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Section 1 – Genetic Engineering
Section 2 – Human Applications of Genetic
Engineering
Section 3 – Genetic Engineering in Agriculture
The process of manipulating genes for
practical purposes
Involves recombinant DNA
DNA made from two or more organisms
Example – First Genetically Altered
Organism
Bacteria produced frog rRNA
Step 1 – Cutting DNA
Genes of interest cut by restriction enzymes
Restriction Enzymes:
Bacterial enzymes that recognize and bind to
specific nucleotides
Vector
An agent used to carry the gene of interest to
another cell
Plasmids
Circular DNA that replicate independently
Step 2 – Making Recombinant DNA
Genes of Interest + Vector = Recombinant DNA
Transgenic organism
The organism produced through genetic engineering
DNA Ligase:
Bonds (glues) the DNA fragments together
Host cells take up the recombinant DNA to pass
on the genetically modified DNA
Step 3 – Cloning
Gene Cloning:
As host cell reproduces – exact copies of the
genes of interest are replicated
Gene of interest and plasmid are both replicated
Step 4 – Screening
The cells that picked up the genes of interest
are separated from the cells that did not
Only the modified genes are transcribed &
translated
Each end are known as sticky ends
In order to bond to the plasmid – they
must have complementary base pairing
Step 1 – Southern Blot
DNA cut by restriction enzymes and isolated
Step 2 – Gel Electrophoresis
Electric field that separates molecules by size
DNA is separated into single strands by gel
DNA is negatively charged – migrates to positive
pole
Small bands move the fastest
Step 3 – Probes
Radioactive or fluorescent tags that are
complementary to the genes of interest
Step 4 – Visible Bands
The strands will bind with the probes and create
visible bands within the solution
http://video.mit.edu/watch/geneticengineering-10959/
A project that links over 20 genetic labs in six
different countries
The purpose:
Identify all 3.2 billion base pairs of the human
genome
Human DNA:
6 feet long
30,000 to 40,000 genes
Expected Number: 120,000
Which is actual the number of mRNA molecules
Bacteria is
the source for
many GEDs
These drugs
are universal
for all body
types and
that’s why
they work
Vaccine:
Harmless version of human pathogen
The human body creates antibodies at the first
response so in future infections it can have immunity
Glyphosate
Biodegradable weed killer resistant
Crops were modified so they flourished
Rice Modification
DNA modified to contain iron and beta
carotene
Fights iron deficiency and improves vision
Potential Problems
Glyphosate resistant crops could lead to
glyphosate resistant weeds
Humans could be allergic to the gene insert to
modify the crops
Environment Effect
Pest can become resistant
GM crops could become the new wild plant
Growth Hormone in Cows
Increases milk production
Introduced through bacteria in their diet
Now naturally in pigs
Transgenic Organisms
Human proteins introduced to farm animal DNA to
produce human proteins in milk
Using undifferentiated cells from an adult animal to
produce an offspring through differentiation
Genomic imprinting
Chemical locking “on” and “off” of a gene
without DNA alteration
Use of methyl group – CH3
Cloning Failure
Egg divides in minutes which is too fast to
properly form specialized cells
A pattern of dark bands on X-ray film
Needs Polymerase Chain Reaction
Used to amplify and make multiple (millions
of copies) of the same DNA sequence
This must be done before DNA fingerprinting
process begins if sample is too small!
Process:
DNA cut by restriction enzymes between
CCGG
In gel – small fragments move to positive side
(DNA is negatively charged)
When bands line up – you can compare DNA
to see if they are matched
Example – Blood samples at crime scenes