2. DEFINITION
• Carries a foreign gene that has been
deliberately inserted into its genome
• Foreign gene is constructed using recombinant
DNA technology
3. WHY CREATE THEM?
• Improve livestock animals
• Use of animals as bioreactors
• Production of pharmaceutical drugs
• Used as Model Organisms in research
4. CREATION PRINCIPLE
• Inserting a foreign gene/genes into an animal
• The inserted genes are called Transgenes
• Genes must be transmitted through the germ
line
8. 1. DNA Microinjection
2. Retrovirus-Mediated Gene Transfer
3. Embryonic Stem Cell-Mediated Gene
Transfer
4. Linker Based Sperm-Mediated Gene
Transfer
There are 4 basic methods:
9. 1) DNA Microinjection
• Eggs are harvested from the animal
• Transfer the desired gene into the pronucleus of the
sperm
• Egg is then fertilized invitro & cultured to develop
embryonic phase
• Transferred to the recipient female
10.
11. 2) Retrovirus-Mediated Gene Transfer
• A retrovirus is an animal virus that contain RNA
that encodes for DNA.
• Retroviruses transfer genetic material into the
host cell to produce Chimeras- animal with
mixed DNA
• Chimeras are inbred until homozygous transgenic
offspring are born
12. Vector binds
to cell
membrane
Vector packaged
In vesicle
Vesicle breaks down
Releasing vector
Vector injects new
Gene into nucleus
Modified DNA injected
Into vector
Cell makes protien
using new gene
Viral
DNA
Viral
DNA
New
gene
13. 3) Embryonic Stem Cell
Method
• Desired genes are inserted into the totipotent
stem cells
• Cells transform to express the desired gene is
selected & injected into the inner cell mass of
the organism blastocyst
• Embriyo is then implanted into foster mother
• Multiple matings within generations is done to
get a homozygous offspring
14. Alterations made to
Stem cells in culture
Fertilised egg
blastocyst
Blastocyst implanted into
Foster mother
Mutated
Stem cells
Injected
Into
blastocyst
15. 4) Linker Based Sperm-Mediated
Gene Transfer
• Sperm carrying the foreign gene, fertilizes the
egg where foreign gene is incorporated into
the genome
16. STEP 3
Screening for transgenic
positives
• Transgenic progenies are screened by
PCR to examine the site of incorporation
of the gene
17. STEP 4
Further animal breeding is
done to obtain maximal
expression
• Heterozygous offsprings are mated to
form homozygous strains.
19. Transgenic Cow
• Carry extra copies of two types of Casein genes
• 13% more milk protein
• Milk -more nutritious
• Currently the milk from these animals is under
FDA review
20. EnviroPig
• Can digest plant phosphorus more efficiently
• Have Phytase enzyme in their salivary glands
• Phytic acid in the pig meal is degraded releasing
phosphorus which is absorbed by the pig
• Pig waste is a major pollutant
Pig for organ transplant
– Pigs with human genes
– decrease the chance of organ
rejection by human body.
21. Transgenic Fish
• Salmon/trout- can grow up to
6 times faster than wild-type
fish as they have extra copies
of Growth Hormone (GH) gene
• Ornamental GloFish have red,
green, yellow, and orange fluorescent
color,available as a pet.
22. Transgenic Mice
• Most widely used
Model Animal to detect
gene expression
• Used in Knock-Out
technology to detect
gene function
23. GENE KNOCKOUT
• Technique for selectively inactivating a gene
by replacing it with a mutant allele
• Gene knockout mice are model systems for
studying inherited human diseases
24. • Alzheimer’s mouse
– Mouse made by introducing amyloid
precursor gene into fertilized egg of mice.
• Oncomouse
– Mouse model to study cancer
– Made by inserting activated oncogenes.
• Smart mouse
– Biological model engineered to overexpress NR2B
receptor in the synaptic pathway.
– This makes the mice learn faster like juveniles
throughout their lives.
25. Transgenic Monkey
• ANDI, the first transgenic
rhesus monkey born on
October 2nd 2000, has GFP
gene
• Glow in Dark Monkeys also
have GFP and glow under UV
light
• Model for studying
autism,Alzhiemers,MND etc
26. Transgenic Rabbit
• Alba, the EGFP (enhanced
GFP) bunny created in 2000
as a transgenic artwork
• Has GFP gene and glows
when exposed to Blue light
• Used as model for
cardiovascular
diseases,AIDS & cancer
• As bioreactors for human
protiens
28. Transgenic Goats
• Silk gene from
spiders is transferred
to goats
• Each goat produces
several grams of silk
protein in her milk
29. Some Ethical Concerns
• Use of animals in research causes great suffering to the
animals
• Using animals for the production of pharmaceutical
proteins will reduce them to mere factories
• Animals should have the same basic rights as human beings
• Each biological species has a right to exist as a separate
identifiable entity
• Animal model is not patentable in India
30. ISSUES RELATED TO TRANSGENIC
TECHNOLOGY
• Blurring the lines between species by creating
transgenic combinations.
• Health risks associated with transgenics.
• Long term effects on the environment when transgenic
animals are released into the field.
• Various bioethicist argue that it is wrong to create
animals that would suffer as a result of genetic
alteration.
31. IMPORTANCE OF TRANSGENIC
ANIMALS
• Medical importance
– Disease model
– Bioreactors for pharmaceuticals
– Xenotransplantation
• Agricultural importance
– Disease resistant animals
– For improving quality and quantity of milk, meat, eggs and wool
production
• Industrial importance
– Toxicity sensitive transgenic animals to test chemicals.
– Spider silk in milk of goat
33. NUDE MICE
• First discovered in 1962 by Dr. N. R. Grist
at Ruchill Hospital's Brownlee virology
laboratory in Glasgow
• laboratory mouse from a strain with a genetic
mutation
• Spontaneous deletion in the FOXN1 gene.
34. NUDE MICE
• Deteriorated or absent thymus
• Inhibited immune system due to a greatly
reduced number of T cells
• Phenotype-lack of body hair
35. Without the thymus gland ,these mice are
unable to
– Kill virus infected cells/malignant cells
– Reject tissue grafts, even xenografts
– Form Ab (dependent on T cells)
– Develop hypersensitivity responses
36. USES
1. Testing anticancer therapies for human
neoplasms
2. Study of leukaemias,solid tumours
3. Invivo study of metastasis
4. Provided an insight into the functioning of
immune system, T cell differentiation,specific
cellular reactions
5. Study of AIDS & other immunodeficiencies
6. Thermogenesis in imm. def. states
Notas do Editor
the poly(A) tail protects the mRNA molecule from enzymatic degradation in the cytoplasm and aids in transcription termination, export of the mRNA from the nucleus, and translation
pronucleus (plural: pronuclei) is the nucleus of a sperm or an egg cell during the process of fertilization, after the sperm enters the ovum, but before they fuse
A genetic chimerism or chimera (also spelled chimaera) is a single organism composed of cells from different zygotes.
technique that transfers genes based on the ability of sperm cells to spontaneously bind to and internalize exogenous DNA and transport it into an oocyte during fertilization to produce genetically modified animals. The exogenous DNA interacts with the DNA-binding proteins (DBPs) that are present on the surface of the sperm cell.inhibitory factor. Therefore, the seminal fluid must be removed from the sperm samples by extensive washing immediately after ejaculation.
AgResearch in New Zealand. therapeutic agents isolated from the milk of transgenic animals, C1 inhibitor (Ruconest) and antithrombin (ATryn),
green fluorescent protein (GFP). This GFP gene, which is naturally occurring in jellyfish, was taken from a jellyfish ANDi means inserted DNA
Researchers from the University of Wyoming have developed a way to incorporate spiders' silk-spinning genes into goats, allowing the researchers to harvest the silk protein from the goats’ milk for a variety of applications. For instance, due to its strength and elasticity, spider silk fiber could have several medical uses, such as for making artificial ligaments and tendons, for eye sutures, and for jaw repair. The silk could also have applications in bulletproof vests and improved car air