Transcript Document

Lecture 24&25
Embryonic Stem Cell Method
Embryonic Stem Cell Method
• involves prior insertion of the desired DNA
sequence
• by homologous recombination into an in
vitro culture of embryonic stem (ES) cells
• ES cells are incorporated into an embryo
• at the blastocyst stage of development
Embryonic Stem Cell Method
• result is a chimeric animal
• method of choice for gene inactivation
• so-called knock-out method
What are stem cells?
• Stem cells are undifferentiated cells
• have the potential to differentiate into any type
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of cell (somatic and germ cells)
And give rise to a complete organism
harvested from the inner cell mass (ICM) of host
blastocysts
grown in culture and retain full potential to
produce all the cells of the mature individual,
including its gametes
Establishing transgenic mice with genetically
engineered ES cells
Positive – Negative selection
Testing for nonspecific integration and homologous
recombination in transfected cells by PCR
Gene disruption by targeted
homologous recombinant