Transgenic Plants Production and Regulation

1
Transgenic PlantsProduction and Regulation

• Biotechnology and Society
• Spring 2007

2
Are Transgenic Plants Safe?
3
A Transgenic Plant

• If a plant that has one or more genes that have
  been artificially inserted
• These transferred genes are called transgenes.
• From a related or unrelated plant
• From a completely different genus
• Plants that acquire new genes through the process
  of pollination are not considered to be
  transgenic plants.

4
For example, transgenic corn contains the Bt gene
from Bacillus thuringiensis to control the corn
ear worm. Over 80 million acres planted annually
saving up to 2.4 billion in pesticide use
http//plymouth.ces.state.nc.us/pubs/btcorn99.html
5
US Federal Regulation

• Federal Agencies
• The US Department of Agriculture (USDA) Is it
  safe to grow?
• The Environmental Protection Agency (EPA) Is it
  safe for the environment?
• The Food and Drug Administration (FDA) Is it
  safe to eat?

6
Levels of Regulatory Oversight

• Institutional Biosafety Committee
• Animal Plant Health Inspection Service (APHIS) of
  the USDA
• The Environmental Protection Agency (EPA)
• The Food and Drug Administration (FDA)
• State Regulation
• International Agreements

7
Institutional Biosafety Committee

• Each institution that has bioengineering research
  has an IBC.
• The UI has a standing committee Biohazards
  Committee
• Composed of faculty from environmental sciences,
  law, a physician, and a research scientist.
• A safety officer, an industrial hygienist

8
The UI Biohazards Committee

• Advisory body to VP for Research and Graduate
  Studies.
• Research concerning living organisms.
• Evaluate potential risk to any life form or the
  environment.
• Individuals with expertise and experience to
  assess risk to public and environmental health by
  recombinant DNA technology.

9
UI Faculty Conducting Recombinant Research are
Required to

• Annually report to the committee all research
  involving recombinant organisms.
• Demonstrate level of containment.
• Develop a Memorandum of Understanding (MUA).
• Limit research relative to containment level.

10
Levels of Containment

• BL1 - Basic containment level. Restricted access
  to greenhouse insect, weed, and rodent control
  mechanisms screens recommended.
• BL2 - For agents of moderate potential hazard.
  BL1 requirements, plus Concrete floor screens
  restricting movement of small insects, but not
  pollen autoclave to sterilize transgenic
  material before removal. Our greenhouse is a BL2
  facility.

11
Levels of Containment

• BL3 - For agents of serious potential hazard.
  BL2 requirements, plus Collection and
  sterilization of liquid runoff sealed windows
  ventilation filters Security fence protective
  clothing.
• BL4 - For work with extremely hazardous agents,
  including certain exotic plant pathogens. Similar
  to BL3 but even more stringent.

12
APHIS

• http//www.aphis.usda.gov/
• Regulates the movement, importation, and field
  testing through permits and notification
  procedures.
• Genetically engineered plants and microorganisms
• Transgenic arthropods
• Products with applications such as veterinary
  biologics
• Plant pests, plants and plant products
• Animals and animal products

13
EPA

• Ensures the safety of chemical and biological
  pesticides
• Regulates the distribution, sale, use and testing
  of plants and microbes producing pesticidal
  substances.
• Sets tolerance limits for substances used as
  pesticides on and in food and feed.
• Regulates the sale and use of transgenic
  microorganisms.

14
FDA Center for Food Safety and Nutrition

• FDA regulates foods and feed derived from new
  plant varieties under the authority of the
  Federal Food, Drug, and Cosmetic Act.
• Requires that genetically engineered foods meet
  the same rigorous safety standards as is required
  of all other foods.
• Treats substances intentionally added to food
  through genetic engineering as food additives if
  they are significantly different in structure,
  function, or amount than substances currently
  found in food.

15
State Regulations

• Highly variable among states.
• Usually deferred to the investigating
  institution.
• Usually in compliance with US and international
  rules.

16
International Agreements

• International Biosafety Protocol, 2000
• International shipments that "may contain"
  transgenic food products must be so labeled
• Import requirements and restrictions be science
  based.
• A database of uniform information will be
  generated.
• Establishes and international framework for trade
  of transgenic crops.

17
Do We Need Transgenic Crops?
18

• Depending on where and for what purpose a
  transgenic plant can
• Result in higher yield.
• Result in improved quality.
• Confer pest or disease resistance.
• Confer tolerance to heat, cold and drought.

Provides an answer to Rachel Carsons Silent
Spring which alerted people to the dangers of
chemical pesticides.
19
Do we Need to Genetically Engineered Plants?

• Reduce the use of chemicals
• Protect the environment
• Increase the value of crops
• Reduce the risk of human medicines
• Increase the supply of human medicines
• Address difficult to solve problems

20
Do We Need Genetically Engineered Animals?

• Engineered Animals
• Leaner Meat
• Drug Production
• Transplant Organs
• Disease Resistance
• Accelerated growth
• Study gene regulation in animals

21
Do We Need Genetically Engineered Microorganisms?

• Pesticides
• Food Processing Aids
• Cheese production
• Animal Drug Production
• Posilac rBST, BST
• Human growth hormone, insulin, interferon,
  clotting factors, etc.

22
Cheese Production

• Pasteurization 72 oC for 15 minutes
• Conversion lactic acid bacteria
• Curdling
• Rennet Chymosin
• Chymosin extracted from the 4th stomach of 10 day
  old calves
• Cymosin is also found in
• Plants - Fig leaves, melon, wild thistle and
  safflower
• Fungi - Mucor miehei
• Bacteria - Bacillus subtilis or Bacillus
  prodigiosum
• Animal Pepsin, older cattle

23
CHY-MAX

• First Product of rDNA technology
• Pfizer, Inc. 1990
• FDA GRAS status Generally Regarded As Safe
• Identical to the enzyme extracted from calves
• Did not violate kashrus

24
(No Transcript)
25
KashrusCheese is now Kosher

• Only the meat and milk of certain animals is
  permitted. The Torah identifies these animals as
  having split hooves and 'chewing their cud'. In
  practical terms the only commonly used meat
  animals which are permitted are cows and sheep.
• Most commonly eaten birds (chicken, duck and
  turkey) are acceptable.
• All fish with scales and fins are acceptable.

26
Kashrus

• All insects, crustaceans, shellfish, and other
  invertebrates are forbidden. It is therefore
  necessary to be careful when eating certain
  vegetables to be certain that they are not
  infested with insects.
• Even permitted animals and birds must be
  slaughtered in a very specific manner. A trained
  professional must perform this slaughtering.
• It is forbidden to eat or cook milk and meat
  together.

27
Why CHY-MAX Went Unnoticed

• Enzyme, not a hormone
• Did not offend values of most people
• Did not threaten health
• Cheese makers benefited
• Increased, steady supply
• Milk Natures Most Perfect Food

28
Most People Love Cheese
29
Bovine Growth Hormone

• Bovine Growth Hormone (BGH)
• Bovine Somatotropin (BST)
• Recombinant BST rBST
• 190-191 amino acids long
• Injections 60 days prior to milking period
• Increases milk production by 20

30
FDA Drug Approval

• Safe to humans and to livestock
• Effective at the administered dose
• Drug can be produced with consistent and adequate
  quality

31
Opposing rBST

• Claimed unsafe for cows, causing mastitis or
  other ailments
• Not safe for humans
• The drug was not effective
• The drug was too effective and would drive down
  the price of milk
• Use would benefit large corporate dairy farms,
  ruining small dairy farms

32
Labeling
Milk from cows not treated with rBST. No
significant difference has been shown between
milk derived from rBST-treated and
non-rBST-treated cows.

• Despite a one year ban, and delays by opponents,
  rBST was found by the FDA to to save and
  effective
• no significant difference between milk from
  treated and untreated cows
• Labeling was not necessary
• Permitted voluntary labeling with disclaimer
• Used since 1994, and milk consumption has
  remained steady

33
Are Genetically Engineered Organisms Dangerous?

• Scientists do not know of any generic harms
  associated with genetically engineered organisms
  (mostly)
• It is not true that all genetically engineered
  foods are toxic
• It is not true that all released engineered
  organisms are likely to proliferate in the
  environment
• Mistakes will be made

34
Risks of Genetic Engineering

• However,
• We must assess the risk by virtue of the novel
  gene combinations the recombinant organism
  possesses
• Risk Assessment
• What are the potential adverse impacts?
• How likely are they to occur?
• Unexpected consequences?
• We may not know enough to identify risks
• Puts a burden on those wishing to demonstrate
  benefits
• Does not justify stopping the technology

35
Potential Harms

• Introduce new allergens in the food supply
• Antibiotic resistance
• Consumption
• Gene transfer
• Production of new toxins
• Activating inactive pathways
• Stimulating active pathways
• Concentration of toxic metals
• In inedible parts of the plant
• What if the switch is not completely off in the
  edible portions of the plant?

36
Potential Environmental Harms

• Increased weediness
• Introduction of a new species into a
  non-competitive environment
• Gene transfer to a wild or weedy relative
• Increased pesticide resistance in weeds and
  insects due to limited pesticide use
• Poisoned wildlife
• Creation of new or worse viruses via
  recombination of plant-viral genes and a
  different virus, or transcapsidation
• Unknown harms

37
Ethical Questions

• Are we unpredictably affecting the environment or
  human health?
• Who decides what is reasonable risk or rational
  justification?
• Are we subjecting particular groups to an unjust
  share of the risk?
• Are the benefits Unitarian or for certain groups?
• Is it ethically wrong to hold back rational
  benefits of the technology due to fear of risks
  (precautionary rule, unnecessary risk).