Transgenesis

process and methods

1. Transgenesis Chandresh Tripathi Introductry part and ethics. Km. Amita Singh Gene therapy and methods Madhav Tripathi conclusion Komal Verma Application of transgenesis . Deepa Yadav Pros. And Cons. Astha Yadav History

2. Introduction It is the process of introducing an exogenous gene—called a  transgene —into a living organism so that the organism will exhibit a new property and transmit that property to its offspring. Transgenesis can be facilitated by liposomes, enzymes, plasmid vectors, viral vectors, pronuclear injection, protoplast fusion, and ballistic DNA injection.

3. Transgenic organism It is defined as living organisms containing genetic material into which DNA from a different organism has been artificially introduced.

4. GMO’s Transgenic organisms have also been developed for commercial purposes. Perhaps the most famous examples are food crops like soy and corn that have been genetically modified for pest and herbicide resistance. These crops are widely known as “ GMOs ” (genetically modified organisms).  Few examples are- Golden rice transgene yeast edible vaccine in banana blue roses goat producing ATryn

5. GENE THERAPY Gene therapy is an experimental technique that uses genes to treat or prevent disease. In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or surgery. Researchers are testing several approaches to gene therapy, including: Replacing a mutated gene that causes disease with a healthy copy of the gene. Inactivating, or “knocking out”, a mutated gene that is functioning improperly. Introducing a new gene into the body to help fight a disease. Although gene therapy is a promising treatment option for a number of diseases (including inherited disorders, some types of cancer, and certain viral infections), the technique remains risky and is still under study to make sure that it will be safe and effective, gene therapy is currently being tested only for diseases that have no other cures.

6. DIFFERENCE BETWEEN TRANSGENESIS AND GENE THERAPY Somehow they are similar but not the same. Gene therapy is injecting a gene into an organism to make it make more of the gene product – so only the cells around the injection site are altered. A transgenic organism is one that is genetically altered before birth, so every cells has the altered copy of the gene.

7. METHODS OF TRANGENESIS There are three basic methods of transgenesis: DNA microinjection Retrovirus – mediated gene transfer Embryonic stem cell – mediated gene transfer

8. DNA MICROINJECTION The mouse was the first animal to undergo successful gene transfer using DNA microinjection. This method involves: Transfer of a desired gene construct (of a single gene or a combination of genes that are recombined and then cloned) from another member of the same species or from a different species into the pronucleus of a reproductive cell. The manipulated cell, which first must be cultured in vitro (in a lab, not in a live animal) to develop to a specific embryonic phase, is then transferred to the recipient female.

9. RETROVIRUS – MEDIATED GENE TRANSFER A retrovirus is a virus that carries its genetic material in the form of RNA rather than DNA. This method involves: Retroviruses used as vectors to transfer genetic material into the host cell, resulting in a chimera, an organism consisting of tissues or parts of diverse genetic constitution. Chimeras are inbred for as many as 20 generations until homozygous (carrying the desired transgene in every cell) transgenic offspring are born The method was successfully used in 1974 when a simian virus was inserted into mice embryos, resulting in mice carrying this DNA.

10. EMBRYONIC STEM CELL – MEDIATED GENE TRANSFER This method involves : Isolation of totipotent stem cells (stem cells that can develop into any type of specialized cell) from embryos . The desired gene is inserted into these cells. Cells containing the desired DNA are incorporated into the host’s embryo, resulting in a chimeric animal. Unlike the other two method, which require live transgenic offspring to test for the presence of the desired transgene, this method allows testing for transgenes at the cell stage.

11. Increased growth rate. Improved disease resistance. Improved food conversion rates. Increased muscle mass. Improved nutritional value. Improved wool quality. ADVANTAGES

12. Inserted gene has multiple function. Breeding problems. Some time leads to mutagenesis and functional disorder. Low survival rate of transgenic animals. DISADVANTAGES

13. Thank you

14. Ethics with transgenesis - Who will have access to these technologies and how will scarce resources—such as medical advances and novel treatments—be allocated ? What, if any, health risks are associated with transgenics and genetically modified foods ? Are species boundaries “hard” or should they be viewed as a continuum? What , if any, consequences are there of blurring species boundaries? (Source : http:// www.actionbioscience.org)

15. Conclusion It is the process of introducing an exogenous gene—called a  transgene —into a living organism so that the organism will exhibit a new property and transmit that property to its offspring. Transgenics continue to present intriguing and difficult challenges for 21 st century scientists and ethicists, and education and meaningful, respectful discourse are just the beginning of what is required to tackle such complex ethical issues. Until we as a society or, perhaps, as a global entity can agree on what beings—human or otherwise—are worthy of moral and legal status and respect, we can expect intense cross-disciplinary debate and discussion as new life forms are created through science and medicine . This is certainly a good turn of events since transgenic technology holds great potential in many fields, including agriculture, medicine, and industry.