Transcript Timeline of Genetic Engineering

GENETIC ENGINEERING
Chapter 15
15.1 Selective Breeding
Selective Breeding1.
intentional breeding of organisms
with desirable trait
attempt to produce offspring with
similar desirable characteristics
or with improved traits.
* before genetic engineering. It’s been around for a
long time.
Traits may be more milk produced, more
meat, grows faster, more eggs, etc.
Interesting Fact


In the 1950’s, it took 84 days to grow a 5 pound
chicken.
Now it only takes 45 days.
Speed Bump

What is an example of selective breeding that we
discussed earlier this semester?
Super Cow
before genetic ngineering
10,000 BC - Present

Selective Breeding
 Only
using select organisms from a group to create next
generation
 Race
horses
 Dogs
 Corn
– altitude
 Cattle – meat or dairy
 Larger/Taller/Stronger
 Miniature horses
Specific Types

Hybridization
 Crossing
dissimilar individuals to get an offspring with
the best of both traits

Examples
 Donkey
+ Horse = Mule (Horse’s Strength, Mule’s
Endurance.
 Pomelo + sweet orange = Grapefruit.
Inbreeding

Continued breeding of individuals with similar traits.
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

Less Diversity = Less Traits.
Inbreeding let’s us keep traits we want in an oragnism.
Example: Purebred Dogs
Bacterial Mutations

Cause organisms or organism’s offspring to mutate
and hope they turn into something useful.
 Use



radiation or mutagens to cause changes
Not super effective with animals
Super effective with bacteria (they grow faster)
Mutate organisms and select the ones with the
desired trait.
Polyploid Plants
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Extra Chromosomes = trouble
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In people, animals.
In plants, extra chromosomes work. (Somehow…?)
Use drugs that prevent chromosome separation in
meiosis.
Select the offspring with the desired traits.
What happens if we want something
more precise then selective breeding?


Something quicker?
Something more specific?
Genetic Engineering
a laboratory technique used by scientists to
change the DNA of living organisms
2. attempt to produce offspring with
desirable characteristics
3. or with improved traits
1.
Stronger corn stalk with larger ear of corn,
with resistance to insects, etc.
Selective Breeding vs. Genetic Engineering
1.
2.
3.
It usually take generations upon generations to
see a change occurring by selective breeding.
It took several hundreds of years to produce the
corn that we know today.
Genetic Engineering make the changes a lot
faster.
15.2 - RECOMBINANT DNA
AND GENE ENGINEERING
1973

Stanley Cohen and Herbert Boyer
 First
recombination
 First restriction enzyme – EcoR1

 1.
Named for bacteria isolated from – E.coli
Took frog DNA and bacteria
 2. Cut with restriction enzyme
 3. Glued with DNA ligase
 4. Placed into bacteria cell
 5. Bacteria made frog proteins
Before we begin…

We talked about
 Putting
Human Genes into bacteria – insulin
 Putting extra cow genes into cows – rBST

What about something just totally crazy.
Spider Goat
http://www.youtube.com/watch?v=6egCh0KmjuA
Spider Goat
1973 - Again

Stanley Cohen and Herbert Boyer
 First
recombination
 First restriction enzyme – EcoR1

 1.
Named for bacteria isolated from – E.coli
Took frog DNA and bacteria
 2. Cut with restriction enzyme
 3. Glued with DNA ligase
 4. Placed into bacteria cell
 5. Bacteria made frog proteins
Vocab


Genetic engineering - manipulating genes
Recombinant DNA-DNA made from two or more
different organisms
Gene Splicing
Example: Human gene from a chromosome is
transferred into bacteria.
 Insulin - protein hormone that controls sugar
metabolism
Before genetic engineering insulin was taken from the
pancreases of slaughtered cows and pigs, then purified
1982

First genetically engineered drug
 Insulin
Making Insulin
Step1 in Recombinant DNA
a. DNA (gene of interest) such as insulin code is cut
out of a persons chromosome
b. Restriction enzymes cut DNA between base pairs
c. DNA from a plasmid (found in bacteria) is cut open
using the same enzyme
d. Cut between specific DNA sequence producing
“sticky ends”
Step 1 Recombinant DNA
Step 2 Recombinant DNA
a.
The two are spliced together-enzyme
ligase
Human DNA
Bacteria Plasmid
DNA
b.
Recombinant DNA returned to
bacteria cell
Step 3 and 4
Step 3: Cloning
 Host
cell reproduces / gene reproduces
Step 4: Screening
 Good
cells separated from bad
 Genetic
Marker – an additional gene added to recombinant
DNA to determine if making the Recombinant DNA was
successful.
Recombinant DNA
Recombinant-DNA technology
Makes it possible to change the genetic
composition of living organisms.
Example: Honeycrisp apples
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exceptionally crisp and juicy texture
flesh is cream colored and coarse
flavor is sub-acid and ranges from mild and wellbalanced to strongly aromatic
outstanding flavor and texture can be maintained for at
least six months in refrigerated storage without
atmosphere modification
Selective Breeding vs. Genetic Engineering
1.
2.
3.
It usually take generations upon generations to
see a change occurring by selective breeding.
It took several hundreds of years to produce the
corn that we know today.
Genetic Engineering make the changes a lot
faster.
GEL ELECTROPHORESIS
Gel Electrophoresis
1.
2.
3.
4.
5.
DNA is cut into pieces with a restriction enzyme.
The DNA is cleaned up, protein is removed
DNA pieces are placed into a gel
The gel is placed in an electrophoresis chamber
The chamber is plugged in and the pieces of DNA
separate according to size
Gel Electrophoresis
Negative
electrode
Positive
electrode
Gel-filled with cut DNA from different people
Running the gel
1.
2.
3.
4.
Plug in the apparatus
Current moves through the buffer
When the current moves so does the DNA
Small pieces move fast then big pieces of DNAsmall pieces are farther away from the well.
Running the gel
Wells
DNA Fingerprint
DNA fingerprinting uses
1.
2.
3.
4.
Identify people
Identify body parts – war, accidents
Identify suspects
Identify organisms
DNA Fingerprints
Pattern of dark bands on film.
1.
DNA is cut using restriction enzymes
2.
Fragments are then placed in gel
3.
Electric charge moves DNA -> +
4.
Separate based on size
DNA fingerprint
1985
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DNA fingerprinting enters courtroom
 DNA
fingerprinting is the ability to match DNA from
crime scene with suspect DNA using gel electrophoresis
 Gel
electrophoresis is when you
 1. cut DNA with restriction enzyme
 2. pull fragments through gel using charge
 3. look at banding that results and match
PCR
Make a huge number of copies of a gene
Southern Blot


Southern blotting is designed to locate a particular
sequence of DNA within a complex mixture.
For example, Southern Blotting could be used to
locate a particular gene within an entire genome.
Southern Blot
CLONING
1997

Ian Wilmut clones sheep – Dolly


New-able to clone from ADULT cells
Embryonic cells were already cloned
Process
1.
Remove a mammary gland cell
2.
Remove an egg cell from another animal
3.
Remove the nucleus from the egg cell
4.
Fuse the mammary gland cell with the egg cell without a
nucleus
5.
Place the new fused cell into a surrogate mother
Cloning Dolly
USES OF GENETIC
ENGINEERING
Uses of Genetic Engineering
Medicines:
Pharmaceutical companies produce medically
important proteins using
bacteria.
 Diabetics
 Heart attack patients
 Factor VIII (blood clotting protein)
Uses of Genetic Engineering
Vaccines:
Primarily used to prevent viral diseases such as,
polio, smallpox, measles & influenza.
 Herpes
II virus
 Hepatitis B
GENETICALLY MODIFIED
ORGANISMS (GMO’S)
15.3
AND
A LITTLE BIT OF 15.4
1980

Supreme Court OK’s
patents for genetically
engineered organisms
 First
patent – Exxon
and oil-eating bacteria
Estimated at least 70% of all processed foods
contain GMO’s (truefoodsnow.org)

Crops
 Enhanced
taste and quality
 Reduced maturation time
 Increased nutrients, yields, and stress tolerance
 Improved resistance to disease, pests, and herbicides
 New products and growing techniques
 1986 Tobacco plant genetically engineered
 1992 Tomatoes that resist bruising engineered
Not a GMO
GM Products: Benefits and Controversies

Animals
 Increased
resistance, productivity, hardiness, and feed
efficiency
 Better yields of meat, eggs, and milk
 Improved animal health and diagnostic methods

Society
 Increased
food security for growing populations
GM Products: Benefits and Controversies

Environment
 "Friendly"
bioherbicides and bioinsecticides
 Conservation of soil, water, and energy
 Bioprocessing for forestry products
 Better natural waste management
 More efficient processing
GM Products: Benefits and Controversies
Controversies
 Safety
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
Potential human health impact: allergens, transfer of antibiotic resistance
markers, unknown effects Potential environmental impact: unintended
transfer of transgenes through cross-pollination, unknown effects on other
organisms (e.g., soil microbes), and loss of flora and fauna biodiversity
Access and Intellectual Property
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Domination of world food production by a few companies
Increasing dependence on Industralized nations by developing countries
Biopiracy—foreign exploitation of natural resources
GM Products: Benefits and Controversies

Ethics
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Labeling
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Violation of natural organisms' intrinsic values
Tampering with nature by mixing genes among species
Objections to consuming animal genes in plants and vice versa
Stress for animal
Not mandatory in some countries (e.g., United States)
Mixing GM crops with non-GM confounds labeling attempts
Society

New advances may be skewed to interests of rich countries
2003

Human Genome Project
completed
 Genome
– all of the
genes mapped out for
an organism
 Human Genome
Project mapped out
25,000 – 35,000
genes
Goals

The Human Genome Project was a 13-year, international
effort with the main goals of sequencing all 3 billion base
pairs of human DNA and identifying all human genes.
The Human Genome Project pinpointed genes and
associated particular sequences in those genes with
numerous diseases and disorders.
 It also identified about 3 million locations where single-base
DNA differences occur in humans.

What We Have Learned

More than 40% of our proteins are similar to
proteins in organisms such as fruit flies, worms, and
yeast.

This chart compares the human genome with other
organisms.
Gene Therapy
1. Process of changing a gene to treat a medical disease
or disorder.
2. Absent or faulty gene is replaced by a normal,
working gene.
3. This process allows the body to make the protein or
enzyme it needs, which eliminates the cause of the
disorder.
Treating Disease —
One Example of Gene Therapy

To deliver therapeutic genes to target cells
researchers engineer a virus that cannot reproduce or
cause harm.
Treating Disease —
One Example of Gene Therapy

The DNA containing the therapeutic gene is inserted
into the modified virus.
Treating Disease —
One Example of Gene Therapy
 The
patient’s cells are then infected with the
genetically engineered virus.
Treating Disease —
One Example of Gene Therapy

In theory the virus will insert the healthy gene into
the target cell and correct the defect.