Transcript Genetic Engineering

Genetic Engineering
What is genetic engineering?
• Application of
molecular genetics for
practical purposes
• Used to
– identify genes for
specific traits
– to transfer genes from
one organism to
another
– to cure diseases
Restriction Enzymes
• Bacterial enzymes that
cut DNA molecules into
pieces
• Each enzyme recognizes
specific sequences of
nucleotides and cut at
that site
• Can be used to isolate a
specific gene
Sticky Ends
• The “tails” of DNA that
are created when
restriction enzymes
cut DNA
• These sticky ends
can bind to other
sticky ends
Cloning Vectors
• A carrier that is used to clone a gene
• Also used to transfer a gene from one organism
to another
• PLASMIDS & Liposomes are an example
Plasmids
• A ring of DNA that is inside of bacteria
– Different from their main DNA
• Steps for gene-transfer
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Plasmid is removed from bacteria cell (host cell)
Plasmid is cut with restriction enzymes
A gene is inserted into the plasmid
Plasmid is returned to the cell
When cell replicates it clones the gene
The bacteria then infects other cells, giving them the
gene (bacteria cell is called a transgenic organism)
You can add a gene or cut out a gene
Recombinant DNA
• The combination of two or more pieces of DNA
• End result is that host cell transcribes the gene
as if it was it’s own DNA
DNA Fingerprinting
• A pattern of bands made
up of specific fragments
from an individuals DNA
• Uses
– Identify the suspect of a
crime
– Determine if 2 people are
related
– Compare relationship
between 2 species
Creating DNA Fingerprints (RFLP Analysis)
• Extract DNA (blood/tissue)
• Cut DNA into fragments using restriction enzymes
• Separate fragments using gel electrophoresis
– By SIZE
• Add radioactive probes complementary to DNA of interest
• Expose to photographic film
• Analyze results
Polymerase Chain Reaction (PCR)
• Used to make lots of
copies of DNA quickly
• Good for when we
only have a small
amount of DNA to
begin with