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Genetic Engineering. “Amazing Schemes Within Your Genes”. What is genetic engineering?. Moving small pieces of DNA from one organism into another organism. What is recombinant DNA technology?. Same thing as genetic engineering
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Genetic Engineering “Amazing Schemes Within Your Genes”
What is genetic engineering? Moving small pieces of DNA from one organism into another organism
What is recombinant DNA technology? • Same thing as genetic engineering • Recombinant DNA – made by connecting (splicing) fragments of DNA from different sources
How does recombinant DNA work? • DNA is inserted into an organism • Organism uses foreign DNA as if it were its own
Transgenic organisms contain recombinant DNA (initial + “foreign”) What are these new things called?
How do scientists move DNA (genes) to make transgenic organisms? • Isolate source of foreign DNA to be inserted • Join DNA with a vehicle that can transport it • Transfer DNA (from chromosomes) into new host
How is DNA isolated? Restriction enzymes are used
What are restriction enzymes? • Proteins that come from bacteria • They recognize, bind to and cut DNA into smaller fragments at certain points • >200 different enzymes • Examples are: EcoRI, HinD III, Bam HI, Bgl II
Isolate source of DNA • Ex: EcoRI – cuts between G and A whenever it sees CTTAAG A G G T C T T A A G C T A G C T C C A G A A T T C G A T C G
Isolate source of DNA • Don’t cut straight through both DNA strands • Cut is offset by a few bases • “Sticky” ends are produced C T T A A G G A A T T C C T T A A G G A A T T C
Isolate source of DNA Ex: AluI – cuts between C and G whenever it sees AGCT A G C T T C G A A G C T T C G A • “Blunt” ends are produced
Isolate source of DNA Sticky Ends • DNA can form circle because complementary bases OR • DNA can pair with any other DNA fragment cut by the same enzyme (same bases exposed) = Recombinant DNA
REFRESHER: How do scientists move DNA (genes)? • Isolate source of DNA Answer: through Restriction Enzymes • Join DNA to a vehicle that can transport it Answer: ??? • Transfer DNA (from chromosomes) into target cell Answer: ???
Join DNA to a transport vehicle Vector – means by which DNA from one organism gets to target/host cell
Types of Vectors • Mechanical • Micropipette inserted into cell • Gene gun shoots tiny metal bullet coated w/ DNA • Biological • Virus • Plasmid
What is a plasmid? A small ring of DNA found in bacteria, which only carries genes under extreme circumstances Both plasmid and foreign DNA are cleaved w/ same restriction enzyme They are spliced using a “glue” called a ligase (enzyme)
How do we know if foreign DNA has been successfully transferred? • Host cell copies recombinant DNA and its own DNA • Clones are created as host continues to divide (all w/ desired DNA) • Foreign DNA codes for the production of a specific protein – test the cloned cells to see if they produce protein or not
And the final product is… • Newly recombined DNA that undergoes mitosis, producing multiple copies of new DNA • Bacteria is considered a good host because it reproduces quickly