Transcript GMO

Genetically Modified Organisms
Image credit: Microsoft clipart
What are genetically modified
foods?
 Also called genetically modified organisms (GMO),
or GE foods (Genetically engineered).
 Created by inserting DNA from one organism into
another (I.e. fish genes into apples) OR modifying
an organism’s DNA to attain a desirable trait. (I.e. a
tomato with reversed DNA to slow down ripening).
Image credit: Microsoft clipart
Genetic Engineering breaks the species
barrier!!!
• Genetic engineering allows DNA from different species
to be joined together.
• This often results in combinations of DNA that would
never be possible in nature!!! For this reason genetic
engineering is not a natural process.
• If DNA is transferred from one species to another the
organism that receives the DNA is said to be transgenic.
Alternative names for genetic engineering:
• Genetic Manipulation
• Genetic Modification
• Recombinant DNA Technology
• Gene Splicing
• Gene Cloning
Traditional Breeding
~25,000 genes
~45,000 genes
 technology is not essential,
 limited by species boundaries,
 all genes/traits are mixed.
Process of Genetic Engineering
Five steps involved in this process:
1. Isolation
2. Cutting
3. Insertion (Ligation)
4. Transformation
5. Expression
GM vs. Selective breading
Selective breading
-slow
-imprecise
-modification of genes that naturally occur in the organism
GM
-very fast
-precise
-can introduce genes into an organism that would not occur
naturally!
Why do it?
 Rice- not high in essential nutrients
Modification:
 + daffodil genes and a bacterium = beta-carotene
content drastically increased
 + genes from a french bean = double the iron content.
 Tomatoes- Introduce genes to increase shelf life.
Benefits #1
Increased crop productivity
 This includes herbicide tolerance,
 pest and disease resistance
 E.g. BT corn.
 Could mean using less spray
Image credit: http://www.public-domain-photos.com/ & Microsoft clipart
Benefits
#2
 Cold tolerance
 plants developed to tolerate cold
temperatures
 & withstand unexpected frost

could destroy seedlings
 Drought & salinity tolerance
 currently inhospitable regions can now
be cultivated
Image credit: http://www.public-domain-photos.com/
Benefits #3
 Improved nutrition
 crops like rice are a staple in
developing countries

nutritionally inadequate!
 GM "golden rice" is high in beta-
carotene (vitamin A)

Reduces eye-related problems like
blindness due to malnutrition
Image credit: http://www.public-domain-photos.com/ & Microsoft clipart
Benefits #4
 Future benefits might include:
 food without allergens; (I.e. anyone could eat nuts)
 longer shelf life and better taste (reduced food waste due
to spoilage)
 rice enhanced with iron (prevent anemia)
 foods used as vaccines (bye-bye needles)
 Many more possibilities
Image credit: Microsoft clipart
Milestones in Food
Biotechnology
 1994: FDA approves
“Flavr Savr” Tomato
 Prolonged shelf life
 Improved quality
 Voluntarily labeled
Other Genetically
Engineered Plants
 Agronomic traits
 BT Corn
 Disease Resistance
 Food quality
 Nutrition
 Metabolic products
 Vaccines
Bt Corn
 Natural insecticide from
Bacillus thuringiensis
 Non-toxic to humans
 Target insect: corn borer
 Potential to:
 reduce insecticide use
 reduce mycotoxins
 40% U.S. Corn crop Bt (2006)
Herbicide Resistance





Roundup Ready Soy, Corn, Canola
Allows post-emergence herbicide
spraying
Increases yield
Facilitates no-till farming
89% U.S. Soy crop (2006)
Disease Resistance
 Canola
 Cantaloupes
 Cucumbers
 Corn
 Rice
 Papaya
 Potatoes
 Soybeans
Genetically engineered papaya
resistant papaya ringspot virus
 Squash
 Tomatoes
 Wheat
Milestones in Food
Biotechnology
 1999: GM corn and soybean
products are present in 80%
of processed foods in USA
 Corn:
starch, high fructose corn
syrup, oil
 Soy:
 oil, protein

ENVIRONMENTAL CONCERNS
 Spreading of transgenes by GMOs to closely
related domesticated or wild relatives
 Spreading and invasion into natural
ecosystems by GMOs
 Spreading of transgenes from GMOs to
unrelated species
ENVIRONMENTAL CONCERNS
 Development of herbicide-resistant
weeds
 Development of insecticide-resistant
pests
 Damage to non-target organisms
interacting with GMOs
Herbicide Resistance Concerns
 Encourages herbicide use
 Groundwater contamination
 Kills beneficial soil microbes
 Cross-pollinates weeds
 Fosters dependence on
Agrochemcial companies
Spreading of GMO transgenes to
relatives
 GMOs targeted
 Possible effects on biodiversity
 Potential contamination of conventional
crops by GMOs
 Potential for development of herbicide-
resistant weeds
Transgene spread to unrelated
species
Spreading of transgenes by plants to
microbes with potential implications for:
 Infectious diseases controlled by antibiotics
 Potential for resistance to antibiotics
 Increases in the number of antibiotic resistance genes
ANIMAL AND PUBLIC HEALTH
CONCERNS
Effects of DNA, food and feed
derived from GMOs
Possible pathological effects
Health and Nutrition
 Golden Rice
 Vitamin A and Iron
enhanced
 Seeds given to the poor for
free