Cloning

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Cloning

  1. 1. • Cloning describes a number of different processes that can be used to produce genetically identical copies of a biological entity. • Clones are organisms that are exact genetic copies. Every single bit of their DNA is identical. • Human Identical Twins are clones of each other.
  2. 2. • Collectively refers to processes used to create copies of DNA fragments. • Animal cloning has been the su-bject of scientific experiments for years, but garnered little attention until the birth of the first cloned mammal in 1996, a sheep named Dolly.
  3. 3. • Since Dolly, several scientists have cloned other animals, including cows and mice. • No human cloning attempts have been made because there have been many disadvantages that involve the cloning of both humans and animals.
  4. 4. HISTORY OF CLONING
  5. 5. TYPES OF CLONING
  6. 6. CLONING Artificial Embryo Twinning Reproductive cloning THERAPUETIC CLONING Natural Cloning
  7. 7. NATURAL CLONING
  8. 8. • Natural Cloning • In nature, twins form very early in development when the embryo splits in two. Twinning happens in the first days after egg and sperm join, while the embryo is made of just a small number of unspecialized cells. Each half of the embryo continues dividing on its own, ultimately developing into separate, complete individuals. Since they developed from the same fertilized egg, the resulting individuals are genetically identical.
  9. 9. • Artificial Embryo Twinning • Artificial embryo twinning is a relatively low-tech way to make clones. As the name suggests, this technique mimics the natural process that creates identical twins. • Artificial embryo twinning uses the same approach, but it is carried out in a Petri dish instead of inside the mother. A very early embryo is separated into individual cells, which are allowed to divide and develop for a short time in the Petri dish. The embryos are then placed into a surrogate mother, where they finish developing. Again, since all the embryos came from the same fertilized egg, they are genetically identical.
  10. 10. REPRODUCTIVE CLONING
  11. 11. CLONING Artificial Embryo Twinning Reproductive cloning THERAPUETIC CLONING Natural Cloning
  12. 12. • Reproductive cloning • Somatic Cell Nuclear Transfer • Somatic cell nuclear transfer (SCNT), also called nuclear transfer, uses a different approach than artificial embryo twinning, but it produces the same result: an exact genetic copy, or clone, of an individual. This was the method used to create Dolly the Sheep.
  13. 13. • What does SCNT mean? Let's take it apart • Somatic cell • A somatic cell is any cell in the body other than sperm and egg, the two types of reproductive cells. Reproductive cells are also called germ cells. In mammals, every somatic cell has two complete sets of chromosomes, whereas the germ cells have only one complete set.
  14. 14. • Nuclear: • The nucleus is a compartment that holds the cell's DNA. The DNA is divided into packages called chromosomes, and it contains all the information needed to form an organism. It's small differences in our DNA that make each of us unique. • Transfer: • Isolate a somatic cell from an adult female Next they remove the nucleus and all of its DNA from an egg cell. Then we transfer the nucleus from the somatic cell to the egg cell. After a couple of chemical tweaks, the egg cell, with its new nucleus, will behave just like a freshly fertilized egg. It is developed into an embryo, which was implanted into a surrogate mother and carried to term.
  15. 15. • THERAPUETIC CLONING • you may have heard about researchers cloning, or identifying, genes that are responsible for various medical conditions or traits. What's the difference? • When scientists clone an organism, they are making an exact genetic copy of the whole organism. • When scientists clone a gene, they isolate and make exact copies of just one of an organism's genes. Cloning a gene usually involves copying the DNA sequence of that gene into a smaller, more easily manipulated piece of DNA, such as a plasmid. This process makes it easier to study the function of the individual gene in the laboratory.
  16. 16. • There will be an endless supply of animals to clone, and we will never run out of food from animals. • The animal in which we intend to clone will result perfectly the same as the animal which has been cloned in every way, the eyes, the nose, the ears, the face, everything provided the environment is same.
  17. 17. • Chance of curing certain diseases and being able to breed ideal stock for research and consumption. • Cloning a extinct species to bring them back, to clone organs to repair damaged organs in people, and variety of other medical advancements
  18. 18. DISADVANTAGES OF CLONING
  19. 19. • Disadvantages of cloning is the cost, the technology being used for less than honorable ways, and the controversy that surrounds cloning. • Losing gene diversity is another of the disadvantages of cloning. DISADVANTAGES OF CLONING
  20. 20. • Another of the disadvantages of cloning is that there are a lot of ethical considerations that would cause most people to protest. One of these ethical concerns is that cloning is unnatural, and considered “playing GOD.” • Because of the risk taking involved in cloning, it is a technology that many experts say may be better left alone, at least until it is better understood. DISADVANTAGES OF CLONING
  21. 21. • United Kingdom: • On January 14, 2001 the British government passed The Human Fertilisation and Embryology (Research Purposes) • Regulations 2001 to amend the Human Fertilisation and Embryology Act by permitting to research around • stem cells and cell nuclear replacment,thus allowing therapeutic cloning. LEGAL ISSUES
  22. 22. • United Nations: • On December 13, 2001, the United Nations General Assembly began elaborating an international convention against the reproductive cloning of humans,A broad coalition of States, including Spain, Italy, the Philippines, the United States, Costa Rica and the Holy See sought to extend the debate to ban all forms of human cloning, noting that, in their view, therapeutic human cloning violates human dignity. • In March 2005 a non-binding United Nations Declaration on Human Cloning, calling for the ban of all forms of Human Cloning contrary to human dignity, was adopted. LEGAL ISSUES
  23. 23. • United States • In 1998, 2001, 2004 and 2007, the United States House of Representatives voted whether to ban all human cloning, both reproductive and therapeutic. • On March 10, 2010 a bill was introduced with a section banning federal funding for human cloning. • Such a law, if passed would not prevent research from occurring in private institutions (such as universities) that have both private and federal funding. • There are currently no federal laws in the United States which ban cloning completely, and any such laws would raise difficult Constitutional questions similar to the issues raised by abortion. LEGAL ISSUES
  24. 24. • INDIA • The Department of Biotechnology of the Ministry of Science and Technology has adopted ethical policies on the human genome, • which have laid down inter alia India’s position on cloning. The text, “Ethical Policies on the Human Genome, • Genetic Research and Services,” states that, “as a principle, human cloning shall not be permitted.” LEGAL ISSUES
  25. 25. CASE STUDIES
  26. 26. • Lenon’s Tooth: • Here is a story for your "truth is stranger than fiction" files: a Canadian dentist paid approximately $31,000 in 2011 for a tooth extracted from the late John Lennon. Dr. Michael Zuk recently announced that he has sent the tooth to a U.S. laboratory in hopes of having DNA extracted and sequenced. His ultimate goal is to have John Lennon cloned. Dr.Zuk has outlined his plans on a website. • It is unclear whether any DNA that is of sufficient quality for sequencing remains in the tooth. The tooth was rotten when it was removed in the 1960s. Lennon gave the tooth to his housekeeper at the time, and her son eventually put it up for auction. • The media has covered the story as an amusing piece of news. However, the articles have failed to cover the two main ethical issues raised by the story. Firstly, is John Lennon's privacy (and the privacy of his descendants), violated by the DNA sequencing effort? • The first ethical reason would be that John Lennon's two sons share his genetic information and would potentially be affected if the sequence is ever released publically. CASE STUDIES 1
  27. 27. • Lenon’s Tooth • The second ethical concern raised by Dr.Zuk's efforts is whether human cloning is acceptable. Based on his statements, Dr.Zuk has undertaken this project in hopes of "bringing back" a musical legend that died tragically before his time. To be clear, if John Lennon were successfully cloned, the new John Lennon would NOT be the same man we are all familiar with. The clone would share DNA with the original but would not share any of the life experiences that shaped his persona. Many human traits, both physical and behavioral, are influenced to varying degrees by the environment. As a comparison, identical twins are genetic clones but typically differ in appearance, behavior, and the diseases that affect them. This is particularly apparent in older twins after years of different environmental influences. • You may be surprised that the U.S. does NOT have any federal laws banning human cloning!! YAY! We might just have another John-the-legend-wait-for-it-dary-lenon ;) :D CASE STUDIES 1
  28. 28. • DOLLY THE SHEEP • Dolly the sheep, as the first mammal to be cloned from an adult cell, is by far the world's most famous cloneIn 1996, cloning was revolutionized when Ian Wilmut and his colleagues at the Roslin- Institute in Edinburgh, Scotland. • To produce Dolly, scientists used an mammary gland cell from a six-year-old Finn Dorset white sheep. They had to find a way to 'reprogram' the mammary 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 research team 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. CASE STUDIES 2
  29. 29. • DOLLY THE SHEEP • 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 6.6 kg Finn Dorset lamb 6LLS (alias Dolly) was born after 148 days. CASE STUDIES 2
  30. 30. • What happened to Dolly? • Dolly 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 that is common among sheep which are raised indoors. • The DNA in the nucleus is wrapped up into chromosomes, which shorten each time the cell replicates. This meant that Dolly’s chromosomes were a little shorter than those of other sheep her age and her early ageing may reflect that she was raised from the nucleus of a 6-year old sheep. Dolly was also not entirely identical to her genetic mother because the mitochondria, were inherited from Dolly’s egg donor mother. CASE STUDIES 2
  31. 31. • Why clone sheep? • Dolly the sheep was produced at the Roslin Institute as part of research into producing medicines in the milk of farm 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. CASE STUDIES 2
  32. 32. • Since Dolly • Since 1996, when Dolly was born, other sheep have been cloned from adult cells, as have cats, 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. • Improvements in the technique have meant that the cloning of animals is becoming cheaper and more reliable. • The advances made through cloning animals have led to a potential new therapy to prevent mitochondrial diseases in humans being passed from mother to child. About 1 in 6000 people is born with faulty mitochondria, which can result in diseases like muscular dystrophy. To prevent this, genetic material from the embryo is extracted and placed in an egg cell donated by another woman, which contains functioning mitochondria. This is the same process as used in cloning of embryonic cells of animals. CASE STUDIES 2
  33. 33. • JUST IMAGINE !! • Human cloning technology could be used to reverse heart attacks. Scientists believe that they may be able to treat heart attack victims by cloning their healthy heart cells and injecting them into the areas of the heart that have been damaged. • Infertility - infertile couples can have children • Down's syndrome - those women at high risk for Down's syndrome can avoid that risk by cloning • Leukemia - we should be able to clone the bone marrow for children and adults suffering from leukemia. This is expected to be one of the first benefits to come from cloning technology. • Cancer - we may learn how to switch cells on and off through cloning and thus be able to cure cancer Potential Benefits of Human Cloning
  34. 34. • Do you approve of human cloning ? • Do you approve cloning of other animals ? • Do you think it’s right to harvest organs and tissue from clones ? • If you had the option,would you want to clone yourself ? Why ? • Do you think the benefits outweigh the risks with cloning humans ?

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