The most common transgenic crops in use:
• Herbicide resistant plants (Roundup Ready)
Weeds are killed but crop plants survive.
(In U.S., about 80% of soybeans were GMO in 2003)
• Insect resistant plants (BT)
Express a bacterial protein that is toxic to insects
(In U.S., about 40% of maize
and
75% of cotton were GMO in 2003)
Insect resistance engineered via BT…
Bacillus thuringiensis---A spore-forming bacterium,
covered with a crystalline protein.
Crystals break down in alkaline conditions inside an insect
midgut-and form pores in insect membranes
European corn
borer inside a corn
stalk
29 years
21 years
27 years
Vitamin A (trans-retinol) deficiency:
In Southeast Asia, approximately 5 million
children develop xeropthalmia (impaired
vision) each year.
control
0.25 mil eventually go blind
correlated with diarrhea, respiratory
diseases, measles
According to UNICEF, Vitamin A
supplements could prevent 1- to 2-million
childhood deaths per year
From Ye, et al., (2000) Science, 287:303
Some other uses for transgenic plants…….
•Production of edible vaccines
•Wine without the hangover?---reduction of
bioamines to lessen chance of headaches associated
with wine drinking
•Caffeine-free coffee? Specifically shutdown
caffeine production in the plant
•Hay-fever treatment by rice consumption
Sequence encoding Green Fluorescent Protein (GFP)
NcoI site
Nucleotide
sequence
1 ccatggatgggtaagggagaggaacttttcactg gagttgtcccaatcttggttgagctcgacg
61 gtgacgtcaa tggacacaag ttttccgtct caggagaggg tgaaggtgat gcaacctacg
121 gaaagttgac ccttaagttc atctgcacta ctggaaaact ccctgttcct tggccaacat
181 tggtgaccac tttctcttac ggtgttcaat gcttctcacg ttacccagac catatgaagc
241 gtcatgactt tttcaagtcc gccatgcccg agggttatgt gcaagagcgt actatcttct
301 tcaaggacga cggaaactac aagacacgtg ccgaagtcaa gttcgaaggt gacaccttgg
361 tgaacagaat cgagttgaag ggtatcgatt tcaaggagga cggaaacatt cttggacaca
421 agcttgagta caactacaac tcacacaatg tgtacatcat ggctgacaag cagaagaacg
481 gaatcaaggt taacttcaaa atccgtcaca acattgagga tggaagcgtt cagttggctg
541 atcactacca acagaatact ccaattggcg atggccctgt gcttttgcca gacaaccact
601 acttgtccac ccaatctgcc ctttccaaag atcccaacga aaagagagac cacatggtct
661 tgcttgagtt tgtgaccgct gctggcatta cccacggcat ggatgagttg tacaagtaag
721 gatccaaagctagc
NheI site
Protein
sequence
Start codon (Met)
Stop
codon
MGKGEELFTGVVPILVELDGDVNGHKFSVSGEGEGDATYGKLTLKFICTTGKLPVPWPTLVT
TFSYGVQCFSRYPDHMKRHDFFKSAMPEGYVQERTIFFKDDGNYKTRAEVKFEGDTLVNR
IELKGIDFKEDGNILGHKLEYNYNSHNVYIMADKQKNGIKVNFKIRHNIEDGSVQLADHY
QQNTPIGDGPVLLPDNHYLSTQSALSKDPNEKRDHMVLLEFVTAAGITHGMDELYK*
Mice expressing GFP…
Limits of
biotechnology…?
Bacteria with coded messages...
Potential uses for transgenic animals
• Aquaculture
Increased growth via hormone gene insertion
From the July, 2004 issue of Scientific American
Gene Doping
“Gene therapy for restoring muscle lost to age or disease is poised to
enter the clinic, but elite athletes are eyeing it to enhance performance
Can it be long before gene doping changes the nature of sport? “
Belgian blue cattle – with a “double-muscle”
mutation that produces an altered form of myostatin
Support for agricultural biotechnology…
Biotech Holds “Enormous Promise”
for Developing World, says U.N.
Taken from http://www.whybiotech.com/ , an industry sponsored website
Opposition to agricultural biotechnology…
Activists dumped 4 tons of soybeans on Downing
St. at the home of British Prime Minister Tony Blair
after he said bioengineered food was safe to eat
Two kinds of objections to GMOs
1. Extrinsic
The potential harms of
GMOs outweigh the
potential benefits.
GMOs are too risky.
2. Intrinsic
GMOs are unnatural
and ought not to be
pursued, even if the
benefits outweigh the
harms. Playing God.
(slide from Gary Comstock)
Issues in Plant Biotechnology
• ENVIRONMENTAL CONCERNS
• FOOD SAFETY
• ETHICAL ISSUES
• GOVERNMENT/BUSINESS ISSUES
Environmental Concerns
•
•
•
•
•
•
•
•
Increased high-input monocultures
Does this technology encourage increased chemical use?
Effects on non-target organisms and wildlife
Development of “Superbugs” & “Superweeds”
Release of transgenic plants (or animals) into the wild
Added pressure and ability to farm marginal lands
Will cause an overall loss of genetic diversity
Spread of antibiotic resistance genes
ARE GMO PLANTS SAFE?
Ethics of Food Issues
– Do people have a right to know what they
are eating?
• Can consumers demand labels on everything
containing GM ingredients?
• Allergy issues?
• Can foods with animal genes inserted into them
still be considered strictly vegetables and
eaten as such? (Moral and religious concerns)
• Is it okay to express human genes in plants for
medical use? For consumption?
LABELING CONCERNS
In the U.S.
The FDA (Food and Drug Administration) has ruled that a food
should be labeled as a product of biotechnology only if changed in some
significant way. There is no mandatory labeling required.
GMO foods fit the criteria of
“SUBSTANTIAL EQUIVALENCE”
Mandatory laws require labeling of GMO products in:
Philippines
Saudi Arabia
Japan
Russia
South Korea
Mexico
Indonesia
New Zealand
Israel
Taiwan
Czech Republic
Norway
15 countries of the European Union
GOVERNMENT/BUSINESS ISSUES
•Several counties in California will vote in November
whether to allow or ban growth of any GMO crops
•Increased dependence on chemical and seed
companies
• Use of land in developing countries for testing ad
genetic “theft” from developing countries
• Is the U.S. trying to force GMOs on a hungry world?
Or is Europe practicing a “new colonialism”?
United States vs. EU
Food Aid Denied to Starving Population
November 5, 2002 By Lisa Schlein
Geneva - “The government of Zambia has asked the United
Nations World Food Program to remove thousands of tons of
genetically modified food that had been donated to the country.
The demand follows a decision last week by the government to
refuse donations of so-called GM food.
The World Food Program says the Zambian government has
told the agency to empty its warehouses and take all food which
has been genetically modified out of the country”.
(According to ActionAid, southern Africa's worst maize shortage
in living memory meant that by March 2003, over 14 million
people in Angola, Lesotho, Malawi, Mozambique, Swaziland,
Zambia and Zimbabwe faced serious food shortages)
U.S. Consumer Views
1. Knowledge of GMOs remains low
2. Opposition has softened in past few years
3. Consumers look to FDA for safety assessment
4. GM plants are more accepted than GM animals
5. GM use for medical/safety is more accepted
based on (9/15/03) Pew Initiative on Food and
Biotechnology Survey
(available at www.pewagbiotech.org)