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? 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 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 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.