8071790.ppt
- 2. Introduction Cloning- the process of making an identical organism through nonsexual means In 1997 Ian Wilmut at the Roslin Institute in Edinburgh, Scotland successfully clone the first mammal, a sheep name Dolly In January 2001 scientist Panayiotis Zavos and researcher Severino Antinori said that they are planned to clone a human in the next two years.
- 3. Are there different types of cloning? The following three types of cloning technologies will be discussed: (1) recombinant DNA technology or DNA cloning (2) reproductive cloning (3) therapeutic cloning.
- 4. Recombinant DNA Technology or DNA Cloning The terms "recombinant DNA technology," "DNA cloning," "molecular cloning,"or "gene cloning" all refer to the same process: the transfer of a DNA fragment of interest from one organism to a self-replicating genetic element such as a bacterial plasmid. The DNA of interest can then be propagated in a foreign host cell. This technology has been around since the 1970s, and it has become a common practice in molecular biology labs today.
- 5. Plasmids Scientists studying a particular gene often use bacterial plasmids to generate multiple copies of the same gene. Plasmids are self-replicating extra-chromosomal circular DNA molecules
- 7. Clone a gene To "clone a gene," a DNA fragment containing the gene of interest is isolated from chromosomal DNA using restriction enzymes and then united with a plasmid that has been cut with the same restriction enzymes. When the fragment of chromosomal DNA is joined with its cloning vector in the lab, it is called a "recombinant DNA molecule." Following introduction into suitable host cells, the recombinant DNA can then be reproduced along with the host cell DNA
- 8. Reproductive Cloning Reproductive cloning is a technology used to generate an animal that has the same nuclear DNA as another currently or previously existing animal In a process called "somatic cell nuclear transfer" (SCNT), scientists transfer genetic material from the nucleus of a donor adult cell to an egg whose nucleus, and thus its genetic material, has been removed. The reconstructed egg containing the DNA from a donor cell must be treated with chemicals or electric current in order to stimulate cell division. Once the cloned embryo reaches a suitable stage, it is transferred to the uterus of a female host where it continues to develop until birth.
- 9. Human Cloning Somatic cell nuclear transfer Human repair kit, they can grow organs such as hearts, livers, and skins. They can also be used to grow neurons to cure those who suffer from Alzheimer's, Parkinson's.
- 10. Therapeutic Cloning Therapeutic cloning, also called "embryo cloning," is the production of human embryos for use in research. The goal of this process is not to create cloned human beings, but rather to harvest stem cells that can be used to study human development and to treat disease. Stem cells are important to biomedical researchers because they can be used to generate virtually any type of specialized cell in the human body Many researchers hope that one day stem cells can be used to serve as replacement cells to treat disease
- 11. 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. 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.
- 12. More Cloning technologies 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. 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
- 13. What animals have been cloned? Hundreds of cloned animals exist today, but the number of different species is limited. Attempts at cloning certain species such as monkeys, chickens, horses, and dogs, have been unsuccessful. Some species may be more resistant to somatic cell nuclear transfer than others. The process of stripping the nucleus from an egg cell and replacing it with the nucleus of a donor cell is a traumatic one, and improvements in cloning technologies may be needed before many species can be cloned successfully.
- 14. Organ Transplantation Thousands of people die every year waiting for a transplant Cloning technology could someday be used to produce whole organs. Embryonic stem cells also have the potential for use in the production of tissues. www.tufts-nemc.org www.c-science.com
- 15. What are the risks of cloning? 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. Many cloned animals have not lived long enough to generate good data about how clones age. 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.
- 16. Bottom Line We still have A LOT to learn about DNA and the genetic code As genetic engineers we have much to understand and we are still in the infancy of our understanding of our own genetic code. As we learn and understand more genetic engineering will be a part of every day life. We’ve made great leaps in a very short time since the discovery of DNA but we still have a long way to go. . . . .