switched off and on; (2) growing new skin for burn victims; (3) culturing bone marrow that could be used to treat cancer patients; (4) manipulating genes to cure sickle cell anemia; (5) potential application in treating infertility.
A more controversial benefit is to provide children for lesbian couples. Normally they need an outsider to donate sperm; with cloning they would be able to avoid this.
Disadvantages:

There are several disadvantages associated with cloning, such as significant scientific uncertainty, medical risks, potential effects of aging, somatic mutation, and improper imprinting. A cloned child is not really a couple’s genetic child, but the child of only one of them. That imbalance may produce strains on the marriage the child might suffer identity confusion, and there is a risk of perpetuating the cause of sterility.Reproductive cloning is expensive and highly inefficient. More than 90% of cloning attempts fail to produce viable offspring. More than 100 nuclear transfer procedures could be required to produce one viable clone. In addition to low success rates, cloned animals tend to have more compromised immune function and higher rates of infection, tumor growth, and other disorders. Japanese studies have shown that cloned mice live in poor health and die early. About a third of the cloned calves born alive have died young, and many of them were abnormally large. Many cloned animals have not lived long enough to generate good data about how clones age. Appearing healthy at a young age unfortunately is not a good indicator of long term survival. Clones have been known to die mysteriously. For example, Australia's first cloned sheep appeared healthy and energetic on the day she died, and the results from her autopsy failed to determine a cause of death.
In 2002, researchers at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, reported that the genomes of cloned mice are compromised. In analyzing more than 10,000 liver and placenta cells of cloned mice, they discovered that about 4% of genes function abnormally. The abnormalities do not arise from mutations in the genes but from changes in the normal activation or expression of certain genes.
Problems also may result from programming errors in the genetic material from a donor cell. When an embryo is created from the union of a sperm and an egg, the embryo receives copies of most genes from both parents. A process called "imprinting" chemically marks the DNA from the mother and father so that only one copy of a gene (either the maternal or paternal gene) is turned on. Defects in the genetic imprint of DNA from a single donor cell may lead to some of the developmental abnormalities of cloned embryos.
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