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Genetically Genetically Modified Modified
FoodsFoods
What is a Genetically What is a Genetically Modified (GM) Food?Modified (GM) Food?
Foods that contain an added gene Foods that contain an added gene sequencesequence
Foods that have a deleted gene Foods that have a deleted gene sequencesequence
Animal products from animals fed Animal products from animals fed GM feedGM feed
Products produced by GM Products produced by GM organisms organisms
Why are foods Why are foods genetically modified?genetically modified?
Genetic engineering offers a rapid Genetic engineering offers a rapid and precise method of altering and precise method of altering organisms as compared to organisms as compared to traditional methods that are slow traditional methods that are slow and inaccurate.and inaccurate.
VegetablesVegetables TomatoesTomatoes PotatoesPotatoes RiceRice CheeseCheese MeatMeat
Their genes are usually modified to make the crops pest or herbicide resistant
Examples of GM foodExamples of GM food
55
Examples of GM foodExamples of GM food
1994: Flavr Savr1994: Flavr Savr©© tomato tomato
– the first approved GM food product
- tomato genes are usually modified to delay ripening and softening
How is genetic How is genetic modification possible? modification possible?
The components of DNA are the same The components of DNA are the same in all organisms. in all organisms.
Sequences that code for proteins can Sequences that code for proteins can be moved from one organism to be moved from one organism to another.another.
How can DNA be moved How can DNA be moved from one organism to from one organism to
another?another?
Its quite simple,
REALLY!!!
How can DNA be moved How can DNA be moved from one organism to from one organism to
another?another?
►Find an organism with the desired trait
►Isolate the gene sequence that codes for the desired trait
►Insert the gene sequence into the genome of the plant cell
How can DNA be moved How can DNA be moved from one organism to from one organism to
another?another?
►Allow the genetically altered cell to grow into a plant
►Allow the plant to propagate
How can DNA be moved How can DNA be moved from one organism to from one organism to
another?another? A vector can A vector can
carry DNA. The carry DNA. The vector can be a vector can be a pellet from a pellet from a gene gun. gene gun. Viruses and Viruses and bacteria also bacteria also can be utilized can be utilized to transfer to transfer genes.genes.
Role of GM Foods in EMsRole of GM Foods in EMs Very important for developing countries/EMs
– By 2050pop. 9b food strategy for next 20 yrs– Need more food, as such hunger and starvation– 3m deaths/year in Africa solely relating to hunger– 3 options: aid/food, money/funds, provide GM foods
GM foodsGM foods: Rapid, accurate,↑ yield, ↓labor, ↑shelf-
life
Advantages of GM Advantages of GM Foods…Foods… Pest resistance
– Crop loss due to insets financial loss to farmers– So, farmers use tons of pesticides/fertilizers annually– GM eliminates pesticides and thus ↓ cost of
production Disease resistance
– Viruses, fungi, bacteria plant diseases– GM crops resistance to these diseases
Cold resistance Frost can destroy sensitive seedlings
– Antifreeze gene from cold fish tobacco and potatoes
Advantages of GM Foods Drought resistance
– More population ↑ land for housing, ↓ land for farming
– Land unsuited for plant cultivation Africa, dessert– GM crops grow in draughts or ↑ salt-content soil
Nutrition– Single crop (rice) cannot give all the nutrition needed– Lack vitamin A blindness common in EMs– GM food: golden rice has Vitamin A (beta-carotene)– GM food: with enhanced iron is underway, Europe?
Pharmaceuticals– Edible vaccines in tomatoes and potatoes– Easier to ship, store, administer than traditional
injections
Criticism of GM Criticism of GM Organism/Foods…Organism/Foods…
Criticism of GM Foods…Criticism of GM Foods… Environmental hazards
– Unintended harm to other organism Difficult to design toxin kills crop-damaging pests, not
other insects
– Reduced effectiveness of pesticides Develops resistance DDT
– Gene transfer to non-target species Cross-breeding Transfer of herbicide resistance from crops to weeds The “superweeds” will then have herbicide tolerance as
well
Solution– Create buffer zone
Criticism of GM Foods… Human health risks
– Allergenicity– We already have allergies to peanuts and other
foods…– Introducing gene may create more allergies– Unknown effects on human health– However, proposal to introduce a gene from
Brazil nuts into Soyabeans was abandoned
On the whole, with the exception of possible allergenicity, scientists believe that GM foods do not present a risk to human health!
Criticism of GM Foods Economic concerns
– Lengthy and costly process– May be patented
Monsanto, Novartis, Dow, DuPont hold patents for GM crops Make substantial profit by exporting it to EMs
– Farmers from developing countries/EM cannot afford– More gap between rich and poor
Other invention discouraged/stopped– Suicide gene technology
Only one growing per season Next time would produce sterile seeds that do not
germinate
Governments and GM Foods…Governments and GM Foods…
2009: 25 countries
Governments and GM Governments and GM FoodsFoods Europe: Europe: Anti-GM protests (Austria, France, Hungary)Anti-GM protests (Austria, France, Hungary) Japan: Japan: GM testing is mandatory. Customers for organic USA: FDA GM foods are substantially equivalent to
natural food, so not subject to FDA regulations– GRAS Generally Recognized As Safe
India: No policy yet for GM ↓ poverty Brazil: Some states have banned GM crops
– ↑Smuggle to compete with grain-exporting countries Africa: EU opposes the use of GM in Africa
– S. Africa, Sudan, Zimbabwe have GM laws; Kenya Act 2009 Argentina: Indifferent New Zealand: NO GM Foods grown here!
GM Food LabelingGM Food Labeling No need to label No need to label same wrt to nutrition same wrt to nutrition Europe and Japan Europe and Japan Mandatory Mandatory
– 1% contamination of unmodified products with GM 1% contamination of unmodified products with GM foodsfoods
– Consumers have the right the know the Consumers have the right the know the informationinformation
– Let consumers decide Let consumers decide but no choice but no choice– Reduced sales, so processors do not sell GM foodsReduced sales, so processors do not sell GM foods– EU has disguised policy of protectionismEU has disguised policy of protectionism
Canada and US Canada and US Voluntary Voluntary– Mandatory for Non-GM foodsMandatory for Non-GM foods– Let consumers decide Let consumers decide more choices more choices
Homework Homework AssignmentAssignment
How do you feel about GM foods? How do you feel about GM foods? Are they beneficial or harmful?Are they beneficial or harmful? Compare and contrast articles of your Compare and contrast articles of your
choice choice Write a short report on your views Write a short report on your views
about GM foods.about GM foods.
Possible Risks Possible Risks of GM Foodsof GM Foods
Insects might Insects might develop resistance develop resistance to pesticide-to pesticide-producing GM producing GM crops crops
Herbicide-tolerant Herbicide-tolerant crops may cross-crops may cross-pollinate weeds, pollinate weeds, resulting in resulting in "superweeds""superweeds"
Possible Risks Possible Risks for GM Foodsfor GM Foods
Certain gene Certain gene products may be products may be allergens, thus allergens, thus causing harm to causing harm to human health human health
There may be There may be unintended harm unintended harm to wildlife and to wildlife and beneficial insects beneficial insects
Photo courtesy of T. W. Davies, Cal. Acad. of Sciences.