Process of introducing a foreign or exogenous DNA into an animal genome is called as Transgenesis Transgenesis 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. Retroviruses used as vectors to transfer genetic material into the host cell Retroviruses can be used for the transfer of foreign genes into animal genomes. Embryonic stem cell-mediated gene transfer. Involves prior insertion of the desired DNA sequence by homologous recombination into an in vitro culture of embryonic stem (ES) cells. Incorporated into an embryo at the blastocyst stage of development.

1. TRANSGENIC
ANIMALS
UNDER THE GUIDANCE OF
Dr. Anjali Raj(Asst prof)
Dept of Pharmacology
BY
Monisha. K.C
Dept of pharmacology
The Oxford College of Pharmacy

2. TRANSGENESIS
Process of introducing a foreign or exogenous DNA
into an animal genome is called as Transgenesis
Transgenesis 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.

3. Need of
Transgenic
Animals
To study normal physiology
To study diseases models
Biological products
Xeno-transplanters
Transgenic food sourses

4. History
Father of transgenesis:- RALPH BRINSTER
First transgenic animal was a ‘Supermouse’ created by Ralph Brinster (U Pennsylvania) and
Richard Palmiter (University of Washington) in 1982. It was created by inserting a human
growth hormone gene in mouse genome. The offspring was much larger than the parents
DNA microinjection, the first technique to prove successful in mammals, was first applied
to mice (Gordon and Ruddle, 1981) and then to various other species such as rats, rabbits,
sheep, pigs, birds, and fish
Jaenisch, 1976—retrovirus-mediated transgenesis Gossler
1986—embryonic stem (ES) cell-mediated gene transfer
2007,Mario Ramberg Capecchi awarded Nobel Prize in Physiology or Medicine for
discovering a method to create mice in which a specific gene is turned off, known
as knockout mice

5. Examples of
transgenic animals
• Mouse
• Sheep
• Rabbit
• Cow
• Fish
• Horse
• Pigs
• Dogs

6. Transgenic fish
Superfish Increased growth and size
Growth hormone gene inserted into fertilized
egg.
Transgenic salmon grows about 10 – 11 times
faster than normal fish.
Glo fish freshwater zebra fish (Danio rerio)
Produced by inserting a fluorescent protein
gene from jelly fish into embryo of fish.

7. Transgenic sheep -Dolly
• Dolly born 5 July 1996
Roslin Institute, the
Scottish, and six months
later in February 1997, this
event shocked the whole
world - Dolly was cloned
from breast cells 6-year-old
adult sheep by transferring
the nucleus of the cell.
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9. Mule
A mule is the offspring
of a male Donkey(Jack)
and a female Horse.
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10. The Methodology
• STEP:-1
Construction of transgene
1. Promoter
2. Gene to be expressed
3. Termination sequence

11. STEP:-2
Introduction of foreign gene into the animal
STEP:-3
Screening for transgenic positives- screened by PCR to
examine the site of incorporation of the gene
STEP:-4
Further animal breeding is done to obtain maximal
expressions.

12. PRODUCTION
Microinjection method
Embryonic stem cell
method
Retro virus mediated
gene transfer method

13. 1. MICROINJECTION/ PRONUCLEAR MICROINJECTION
• A female animal is superovulated and eggs are collected.
• The eggs are fertilized in vitro.
• The transgene containing solution is injected into the male
pronucleus using a micropipette.
• Eggs with the transgenes are kept overnight in an incubator
to develop to a 2 cell stage.
• The eggs are then implanted into the uterus of a pseudo -
pregnant female (female which has been mated with a
vasectimized male the previous night)

16. 2. EMBRYONIC STEM CELL METHOD
• Embryonic stem cell-mediated gene transfer.
• Involves prior insertion of the desired DNA sequence by
homologous recombination into an in vitro culture of
embryonic stem (ES) cells. Incorporated into an embryo
at the blastocyst stage of development. • The result is a
chimeric animal.
• The method of choice for gene inactivation, the so-
called knock-out method.

18. 3. RETRO VIRUS MEDIATED GENE TRANSFER METHOD
• Retroviruses used as vectors to transfer genetic material into the
host cell
• Retroviruses can be used for the transfer of foreign genes into
animal genomes.
• This can best be done at 4-16 cell stage embryos.
• Completion of this process requires that the host cell undergoes the
S phase of the cell cycle. Therefore, retroviruses effectively
transduce only mitotically active cells.
• Very high rates of gene transfer are achieved with the use of
retroviruses

20. Maintenance of Transgenic Animals
• Housing
• feeding
• ventilation and lighting
• sanitation
• special care has to be taken with transgenic/gene knockout
animals
• the animals can be susceptible to diseases due to altered
metabolic activities.
• The transgenic and knockout animals should be maintained in
clean room environment or in animal isolations.

21. Recent
research
Transgenic goats engineered to produce
human breast milk.
• University of California scientists created the
transgenic goats by transferring human
genes for breast milk enzymes and proteins
into goat embryos.
• Produce 60% of the lysozyme and lactoferrin
found in human mother’s milk.
• For babies of mother’s who aren’t present or
can’t nurse them, milk from these transgenic
goats could provide the next best
alternative.

23. Application of transgenic animals In agricultural
application:
1. Selective breeding applied to get desired traits i.e high milk production and high
growth rate.
2. Traditional breeding is a time-consuming, difficult task.
3. Researchers have now used gene transfer to improve the productivity of
livestock.
4. Transgenic cows exist that produce more milk or milk with less lactose or
cholesterol. Transgenic cows have been used to produce milk which are richer in
proteins and lower in fat.

24. •Quality Herman, a transgenic
bull carries a human gene for
Lactoferrin (gene responsible for
higher iron content)
• Pigs and cattle that have more
meat on them. Sheep that grow
more wool.

25. Application
of transgenic
animals
Medical
Applications:
1. Transplant organ may comes from transgenic animals.
2. Transgenic pigs may provide the transplant organs needed
to alleviate the shortfall.
3. Currently, xenotransplantation is hampered by a pig protein
that can cause donor rejection but research is underway to
remove the pig protein and replace it with a human protein.
4. Products such as insulin, growth hormone, and blood anti-
clotting factors have already been obtained from the milk of
transgenic cows, sheep, or goats .
5. Finland produced a calf with a gene that makes the
substance that promotes the growth of red cells in humans

27. Limitations of Transgenic animals
Inserted gene has multiple function
Breeding problem
Sometimes leads to mutagenesis and functional disorder
Low survival rate of transgenic animal