2. What is transgenic animal?
The term transgenic animal refers to an animal in which
there has been a deliberate modification of the genome -
the material responsible for inherited characteristics - in
contrast to spontaneous mutation. Foreign DNA is
introduced into the animal, using recombinant DNA
technology, and then must be transmitted through the germ
line so that every cell, including germ cells, of the animal
contain the same modified genetic material.
3. History of transgenic Animals
The first transgenic animal was produced in 1982-
1983, when genes for human growth hormone were
introduced into mice (Supermouse by Ralph Brinster
and Richard Palmiter). In 1985, the first genetically
engineered sheep and pigs were presented to the
public.
4. Production of Transgenic Animals
• Microinjection
• Embryonic stem cell transfer
• Nuclear Transfer
5. 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.
6.
7.
8. Nuclear Transfer
• Removing the nucleus of an unfertilized egg and replacing it
with the nucleus of a donor 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.
12. Advantages
• Transgenics creates new medicines and treatments for
illnesses
• Benefits agriculture and industries, by being more profitable
(see Applications page)
• Constructs disease resistant animals and humans
• Transgenics is not only for animals, also for plants can be
applied to plants - more nutrients
• This will lead to more discoveries in science
13. Disadvantages
• Animals have a low survival rate
• Usually leads to breeding problems
• Leads to mutations and functional disorders
• A new disease could be created
• Ethical issues
