Transgenic animals

2. SEMINAR ON
TRANSGENIC ANIMAL
Speaker:
Ananda Kumar Saha
Department of Zoology, R.U.

3. What is transgenic animal?
A transgenic animal is an animal that has been
genetically engineered to contain one or more extra
genes in its cell. It now has a new, inheritable
property of some type.

4. Genetically Modified Organisms
Genetically modified organisms are organisms
with artificially altered DNA.
Created By:
Adding a foreign gene
Altering the base sequence of an existing gene
Deleting or “ Turning off ” an existing gene

5. Adding a Foreign Gene
 Insect resistant plant
 Bioremediation
 Production of Insulin
 Vaccine (HBsAg)
 Herbicide resistant plant

6. Altering an Existing Gene
Existing genes in the organism are altered to make
it produce at higher levels (Growth hormone).
Deleting/Turning off an Existing Gene
Deactivating the gene responsible for the ripening
of tomatoes. This new gene can then be inserted
into tomato DNA to give them a longer shelf life.

7. Genetically Modified Animal
 Microinjection
 Embryonic stem cell transfer
 Nuclear Transfer

8. Microinjection
 Eggs are harvested from super-ovulated animals and
fertilized in vitro.
 Two hundred to three hundred copies of the foreign
gene are injected into the recently fertilized egg.
 Implanted into surrogate mothers.
 A small proportion of the animals born are transgenic.

9. MICROINJECTION PROCESS

10. Embryonic stem cell transfer
 Target gene sequences to specific sites in the
genome
 Alternations made to stem cells in culture
 Mutated stem cells injected into blastocyst
 Blastocyst implanted into foster mother
 Transgenic animals are born

11. Embryonic Stem Cell
Four Cell Stage
Two Cell Stage
Eight Cell Stage
Early Fertilization stage

12. Embryonic Stem Cell
Blastocyst Fetus (Pluripotent)
Adult

15. Nuclear Transfer
 Removing the nucleus of an unfertilized egg and replacing it with
the nucleus of a donar cell (hence containing the complete
genome)
 An electric current is used to fuse the nucleus in the cell and
trigger the egg to begin developing
 The reconstructed eggs are then implanted into a surrogate
mother.
 Somatic cells can be cultured, subjected to genetic manipulation
in vitro and then produce viable animals by means of nuclear
transfer.

18. “DOLLY” AND THE TRANSGENIC CLONES
Dolly was born in July 1996 and was introduced in
March 1997.
Wilmut and Cambell fused 277 adult mammary gland
cells with 277 egg cells, but they achieved only
thirteen pregnancies, and only one pregnancy
resulted in a live birth. But that one offspring, Dolly.

19. Scientist and Dolly
A B
A)Ian Wilmut, the Roslin Institute Researcher
B) Dolly, the cloned sheep who had a mother, but no father

20. TRANSGENIC ANIMAL PRODUCTS
Human Lactoferrin in Cow’s milk.
Lactoferrin a protein found in animal milk that has the
ability to bind iron molecule.
The protein has strong antibacterial properties because
it removes iron from the environment that bacteria need
for growth .It relieves iron-deficiency anemia.

21. Transgenic Goat
Milk contains protein normally found on the
surface of the parasite that causes malaria. The
protein elicit an antibody response in test
animals and could conceivably be used to
immunize against malaria.

22. HUMAN HEMOGLOBIN FROM PIG
Transgenic pig that produces human hemoglobin. Day
old embryos received injections of two genes for
hemoglobin production, and the embryos were then
implanted to surrogate.
Only about five in a thousand injections succeeded, and
only three pigs survived to birth .

23. Negative Side
 Nuclear transfer technology results in high mortalities
and low birth rates.
 The offspring are abnormally large size, undeveloped
lungs, ill health, implantation problem.
 Poor placental development are common.

24. Trangenic Animal
Cloned Kitten Cloned Pigs

25. Mule Endangered sheeps
Trangenic Animal

26. Do transgenic animals have any direct
benefit to humans?
DNA technologists have been able to produce a transgenic pig
that produces human hemoglobin. Purified hemoglobin from
this animal can one day be used in place of human blood for
transfusions during many surgical procedures.
QUESTIONLINE

27. Are there any other products possible from
transgenic animals?
Research work is currently progressing in methods to
obtain compounds that may be used to treat emphysemea,
cystic fibrosis, and dissolve blood clots.
QUESTIONLINE

28. How about improving the quality of the
animal itself?
 Transgenic cows, could one day produce a higher
quality milk, one that is similar to human milk.
 Chiken and cattle that synthesize antiviral proteins
encourage diseases resistance in their bodies. Such
animals, would require less antibiotic therapy.
QUESTIONLINE

29. 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.
 Higher rates of infection, tumour growth, and other
disorders.
 Australia’s first cloned sheep appeared healthy and
energetic on the day she died.

30. Should Humans be Cloned?
 Due to the inefficiency of animal cloning and
lack of understanding about reproductive
cloning, many scientist and physicians strongly
believe that it would be unethical to attempt to
clone humans.
 Several cloned animals have died prematurely
from infectious and other complications.
 The attempt to clone humans at this time is
considered potentially dangerous and ethically
irresponsible.

31. Thank you