Transgenic mice, first created in 1982 by R. Jaenisch and R. Mulligan, carry a foreign gene inserted into their genome through techniques such as pronuclear microinjection, embryonic stem cell-mediated gene transfer, and retrovirus-mediated gene transfer. These methods allow scientists to manipulate genes for various applications, including the development of model organisms like the 'oncomouse' which aids in cancer research. While offering advantages such as behavioral similarity to humans, transgenic mice also face challenges like high costs and difficult embryo manipulation.

1. TRANSGENIC MICE
Frist transgenic mice was created BY R. JAENISCH and
DR. R. MULLIGAN at MIT, in 1982
A transgenic mice is one that carries a foreign gene
that has been deliberately inserted into its genome.

2. TECHNIQUES
Pronuclear
Microinjection
Embryonic stem cell
mediated gene
transfer
Retrovirus mediated
gene transfer

3. Pronuclear Microinjection
In this method, a transgenic
DNA construct is physically
microinjected into the
pronucleus of a fertilized
egg. The injected embryos
are subsequently
transferred into the oviducts
of pseudo pregnant
surrogate mothers.

4. Embryonic stem cell
mediated gene transfer
This method involves prior insertion of
the desired DNA sequence by
homologous recombination into an in
vitro culture of embryonic stem (ES)
cells. These cells are then
incorporated into an embryo at the
blastocyst stage of development. The
result is a chimeric animal. ES cell-
mediated gene transfer is the method
of choice for gene inactivation, the so-
called knock-out method

5. Retrovirus mediated
gene transfer
Retrovirus-mediated gene
transfer. A retrovirus is a virus
that carries its genetic material
in the form of RNA rather than
DNA. Retroviruses are used as
vectors to transfer genetic
material into the host cell

7. APPLICATIONS
The Oncomouse The knockout mouse

8. ADVANTAGES
 Generated to carry cloned
oncogenes
 Behavioral similarity with
humans
 Easy to study the effect
of gene manipulation-
Model organism
DISADVANTAGES
 Expensive
 Embryos are not easily
accessible for
manipulation

9. REFERNCES
 Generation of transgenic mice
Andrew cho, Naoto Haruyama & Ashok B. Kulkarni Cell Biol.2009; unit-19.11
 Introduction of genes into the germ line of animals
Brinster RL, Palmiter RD
PRESENTED BY
 ARPITHA K
 MEENAKSHI S
 MUFASSIRA RAHMAN
 PREETHI SHALINI