Post on 01-Apr-2015
GM-FoodsGM-Foods
What? Why? How? What for?What? Why? How? What for?
Examples of traits found in GM FoodsExamples of traits found in GM Foods
Disease-resistanceDisease-resistance
GM Papaya resistant to Papaya ringspot virus
Papaya
Examples of traits found in GM FoodsExamples of traits found in GM Foods
Pest-resistancePest-resistance
European Corn Borer
Herbicide ToleranceHerbicide ToleranceRoundUp Ready
Examples of traits found in GM FoodsExamples of traits found in GM Foods
Increased NutritionIncreased Nutrition
Golden Rice – Vitamin A
Medication, frost-resistance, salt tolerance, drought toleranceMedication, frost-resistance, salt tolerance, drought tolerance
How common are GM Foods?How common are GM Foods?
How common are GM Foods?How common are GM Foods?
How common are GM Foods?How common are GM Foods?
How are GM Crops made? Old How are GM Crops made? Old methodmethod
Old Method – Cross Old Method – Cross BreedingBreeding
Same speciesSame species
Takes many Takes many generations.generations.
Thousands of Thousands of yearsyears
Teosinte Modern corn
How are GM Crops made? Old How are GM Crops made? Old methodmethod
How are GM Crops made? New How are GM Crops made? New methodmethod
TransgenicsTransgenics
Can move genes from any living organism.Can move genes from any living organism.
GM Cotton resistant to boll weevil
Cotton
Advantages of GM FoodsAdvantages of GM Foods
Increased productionIncreased production
Decreased pesticide useDecreased pesticide use
Improved shelf-lifeImproved shelf-life
More land available for farmingMore land available for farming
Flavr Savr Tomato
Disadvantages of GM FoodsDisadvantages of GM Foods
No labelNo label
Allergy risk?Allergy risk?
Mixing of genes with wild relativesMixing of genes with wild relatives
Safe for human consumptionSafe for human consumption
Bt CropsBt Crops
Bacillus thuringiensisBacillus thuringiensis is a common soil is a common soil bacteria.bacteria.
Produces a protein - Produces a protein - toxic to certain insects toxic to certain insects (not humans)(not humans)
Toxin coats intestine Toxin coats intestine and larvae starve.and larvae starve.
Bt CropsBt CropsSprayed to control Sprayed to control both beetle, moth, both beetle, moth, and butterfly larvae.and butterfly larvae.
European Corn Borer European Corn Borer causes $1 billion in causes $1 billion in crop damage each crop damage each year.year.
RoundUp ReadyRoundUp Ready
RoundUp is an RoundUp is an herbicide used to herbicide used to control weedscontrol weeds
RoundUp Ready RoundUp Ready crops are resistant to crops are resistant to RoundUp.RoundUp.
RoundUp Ready ConcernsRoundUp Ready Concerns
Is it safe for the Is it safe for the environment?environment?– No-till land has No-till land has
increased 35%increased 35%
– Estimated 1 billion Estimated 1 billion tons of soil erosion tons of soil erosion preventedprevented
– 5% increase in 5% increase in herbicide useherbicide use
How Are GM Crops MadeHow Are GM Crops Made
Isolate GeneIsolate Gene
Place gene in “gene cassette”Place gene in “gene cassette”– Promoter – tells cell “beginning of gene”Promoter – tells cell “beginning of gene”– Transgene – codes for proteinTransgene – codes for protein– Terminator – tells cell “end of gene”Terminator – tells cell “end of gene”– Gives gene “context” otherwise it’s “just DNA”Gives gene “context” otherwise it’s “just DNA”
PROMOTER TRANSGENE TERMINATOR
How Are GM Crops MadeHow Are GM Crops Made
Transfer Gene to Transfer Gene to organismorganism
– Viruses or bacteria to Viruses or bacteria to infect cells infect cells (agrobacteria)(agrobacteria)
– Gene GunGene Gun
What are we doing in lab?What are we doing in lab?
Bring in a food item made of corn or soyBring in a food item made of corn or soy
Isolate DNAIsolate DNA
PCRPCR
Run and analyze GelRun and analyze Gel
What is our PCR detecting?What is our PCR detecting?
Tubulin – found in all Tubulin – found in all plants; cytoskeletonplants; cytoskeleton
CaMV35S promoter – CaMV35S promoter – strongstrong promoter from promoter from Cauliflower Mosaic Cauliflower Mosaic Virus; used in many Virus; used in many gene cassettesgene cassettes
Thinking AheadThinking Ahead
Will we be able to detect Will we be able to detect whatwhat trait our GM trait our GM Food has?Food has?
What is the purpose of detecting tubulin?What is the purpose of detecting tubulin?
No, detecting the promoter, not the transgene which codes for traits.
Control – helps us know if we successfully isolated DNA and set up PCR.
Why do we need to modify foods in Why do we need to modify foods in the first place?the first place?
??
Access to foodAccess to food
Need to feed millions of starving peopleNeed to feed millions of starving people
Only 10% of land is “arable” (can produce Only 10% of land is “arable” (can produce crops)crops)
Others?Others?
How are crops genetically How are crops genetically modified?modified?
Classical genetics (cross-breeding) vs. Classical genetics (cross-breeding) vs. transgenicstransgenics
http://www.teachersdomain.org/resources/http://www.teachersdomain.org/resources/tdc02/sci/life/gen/breeding/index.htmltdc02/sci/life/gen/breeding/index.html
How common is GM Food?How common is GM Food?
63% of all land used to grow GM crops is in U.S.
How common is GM Food?How common is GM Food?
Number of acres used for GM Farming is increasing world wide.
How common is GM Food?How common is GM Food?
In U.S. (2004)- 45% of corn (38% in WI)
- 85% of soybeans (82% in WI)
- 76% of cotton
GMO Free LabelsGMO Free Labels
GMO Free LabelsGMO Free Labels
How are transgenics made?How are transgenics made?
http://cls.casa.colostate.edu/TransgenicCrops/http://cls.casa.colostate.edu/TransgenicCrops/animation.htmlanimation.html
Determine which gene, Isolate DNA, cut out Determine which gene, Isolate DNA, cut out gene, paste gene into a plasmid, gene gun to gene, paste gene into a plasmid, gene gun to transfer DNA into plant cells, clone to produce transfer DNA into plant cells, clone to produce more transgenic plantsmore transgenic plants
What are some issues related to What are some issues related to GM-Foods?GM-Foods?
What types currently exist?What types currently exist?
How much of our crops are currently GM? How much of our crops are currently GM? How much of the food in the store?How much of the food in the store?
How would we know if something is GM or How would we know if something is GM or not?not?
What are some issues related to What are some issues related to GM-Foods?GM-Foods?
Is GM Food safe to eat? How safe is it?Is GM Food safe to eat? How safe is it?
Safe for the environment? Does it result in Safe for the environment? Does it result in more or less use of pesticides? More or more or less use of pesticides? More or less use of herbicides?less use of herbicides?
Who determines if it is safe or not?Who determines if it is safe or not?
What are some issues related to What are some issues related to GM-Foods?GM-Foods?
Can the genes escape into nature?Can the genes escape into nature?
http://www.teachersdomain.org/resources/tdc02/sci/life/gen/salmon/index.html
Which are GM traits are most Which are GM traits are most commonly used?commonly used?
Virus ResistanceVirus Resistance– Papaya, beetsPapaya, beets
Roundup Ready (herbicide resistance)Roundup Ready (herbicide resistance)– Canola, cotton, soybeans, cornCanola, cotton, soybeans, corn
Bt (pest resistance)Bt (pest resistance)– Cotton, corn, potatoesCotton, corn, potatoes– Harvest of Fear Video ClipHarvest of Fear Video Clip
Bt crop - concernsBt crop - concerns
Can insects develop resistance to Bt?Can insects develop resistance to Bt?
– Yes, but that’s true for non-GM insect-resistant Yes, but that’s true for non-GM insect-resistant crops as well.crops as well.
– Recommended that Bt crops be alternated with Recommended that Bt crops be alternated with regular crops.regular crops.
Bt crops - concernsBt crops - concerns
Is Bt safe for the Is Bt safe for the environment?environment?
69.7 million pounds less 69.7 million pounds less pesticide used in 2005.pesticide used in 2005.
Fewer “non-target” Fewer “non-target” insects such as monarch insects such as monarch butterflies are killed butterflies are killed compared to spraying.compared to spraying.
Can Bt crops still kill non-Can Bt crops still kill non-target insects?target insects?
Bt concerns?Bt concerns?
Is Bt safe for Is Bt safe for humans?humans?
– FDA considers Bt to FDA considers Bt to be safe for human be safe for human consumption. Digested consumption. Digested quickly.quickly.
– Humans have been Humans have been exposed to Bt for exposed to Bt for many years.many years.
RoundUp Ready ConcernsRoundUp Ready ConcernsCan the herbicide-Can the herbicide-resistance genes resistance genes move by pollen?move by pollen?
– ““Superweeds”Superweeds”
– Yes, but true for non-Yes, but true for non-GM herbicide-resistant GM herbicide-resistant crops as well.crops as well.
– Not a trait that will Not a trait that will allow it to outcompete allow it to outcompete in wild areasin wild areas
General GM Food ConcernsGeneral GM Food Concerns
Are GM Foods safe for the environment?Are GM Foods safe for the environment?– World’s 1950 grain output = 692 million tonsWorld’s 1950 grain output = 692 million tons
– World’s 2003 grain output = 1.9 billion tonsWorld’s 2003 grain output = 1.9 billion tons170% increase170% increaseSame number of acresSame number of acres
– Would need 1.8 billion additional hectares of Would need 1.8 billion additional hectares of land to produce same amount of grain by land to produce same amount of grain by 1950’s methods.1950’s methods.
General GM Foods ConcernsGeneral GM Foods Concerns
AllergensAllergens– What if new gene encodes a protein causes What if new gene encodes a protein causes
allergic reactions and/or death in people?allergic reactions and/or death in people?
– How would you predict if a food might contain How would you predict if a food might contain a new allergen?a new allergen?
RoundUp is considered “Friendly”RoundUp is considered “Friendly”
- It is virtually nontoxic to mammals, birds, fish, and insectsIt is virtually nontoxic to mammals, birds, fish, and insects
- - It exhibits essentially no pre-emergence activity. It won't prevent - It exhibits essentially no pre-emergence activity. It won't prevent plants in your garden from germinating.plants in your garden from germinating.
- - It exhibits essentially no residual soil activity even when applied at - It exhibits essentially no residual soil activity even when applied at high rates. Roundup binds tightly to soil particles and doesn't move on high rates. Roundup binds tightly to soil particles and doesn't move on or in the soil to affect untreated plants nearbyor in the soil to affect untreated plants nearby
- - It breaks down quickly into natural materials such as carbon dioxide - It breaks down quickly into natural materials such as carbon dioxide and nitrogenand nitrogen
- - It does not penetrate the woody stems of trees, shrubs, or grapevines - It does not penetrate the woody stems of trees, shrubs, or grapevines
- - Finally, the most important feature, once inside the plant, glyphosate - Finally, the most important feature, once inside the plant, glyphosate inhibits a key enzyme found only in plants and bacteria EPSP inhibits a key enzyme found only in plants and bacteria EPSP synthase. synthase.