Genetically Engineered Food

1
Genetically Engineered Food

• Waleed Kamel
• Phung Hinh
• Minqiang Jiang

2
Eat/Drink anything on this list?

• Cereal Cheerios, Wheaties, Golden Grahams, Corn
  Flakes, Frosted Flakes, Rice Krispies, Kellogg's
  Raisin Bran, Kraft Raisin Bran
• Sodas/Juices Coca Cola, Sprite, Pepsi, Mountain
  Dew, 7-Up, Dr Pepper, AW Root Beer, Fruitopia,
  Gatorade
• Candy Hersheys, Kit-Kat, Reeses, Nestle,
  MMs, Snickers, Milky Way, Twix

3
Foods containing no GE ingredients

• Cereal Breadshop Granolas, Down to Earth, Health
  Valley, Natures Path
• Sodas/Juices Odwalla, Mad River, Down to Earth,
  Mountain Sun, Whole Foods Juices
• Candy Endangered Species Chocolates, Rapunzel,
  Whole Foods

4
Where did these lists come from?

• True Food Network (www.truefoodnow.org)
• Affiliated with Greenpeace
• Conducted a campaign ending Nov 21, 2001 to
  convince Trader Joes grocery stores to drop GE
  ingredients from its private label products
• Can we believe their claims?

5
Coca Colas Response

• Biotech corn is used in combination with
  traditional varieties in some parts of the world
  to manufacture our ingredients
• but the high fructose corn syrup (HFCS) we use
  today is identical to the sweetener we used
  before the new corn varieties were available.
• The refining process for HFCS and other
  ingredients removes or destroys genetic material
  and protein so that the alteration in the
  biotechnology corn currently on the market does
  not affect Coca-Cola brand products in any way.

6
Other companies responses

• General Mills consumer letter Aug 2000 It's
  certainly possible that some of our products may
  contain ingredients that have been improved
  through biotechnology.
• Kellogg consumer letter April 2000 Kellogg
  Company uses grain from a number of suppliers, so
  our supply would likely include
  biotechnology-produced grain

7
How widespread are GE foods?

• About 60-70 of packaged foods contain GE
  ingredients
• Corn, soy, canola, and cotton make up 99 of all
  GE crops in the US
• In 2001, 50 of soybeans and 25 of corn grown in
  the US is GE (most is fed to animals)

8
US Public Opinion of GE foods

• Time Magazine, Jan 1999 81 of American
  consumers believe GE food should be labeled. 58
  say that if GE foods were labeled they would
  avoid purchasing them.
• ABC News.com poll, June 2001 93 of Americans
  say the federal government should require labels
  saying whether it's been genetically modified, or
  bioengineered.

9
International opinion of GE foods

• London requires restaurants to identify dishes
  containing GE ingredients (since 9/19/99)
• Many European countries and Japan require labels
• Mexicos leading producer of corn flour will no
  longer buy any GE corn. Mexico buys 500 million
  of US corn each year
• A Japanese trading house said it would import
  150,000 tons of non-GE soybeans from the US

10
Major Issues

• What are the benefits of using GE foods?
• What are the risks?
• Do the benefits outweigh the risks?
• Should foods containing GE ingredients be
  labeled?
• Would/Should consumers buy labeled foods?

11
Outline

• What is genetic engineering and how is it done?
  Minqiang Jiang
• Social benefits Phung Hinh
• Social costs and risks Waleed Kamel

12
What Is Genetic Engineering And How Is It Done?
13
What is a gene?

• every plant and animal is made of cells
• each cell has a nucleus
• inside every nucleus there are strings of DNA
• chromosomes--- structures organized by DNA
• each cell normally holds a double set of
  chromosomes, one of which is inherited from the
  mother and one from the father

14
What is a gene?

• the cell formed after fertilization divides into
  two identical copies, each of which inherits the
  new combination of chromosomes
• the inherited genetic material, carried in the
  chromosomes, is therefore identical in each new
  cell
• DNA --- a blueprint which contains all the
  essential information needed for the structure
  and function of an organism

15
What is a gene?

• genes --- the individual messages which make up
  the blueprint, each gene coding for a particular
  characteristic
• no gene works in isolation
• genes --- sequences of DNA which operate in
  complex networks that are tightly regulated to
  enable processes to happen in the right place and
  at the right time

16
What is a gene?

• informed and influenced by environmental feedback
  in relationships that have been evolving over
  millions of years
• the functioning of genes --- 'totally dependent
  on the environment in which they find
  themselves,according to Barbara McClintock, who
  won the Nobel Prize in 1983 for her pioneering
  work in the field of genetics

17
What is genetic engineering?

• traditional forms of breeding---variety has been
  achieved by selecting from the multitude of
  genetic traits that already exist within a
  species gene pool
• In nature, genetic diversity is created within
  certain limits
• A rose can be crossed with a different kind of
  rose, but a rose will never cross with a mouse

18
What is genetic engineering?

• when species that may seem to be closely related
  do succeed in breeding the offspring are usually
  infertile
• For example, a horse can mate with a donkey, but
  the offspring, a mule, is sterile.
• These boundaries are essential to the integrity
  of any species .

19
What is genetic engineering?

• genetic engineering--- involves taking genes from
  one species and inserting them into another in an
  attempt to transfer a desired trait or character
• For example, selecting a gene which leads to the
  production of a chemical with antifreeze
  properties from an arctic fish (such as the
  flounder) and splicing it into a tomato or
  strawberry to make it frost-resistant.

20
What is genetic engineering?

• possible for plants to be engineered with genes
  taken from bacteria, viruses, insects, animals or
  even humans
• genetic engineering is simply an extension of
  traditional breeding practices
• the food crops we are eating today bear little
  resemblance to the wild plants from which they
  originated
• clear differences between genetic engineering and
  traditional breeding

21
How is this done?

• Currently, the most widely used method for
  transferring genes into plants is
  Agrobacterium-mediated transformation
• Agrobacterium--- a naturally occurring pathogenic
  bacteria in the soil that has the ability to
  transfer its DNA into a plant's genome
• Agrobacterium infection and gene transfer
  normally occurs at the site of a wound in the
  plant, and causes a characteristic growth
  referred to as a crown gall tumor

22
How is this done?

• Scientists have taken advantage of this naturally
  occurring transfer mechanism, and have designed
  DNA vectors from the tumor-inducing plasmid DNA
  found in the bacteria that are capable of
  carrying desired genes into the plant
• The engineered or constructed genes are inserted
  into the Agrobacterium vectors and enter the
  plant by the bacteria's own internal transfer
  mechanisms

23
How is this done?

• Transformation is typically done on a small
  excised portion of a plant known as an explant
• This small piece of transformed plant tissue is
  then regenerated into a mature plant through
  tissue culture techniques

24
Summary

• traditional breeding
• hundreds of new plant varieties introduced every
  year in the United States
• all have been genetically modified through
  traditional plant breeding techniques--such as
  cross-fertilization of selected plants
• to produce desired traits

25
Summary

• genetic engineering
• actually an extension of traditional plant
  breeding
• involves direct modification of DNA, a living
  thing's genetic material
• more precise
• possible to direct and predict changes without
  introducing extraneous, undesirable traits
• allow scientists to introduce genes from
  essentially any organism into a plant

26
Overview

• The following is a photographic overview of the
  process of plant transformation and regeneration.
  The transformation of tomato is illustrated.
• http//www-ceprap.ucdavis.edu/Transformation/tran
  sform1.htm

27
A

• OBTAIN SEEDSShown are commercial tomato seeds.
  They are clean and ready to start the
  transformation process.

28
B

• SURFACE STERILIZE SEEDSTomato seeds are treated
  with a 50 bleach , 0.1 Tween (a detergent)
  solution to prevent the growth of microorganisms
  while in culture.

29
C

• GERMINATION The surface-sterilized tomato seeds
  are placed in a petri dish with nutrient medium
  for germination. Murashige and Skoogs (MS)
  medium is used in this case.

30
D

• CUT EXPLANTS After 7 days, the tomato seedings
  are at the stage where the cotyledons (explants)
  can be cut for use in transformation.

31
E

• PRE-CONDITION EXPLANTSThe cotyledon explants
  are pre-conditioned for transformation in a
  feeder plate. 
• The feeder plate is composed of an MS/agar plate
  with a layer of tobacco suspension callus on the
  agar.

32
F

• INSERT FILTER DISK A filter disk separates the
  explants from the feeder layer of tobacco cells.
  The feeder layer produces compounds that
  stimulate Agrobacterium to transfer DNA and help
  condition the cotyledon explants.

33
G

• CUT EXPLANTS
• The cotyledon explants are cut from the seedlings
  in liquid MS. The wounded cells made by cutting
  will be the site of DNA transfer from the
  Agrobacterium.

34
H

• EXPOSE TO AGROBACTERIUM After overnight
  preconditioning on the feeder plates, the
  explants are competent for transformation and are
  exposed to the agrobacterium.
•  

35
I

• BLOT EXCESS AGROBACTERIUM Excess agrobacterium
  is blotted from the explants on filter paper to
  avoid excess growth of the bacteria during
  co-cultivation.

36
J

• DNA TRANSFER The explants are co-cultivated
  with the agrobacterium for 48 hours to allow time
  for the agrobacterium to transfer the engineered
  DNA to the wounded plant cells.

37
K

• MEDIA PREPARATIONThe explants will be placed on
  a medium containing antibiotics for selection and
  control of the Agrobacterium. The medium also
  contains the growth regulator, zeatin riboside.

38
L

• POUR PLATESThe MSZ plates (MS plates containing
  zeatin riboside) are poured and allowed to
  solidify and dry overnight.

39
M

• PLATE EXPLANTSThe explants are then placed on
  the MSZ plates containing kanamycin and returned
  to the incubator to begin the regeneration
  process.
• Time point 1 day

40
N

• TOMATO PLANT REGENERATIONHere the formation of
  an initial callus can be seen on the explant. The
  callus occurs at the site of wounding and is a
  result of stimulated plant cell growth caused by
  the growth regulator, zeatin riboside.
• Time point 3 weeks
•  

41
O

• SHOOTS BEGIN After 6 weeks the cotyledon
  explants are cut from the calli and discarded.
  Shoots are beginning to form and are transferred
  to fresh MSZ media.

42
P

• ROOTING MEDIAThe tomato shoots have regenerated
  from the calli and are ready to be transferred to
  rooting media. This media lacks zeatin, but
  contains kanamycin for selection of
  transformants.
• Time point 9 weeks

43
Q

• TRANSGENIC PLANTSThese are fully differentiated
  transgenic tomato plants rooting in MS media with
  kanamycin.
• Time point 11 weeks

44
R

• TRANSFER TO SOILRooted plantlets are then
  transferred to boxes containing soil. The plants
  must be acclimated to the air, or "hardened off".
  The process takes 4-5 days.
• Time point 13 weeks

45
S

• TO THE GREENHOUSEThese transgenic plants are
  ready for transfer to the greenhouse. Shown are
  two cultivars of tomato Moneymaker (left), and
  Motelle (right). Both contain engineered genes.
• Time point 15 weeks

46
T

• A GREENHOUSE OF TRANSGENIC PLANTS. Plants and
  growth conditions are carefully monitored and
  controlled. The plants are used for analysis,
  seed production, or are transplanted to the
  field.

47
Potential Benefits of GM Crops
48
Agronomic Benefits

• More effective control of insect pests and weeds
• Now scientists are using the tools of advanced
  molecular biology to endow plants with genes that
  help them resist pests
• Although breeding practices have been used for
  years to develop crops with desirable traits,
  scientists can now pinpoint genes from similar
  species -- or even from completely unrelated
  organisms -- and transfer those protective genes
  into crops.

49
Agronomic Benefits

• Higher yields
• Grow more staple crops -- such as corn, rice,
  wheat, yams, and potatoes -- without further
  expanding the amount of land that must be
  cultivated
• In Kenya, biotechnology experiments are leading
  to increased production of bananas, potatoes,
  sugarcane, and commercially grown flowers.
• Biotechnology may help achieve the productivity
  gains needed to feed a growing global population

50
Health Benefits

• Increase the nutritional value of foods
• Staple foods can be altered to yield more
  vitamins and used to combat malnutrition in poor
  nations
• genetically-modified rice known as golden
  rice,'' aimed at combating Vitamin A deficiency,
  responsible for half a million cases of
  irreversible blindness and up to a million deaths
  a year among the world's poorest people
• rice variety rich in iron and zinc that may help
  combat anemia, which impairs immunity and reduces
  physical and mental capacity

51
Health Benefits

• Food to deliver Medicine/Vaccines
• Food will be the most widely used form to
  distribute medicine. The distinction between food
  and drugs will gradually disappear
• Bananas were already being genetically modified
  in research laboratories for all types of
  medicinal purposes, including immunization
  against four strains of anthrax
• There is still an urgent need for affordable and
  reliable vaccines the cost of traditional
  vaccines (production, maintenance and delivery)
  are often too high for them to be distributed
  widely in developing countries

52
Health Benefits

• Prevent Food allergies
• GM crops will become important in lowering
  allergic reactions to foods. Eight foods account
  for 90 of all food allergies these include
  peanuts, milk, eggs, soybeans, and wheat.
• Foods that cause allergies contain tens of
  thousands of proteins, of which only a few
  perhaps two to seven are actually responsible.
  So, it's certainly possible to take a gene from a
  food that causes allergy and show that it's safe
• antisense technology, in which the production of
  the offending protein directed by a gene is
  either greatly reduced or shut off
• modify the amino acid sequences in allergenic
  proteins

53
Environmental Benefits

• Clean Contaminated Soil Water
• The serious problem of soil contaminated with
  heavy metals or organic chemicals affects human
  health, ecosystem functions and agriculture.
  Phytoremediation uses plants to degrade, remove
  or stabilize toxic compounds from contaminated
  soil and water.
• Researchers have found a gene that improves
  alfalfa's tolerance to acid soil and aluminum and
  lets it naturally produce more nitrogen to
  stimulate plant growth

54
Environmental benefits

• Environmentally friendly
• Genetic information can be saved for species of
  trees being threatened around the world
• A reduction in the overall amount of pesticides
  used in crop production, which impacts positively
  on biodiversity, protects predators and
  non-target organisms, and contributes to a safer
  environment
• Conservation of soil moisture, structure,
  nutrients and control of soil erosion through no-
  or low-tillage practices as well as improved
  quality of ground and surface water with less
  pesticide residues
• Biotechnology offers significant prospects for
  conserving biodiversity by limiting destructive
  practices while obtaining higher and more stable
  yields on less land

55
Economic Benefits

• Higher profits for farmers
• Improved pest control, lower cost of production
  and improved yields, all contribute to a greater
  economic advantage to farmers who utilize the
  technology to develop more sustainable farming
  systems.

56
Social Benefits

• Food is more nutritious and affordable
• Benefits for poorer nations
• More resilient (drought proof)
• Higher yield
• Increased protein content

57
Social Costs and Risks of Genetically Engineered
Foods
58
Genetically Engineered Allergies?

• GE can be used to eliminate allergens from foods,
  but it can also introduce them
• GE foods can contain new proteins that behave
  like allergens
• Biotech companies test GE foods against known
  allergens before releasing the product
• Allergens from brazil nuts where transferred to
  soybean plants, but a test caught this and the
  product was never marketed

59
GE Allergies Example

• Starlink, a GE corn which contains a bacterium
  gene, was determined to have allergen properties,
  so it was approved by the EPA for use in animal
  feed only
• A mistake caused Starlink to be used in dozens of
  products, like taco shells and chips
• The products were quickly recalled, but not
  before 44 people had possible allergic reactions
• Starlink is no longer grown GE food must now be
  safe for humans to eat to be approved

60
GE foods could affect resistances

• Some GE crops contain genes giving them
  antibiotic resistances
• The resistance gene could somehow spread from the
  crops to harmful bacteria
• Similarly, some GE crops are pesticidal and could
  speed up development of pesticide resistance in
  insects

61
The Virus Hazard

• Most GE crops contain genetic material from
  viruses to activate the inserted gene
• An infecting virus could combine with the virus
  gene in the GE crop
• The new virus could be more infectious, cause
  more serious diseases, and have a greater ability
  to cross species borders

62
Do GE foods require approval?

• US Dept of Agriculture must certify that the food
  does not harm other crops
• If a GE crop makes its own pesticide, the EPA
  must review company tests and approve the
  pesticide as safe for humans and environment
• Other GE crops are regulated by the FDA, which
  does not require a formal approval process
  because they are seen as similar to non-GE crops

63
GE food might not reduce hunger

• Some believe world hunger is caused by poverty
  and politics, not lack of food, so increasing
  food supply does not reduce hunger
• In fact, if GE food negatively impacts small
  scale farmers, it could increase poverty, thus
  increasing world hunger

64
How GE food impacts farmers

• GE crops require high inputs and often tie farmer
  into contracts with a large company to continue
  to buy seed and chemicals, so are not well-suited
  for small scale farmers
• Terminator technology biotech firms make GE
  seed sterile so farmers cannot save seeds for the
  next season, which erodes farmers profits
• Crops normally grown in tropical regions can be
  engineered to grow in Northern countries, which
  could take jobs from poor countries

65
Biotech firms control food supply

• Companies patent GE seeds, which can be used to
  monopolize the crop
• Using GE foods narrows the gene pool of major
  food crops, leaving them vulnerable to rare
  diseases or uncommon insects
• Could allow companies to exert pressure on food
  prices since they are only source of GE seeds

66
Religious Controversy

• Genetic engineering is tampering with Gods
  design?
• If a corn plant were engineered with a gene from
  a cow, could a vegetarian eat it? Could a Jew or
  Muslim eat steak from a cow engineered with a pig
  gene?
• Religious leaders unsuccessfully sued the FDA in
  1998 claiming that not labeling GE food violates
  the right to religious freedom

67
Summary of Social Costs/Risks

• While there are many benefits to GE food, there
  are also many costs and risks involved
• This is such a controversial issue not only
  because people have different tolerances to
  risks, but also because people are not
  knowledgeable about the issue
• Perhaps the most significant problem is that
  people say they would not eat GE food, yet they
  do every day

68
Conclusion

• To date more than 98 million acres of genetically
  modified crops have been grown worldwide.
• No evidence of human health problems associated
  specifically with the ingestion of these crops or
  resulting food products have been identified.
• Noticeably absent from the first generation of GM
  crops have been varieties that bring direct
  consumer benefits. 92 of GM crops planted in
  1999 were modified for only two characteristics
  either herbicide resistance or insect resistance.