Transcript Slide 1

Lecture 20
Methods to produce transgenic
animals
What are Transgenic Organisms?

Transgenic
organisms are
organisms that are
injected with
foreign DNA from
another organism
http://www.unc.edu/~unclng/cow.jpg
How are they created?
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DNA
Microinjection
Retrovirusmediated gene
transfer
Embryonic stem
cell-mediated gene
transfer
DNA Microinjection

Direct microinjection of a chosen gene construct from
another member of the same species or from a
different species, into the pronucleus of a fertilized
ovum.
Retrovirus-mediated gene transfer
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Retroviruses are used as vectors
Infects host cells
Not all cells carry the retrovirus
The retrovirus must integrate into the germ
cells to work.
Embryonic stem cell-mediated
gene transfer
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Insertion of desired DNA sequence into an in vitro
culture of embryonic stem (ES) cells.
Stem cells can give rise to a complete organism.
The cells are then incorporated into an embryo at the
blastocyst stage of development.