Biology Project

Animal Cloning

Content

• 1.Introduction

• 2.Technology and Processing

• 3.Triggered Problems

• 4.PROs and CONs

• 5.Prospects

• 6.Conclusion

Introduction

• Cloning of a more limited sort has been done for years -

researchers have already cloned mice, frogs, and sheep with cells taken from embryos. The success of cloning Dolly, the 1st mammal to be cloned from a mature ewe, makes a stunning breakthrough. Since then, this reality of animal cloning stares us in the face and human cloning around the corner. Proponents of human cloning assists that this technology can lead medical science into a new epoch. However, many problems are also raised, such as moral and ethical arguments. Some protests afraid that cloning of human may damage the human species as well.

How Dolly was created

Nuclear Transfer Technology

• 1.Nuclear transfer involves transferring the complete genetic material (the DNA contained in a nucleus) from one cell into an unfertilised egg cell whose own nucleus has been removed.

• 2.A technique known as twinning exists, but can only be used before an organism’s cells differentiate. All cloning experiments of adults mammals have used a variation of

nuclear transfer.

• 3.Nuclear transfer requires two cells, a donor cell and an oocyte, or egg cell.First, the donor cells are grown under special conditions in culture. In this way the number of cells can be increased by several orders of magnitude. It is also possible to make genetic modifications and to select just those cells in which the desired modification has occurred and multiply these up.

• 4.Research has proven that the egg cell works best if it is unfertilized, because it is more likely to accept the donor nuclear as its own. The egg cell must be enucleated. This eliminates the majority of its genetic information.

• 5.The donor cell is then forced into the Gap Zero, or GO cell stage, a dormant phase, different ways depending on the technique. This dormant phase causes the cell to shut down but not die. In this state, the nucleus is ready to be accepted by the egg cell.

• 6.The donor cell’s nucleus is then placed inside the egg cell, either through cell fusion or transplantion. The egg cell is then prompted to begin forming an embryo. When this happens, the embryo is then transplanted into a surrogate mother. If all is done correctly, occasionally a perfect replica of the donor

animal will be born naturally.

• Method of Nuclear Transfer in Livestock

Remarks of Nuclear transfer Technology

• 1. This technology could allow the production of genetically identical groups of animals which possess a desirable genetic trait.

• 2. The work to date has shown the technology to be successful only in sheep.

• 3. PPL Therapeutics hopes to use this technique to enable the production of new drugs for the treatment of a range of conditions using its transgenic technology. This could lead to cheaper drugs for currently untreatable diseases.

Triggered Problems

• Cloning may trigger some problems:• In fact,the adult female ewe is both the genetic mother and the genetic

father of Dolly.And the female from whom the egg came and the female who gestated Dolly and gave birth to her are two more maternal to her.Which of these we would even call the parent to

Dolly?Also,if you’re cloning someone to replace a child who died,then you might love the new child especially dearly.But the new child might not particularly like the fact that was the reason it was born.

• Creating animals with genetic defects also raises challenging ethical questions

• Cloning would further violate human dignity by denying the intrinsic value of each human life,thereby viewing human being as commodities oppose surrogate parenting contracts,genetic screening of embryos before uterine implanting and sex selection abortion.Because a cloned person will not be created simply for their value as a person.

PROs• It seems clear that cloning from cultured cells will offer important

medical opportunities.For example,to help to produce discoveries that will effect the study of genetics, cell development, human growth, and obstetrics.The advantages of cloning animals are displayed here.

• 1.Producing a greater understanding of the cause of miscarriages

• Cloning may lead to a treatment to prevent spontaneous abortions-help women who can't bring a fetus to term. Also, It might lead to an understanding of the way a morula (mass of cells developed from a blastula) attaches itself to the uterine wall. This might generate new and successful contraceptives.

• 2.Generation of genetically modified animal organs• Cloning can generate genetically modified animal organs that are

suitable for transplantation into humans.At present,thousands of patients die every year before a replacement heart,liver or kidney becomes available.A normal pig organ would be rapidly destroyed by a “hyperacute” immune reaction if transplanted into a human.This reaction is triggered by proteins on the pig cell that have been modified by an enzyme.

• 3. Preventing child suffering heredity• Cloning could also be used for parents who risk passing a defect to a

child. A fertilized ovum could be cloned, and the duplicate tested for disease and disorder.This could help the child to prevent suffering heredity.

• 4.Cure damaged nervous system• Damage to the nervous system could be treated through cloning.

Damaged adult nerve tissue does not regenerate on its own. However, stem cells might be able to repair the damaged tissue.Human can help to produce large number of cells.

CONs• To those against it,cloning presents as much a moral problem as a

technical problem.Cloning is an affront to religious sensibilities,and interfering with the natural process. There are objections, regarding susceptibility to decrease,expense,and diversity.Their basic disadvantages to cloning research are as follows:

• 1.Reducing genetic variability• Producing many clones runs the risk of creating a population that is

entirely the same, susceptible to the same diseases, and one disease could devastate the entire population.There are more probable events could occur from a lack of genetic diversity.

• 2.Interfering with natural evolution• Cloning may cause people to settle for the best existing animals, not

allowing for improvement of the species. In this way, cloning could potentially interfere with natural evolution.

• 3.Risk of disease transfer• Risk of disease transfer between transgenic animals and the animal

from which the transgenes were derived.e.g. If an animal producing drugs in its milk becomes infected by a virus, the animal may transmit

the virus to a patient using the drug.• 4.Genetic tailoring of offspring• The ability to clone humans may lead to the genetic tailoring of

offspring. It is conceivable that scientists could alter a baby's genetic code to give the individual a certain color of eyes or genetic resistance to certain diseases. This is viewed as inappropriate tampering with "Mother Nature" by many ethicists.

• 5.Detrimental effect on familial relationships• A child born from an adult DNA cloning of his father could be

considered a delayed identical twin of one of his parents. It is unknown as to how a human might react if he or she knew he or she

was an exact duplicate of an older individual.

The future of Cloning• 1.Contributing the biomedical and pharmaceutics.• Through nuclear transfer,bio medical research and pharmaceutics, medicine and

hormones can be produced. If human genes are introduced into other organisms, like pigs and sheep, these transgenic animals can produce human proteins. Animals can be used as "drug factories," producing human proteins and producing insulin,used to treat diabetes.Transgenic sheep can produce a drug that is used to treat cystic fibrosis.

• 2.Contributing to disease treatment• Cloning research may contribute to disease treatment,for example,skin cells

could be reprogrammed into the insulin producing cells in the pancreas. These skin cells would then be introduced into the pancreas of a diabetes patient, allowing them to produce insulin. Parkinson's Disease is a degenerative disease affecting neurons. Cloning research could allow the reprogramming of cells into neurons to replace those damaged by Parkinson's.

• 3.Contributing to organ transplantation• Through cloning, organ transplantation may become a more successful

process. Although organ transplantation is a common occurrence, there is often a shortage of organs suitable for transplantation. Xenotransplantation, transplanting organs from one species to another, provides a solution to organ shortage. From future cloning research, human organs may be cultured from outside the body. In the future, humans might be able to clone their own organs for personal transplantation.

• 4.Contributing to create a clone from the dead to duplicate extinct animals

• If they’ve been frozen or part of their tissues or blood has been frozen,then it might be possible to make a clone.It would be impossible to clone from an extinct animal because the whole nucleus will have disintegrated,losing all structure and causing all the DNA to degrade.

• 5.Contributing to the improvement of gene:

• At present,nobody know what the genes are that give us our individuality,our characteristics,the genes that are associated with higher intelligence.

Conclusion

• In 21st century, genetic engineering is very important as well as information technology. Cloning seems set to become a vital technology for agriculture and medicine. We should point out that ,with the careful continuation of research, the technological benefits of cloning clearly outweigh the possible social consequences. In their minds, final products of cloning, like farm animals, and laboratory mice will not be the most important achievement. The applications of cloning they envision are not nightmarish and inhumane, but will improve the overall quality of science and life.

Member List

• Yip Ka Lai(Jocelyn)7B

• Ng Ka Ying(Christy)7A

• Yik Nga Che(GiGi)7B

• Chiu Chi Kit(Teddy)7B

Reference

• Http://sciam.com/1998/1298issue/1298wilmut.html• Http://www.pathfinder.com/TIME/cloning• Http://www.sciam.com/explorations/090297clone/

beardslep.html• Http://www.newscientist.com/nsplus/insight/

clone/growyour.html• Http://www.geocities.com/ResearchTriangle/Lab/

2705/speech.html