1. 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.
3. 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, plasmi
d vectors, viral
vectors, pronuclear
injection, protoplast fusion,
and ballistic DNA injection.
4. Transgenic organism
It is defined as living
organisms containing
genetic material into
which DNA from a
different organism has
been artificially
introduced.
5. 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
6. 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.
7. 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.
8. METHODS OF TRANGENESIS
There are three basic methods of transgenesis:
1. DNA microinjection
2. Retrovirus – mediated gene transfer
3. Embryonic stem cell – mediated gene transfer
9. 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.
10. 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.
11. 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.
13. Inserted gene has multiple function.
Breeding problems.
Some time leads to mutagenesis and
functional disorder.
Low survival rate of transgenic animals.
DISADVANTAGES
15. 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)
16. 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 21st 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.