transgenic animals and

2. A transgenic animal is one whose genome has been changed to
carry genes from other species. The nucleus of all cells in
every living organism contains genes made up of DNA. These
genes store information that regulates how our bodies form
and function.

3. Man has always been trying to improve several traits in
domesticated animals, such as milk yeild,wool characterstics,
weigh gain, and egg laying frequency. the process included
selective breeding and and selection through several
generations. It was quite Successful. and time consuming and
very expensive . However ,recent devolpment in genetic
engneering have made it possible to introduce specific genes
into animals , and to create genetically altered or transgenic
animals with improved or new chacteristics

4.  A cloned gene is injected into the nucleus of a fertilized egg
 Fertilized egg, after injection of gene is implanted into the
uterus of a receptive female.
 The progeny derived from the implanted egg carry the cloned
gene in all their cells.
 Animals with the cloned gene integrated into their germ line
cells are bred to establish new genetic lines
 Thus a number of transgenic animals are produced

5. • The first transgenic animals were mice created by Rudolf
Jaenisch in 1974. Jaenish successfully managed to insert
foreign DNA into the early-stage mouse embryos; the
resulting mice carried the modified gene in all their tissues.

6. • To study promoter function ,reporter gene expression and
functions of transferred genes
• To produce new proteins from cultured cell lines ,by the
insertion and expression of genes coding for specific proteins
• To create transgenic animals with higher yield of milk or meat
• To obtain better quality milk ,meat ,wool , etc
• To produce transgenic animals with the capacity to synthesize
new proteins .such animals are used in gene Pharming
(Pharming means to producing Pharmaceuticals .
• To use animals as models for studies in gene therapy

7. Gene pharming is a technology that scientists
use to alter an animal's own DNA, or to splice
in new DNA, called a transgene, from another
species. In pharming, these genetically
modified (transgenic) animals are used mostly
to make human proteins that have medicinal
value.

8. TRANSGENIC MICE
• The technology for producing transgenic animals
has been perfected in the laboratory mouse
,foreign DNA can be introduced into mice by the
following method
• Using retroviral vectors that infect the cells of an
early stage embryo, prior to implantation into a
receptive female
• microinjection into the enlarged sperm nucleus
• Introduction of genetically engineered embryonic
stem cells into the early stage developing embryo
of female

9. DNA MICRO INJECTION METHOD
• This is currently the preferred method for producing the transgenic
mice this process involves many steps
• To inoculate fertilised eggs there is need to have enough eggs the
donor females are ,therefore ,stimulated to superovulate
• The females are given an injection of pregnant maresserum and
another injection after 48 hrs,of human chorionic gonadotropin
• The normal mouse produces 5-10 eggs, but the superovulated
mouse produces 35-40 eggs
• The super ovulated are mated and the fertilized eggs are taken
from their oviducts
• Immediately after their collection ,the fertilized eggs are
microinjected with the transgene construct

13. After inoculation ,25-30eggs are implanted into afoster
mother,however this process prepares the females uterus for
receiving eggs .copulation is the only way to prepare the uterus
for implantation after implantation of the microinjected fertilized
egg,the foster mother will deliver and release the pops in around
3 weeks

14. CLONING BY NUCLEAR TRANSFER
• A nucleus from a cultured cell can be transferd to an
enucleated egg and implanted into the uterus of a receptive
female animal. the egg will develop into embryo and finally
into offspring . if the nucleus is derived from the same animal
,the progeny will be clone offspring will be the the replica off
mother .the methodology was used for the much publicized
production of a sheep called dolly

15. IMPORTANCE OF TRANSGENIC MICE
 Short oestrous cycle
 Short gestation period
 Relatively short genaration time
 Production of several offspring per progeny
 Ease of in vitro fertilization and in vitro embryo culture
 Availabilty of a large number of genetic varieties

16. TRANSGENIC SHEEP

17. NUCLEAR TRANSFER IN SHEEP
• The nucleus of an ovum is removed with a pipette
• Cells from mammary epithelium of adult and the state is
induced by inhbiting cell growth
• The re nucleated ovum is grown in culture
• Then it is implanted into a foster mother ,where the
development proceeds to term
• The foster mother gives birth to transgenic lamb(young
sheep)

18. Nuclear transfer in sheep

19. TRANSGENIC SHEEP APPLICATIONS
• Some of the pharmaceutical products produced in the milk of
transgenic sheep are
• Clotting factors
• Soluble cd4 protein
• Lactoferin
• Urokinase
• CFTR
• Interleukin-2
• And high rate of milk,wool and meat yielding is seen

21. Other transgenic animals
• TRANSGENIC RABBIT
Rabbits are promissing for gene pharming for the production of
pharmacuetically or important protiens encoded by the
transgenes .the protein product is easily harvested with from
which it is conveniently purified

22. Transgenic cattle
• The only successful transfection technique in cattle is
microinjesction of fertilized ova which may either be
recovered surgically in vitro
• Increased milk rate
• pharming

25. TRANSGENIC PIGS
Pigs have been viewed as great experiment al animals for
transgenic research .first of all the human haemoglobin gene
have been expressed in pigs
Transgenic pigs have recently found favour as research materials
to produce organs for human transplants as human organs
are in short supply .pigs can be used as donors of kidney heart
etc. however due to hypercute rejection of foreign organs in
the human system .
The research in the direction has, again , along way to go

30. .............................

35. Questions on transgenic animals
1. Describe the application of transgenic
animals?
2. Discuss the DNA microinjection method is
carried out in producing transgenic mice?
3. What is meant by gene pharming?