Download FALSE SCIENCE

FALSE SCIENCE
Plant breeding
• Traditional breeding
is unpredictable. The
genes are mixed in a
random fashion.
• Genetic modification
is a precise
technique. Only one
gene is transferred
with a known
characteristic.
• During traditional
breeding only genes
of the parents are
mixed.
• In genetic
modification viral,
bacterial and
mammalian genes
are used.
GENE TRANSFER
• Only one gene,
with a known
characteristic is
transferred
• In practice, several
genes are inserted into a
GM plant:
– a promoter
– the transgene
– a terminator
– selection markers
– reporter genes
Traditional plant breeding
It involves movements of clusters of
functionally linked genes (with their
promoters, regulatory sequences and
associated genes) between
homologous chromosomes in a
coordinated fashion
Traditional plant breeding
We do not understand what is going
on during traditional (sexual) gene
transfer of a characteristics (coexpression/suppression, intronmediated enhancement,
transcriptional regulation, proteingene interaction, gene transposition)
rDNA vs. traditional breeding
• Random insertion of genes (without their
natural promoters and associated
regulatory genes) using viral promoters
and selectable markers from
incompatible species
• This technique resembles more the
process of viral infection than traditional
breeding
rDNA vs. traditional breeding
• We are learning the basics of gene
transfer
• Our ability is to transfer a precisely
defined construct not a defined biological
characteristic
• It is naive to presume that the transferred
gene(s) will work like any other gene of
the genome
Pleiotrophy (1)
• Pleiotrophy is defined as “production, by
one particular mutant gene, of apparently
unrelated multiple (or manifold) effects at
the pleiotrophic level.Regardless of the
plant breeding method used, pleiotrophic
effects occur at times and are ‘unexpected’
in the sense that their exact nature and
timing of occurrence in a breeding
population cannot be predicted .”
Pleiotrophy (2)
• Breeders recognize that such effects do
happen. Breeders look and select for
‘advantageous’ changes. Pleiotrophic
effects, then, are manifested at the
phenotypic level and may occur as a result
of conventional breeding as well as genetic
engineering. Really?(Spontaneous mutation
is rare in conventional plants but regularly
occur with GM!)
Pleiotrophy (3)
• Pleiotrophic effects are eliminated as part of
the product selection process and do not
affect food safety.
• To decide if pleiotrophic effects had
occurred one has to check
o the primary nutritional components
o if the toxins present are within the
expected range
o if the marker gene is at acceptable levels
Unpredictable aspects of GM
technology (1)
• Copy number of inserted gene varies
• Although the copy number and insertion sites can
be determined, but it cannot be predicted
• Location of insertion can lead to pleiotrophic
effects. They can be related to gene expression or
can be unrelated (due to changes associated with
expression of interrupted genes)
Unpredictable aspects of GM
technology (2)
• Construct are inserted at one locus (but not
the same locus for all lines
• Expression of an interrupted gene can be
reduced leading to activation of alternative
pathways
• Previously inactive genes can be activated
and something which was not produced
before will be produced now
Unpredictibility of rDNA technology
• Copy number of inserted gene varies
• Although the copy number and insertion sites can
be determined, but it cannot be predicted
• Location of insertion can lead to pleiotrophic
effects. They can be related to gene expression or
can be unrelated (due to changes associated with
expression of interrupted genes)
Production of toxic compounds
• rDNA ‘technology’ often leads to unexpected
metabolic, phenotypic and growth
aberrations
• Most plants produce toxic ‘defense’ proteins
against pests, animal predators and diseases
• Some of these are present but not expressed
normally. However, they can be activated
by a potent promoter
Antibiotic resistant selection
marker gene
• Assertion: These
antibiotics are not used
in human medicine. The
chances of transfer of
this gene to gut bacteria
are low, only 0.0001%
• Antibiotics are present in
animal feed and human
food; the contribution of
antibiotics in GM food is
negligible
• In reality:
Kanamycin is still in
human use and as all
GM plant cells
express it the EU will
prohibit the use of
this gene
We eat cauliflower mosaic virus
in large quantities
• With row broccoli
and cauliflower
we often ingest
the virus
• The CaMV 35S
promoter is not new
to us. We are eating
more in broccoli and
cauliflower than in
GM food.
• What we eat is the intact
virus, covered with its
protein coat.The coat is
responsible for host
specificity and it does
not bind to the
mammalian gut.
• However, the virus
promoter in the plant is
naked genetic material,
without specificity
Antisense DNA technology
• Assertion: It only
• In reality: The gene
silences one gene, no
new genes are
introduced
• It is the same gene
which is already
present in the plant but
it is inserted in a
reverse position
still goes in as part of
a construct which
has a promoter, a
marker gene, etc
• The inserted gene
behaves as any other
gene
GM crops are the same as any
traditionally grown variety
• Comparisons
between GM and
non-GM plants are
done on several
cultivars within a
single season and
growing location
• BUT composition normally
vary due to genetic and/or
environmental influences.
• Comparison must be done
always between the parent
and transgenic lines grown
under identical conditions
BT-GM CROPS
• BT has been used in organic
farming for decades and
nobody objected.
Why people object to it now?
• In BT crops not the bacteria,
only the effective part of the
bacterial toxin is encoded
HERBICIDE-RESISTANT
CROPS
• GM plants are
environmentally
friendly, they require
less herbicide
• For growing
herbicide tolerant
soyabeans more
herbicide is used
The limit for
herbicide residue in
food was increased
DIGESTIBILITY STUDIES
• All food contains
proteins and DNA,
which are fully
digested.
• We had millions of years
to get used to and digest
the protein and DNA in
traditional food. They
are familiar to our
digestive and immune
systems
• Now we are exposed to
new proteins and DNA
with unpredictable
consequences
DIGESTIBILITY
• Food based on genetically modified crops
represent novel proteins and genetic
materials, our gut and body have never
been exposed to. The consequences of
this are unpredictable.
• Longer time might be required for some
of the effects to develop, just like with
smoking.
We eat genes (DNA) all the time
• However, we have co• Our food contains
evolved with our
genetic material from
food, which was
plants and animal
carefully selected on
cells. When food is
the basis of trial and
processed, this can
error. Our digestive
partially be
and immune systems
degraded, but we eat
are familiar with
‘genes’ all the time.
foodstuff regularly
consumed
All food proteins are degraded in
the gut
• Most food proteins are degraded by digestive
enzymes produced by the gut or by bacteria.
However, a small proportion is only partially
degraded, or not degraded at all. The intact
proteins and small peptides can exert biological
functions: mimicking the action of hormones,
growth factors, bioactive peptides. Lectins are
notoriously resistant to degradation.
All DNA is degraded by the gut
• DNA is degraded to smaller units by the
digestive enzymes of the gut. However,
there is evidence to suggest that large
enough chunks of DNA (the size of a
gene) can survive digestion and absorbed
intact into circulation. Some DNA
sequences can also pass through the
blood brain barrier and the placenta.
Testing for toxicity
• It is difficult and time consuming to purify the
transgene protein from the plant, therefore the
pure protein for toxicology testing is produced
in bacteria.
• However, the stability of these two proteins
might be very different, specially if they are
glycosylated. Protein processing might differ in
pro- and eukaryotes.
World in Action (1)
• Scientists are altering the food since
generations. Plant breeding was
undertaken for thousands of years.
• However, it was done by traditional
methods only between closely related
species without mixing genes from
different life forms
World in Action (3)
• GM food is more tasty, more nutritious.
• Less herbicide will be used using
herbicide resistant crops.
• One of the first actions of GM producers
was to ask for increasing the limit of
herbicide residue in our food.
World in Action (4)
• Campaigners are scaring consumers with
non-existing risks.
• GM soy and maize have been subjected
to tests for 20 years.
• The first GM plant had been created in
1983.
• GM crops had the usual toxicity testing
World in Action (5)
• GM companies want a public debate
• All safety research is done by the
companies
• “One single paper ... may or may not be
scientifically valid, it may or may not be
something which needs investigation” (J.
Bainbridge)
World in Action (6)
• “DNA is degraded by powerful acid in
our stomach”
• “DNA survival is I suppose a remote
possibility”
• “Transfer of genes into human cells is not
a problem, this is not something that can
happen if we understand the complexity
of human genome” (J. Bainbridge)
World in Action (7)
• Decisions are made “on the basis of
scientific information available and
this is very very detailed… and the
Committee consists of 16 absolute top
scientific experts…. So we can look at
the facts and ensure that the food is
safe” (J Bainbridge)
Equinox (2)
• “we know the technology is not
dangerous and for forces of superstition
and ignorance out there to block this
technology is simply catastrophic” (Dr
Cyrus Ndirith)
• GM holds the promise of greatly reduced
costs, increased yields and healthier
plants
Equinox (10 )
• “There are some people who argue even that
eating these plants (GM) will transfer genes to
tumour cells or to the bacteria which live in
humans . These results are very unlikely, we
have been eating plants for millions of years. If
the transfer of genes from to humans could
occur, we already would be green and
photosynthetic. ” (Herrera-Estrella)
• “35% of genes found in humans can also be
found in plants.”
Equinox (10 )
• “There are some people who argue even that
eating these plants (GM) will transfer genes to
tumour cells or to the bacteria which live in
humans . These results are very unlikely, we
have been eating plants for millions of years. If
the transfer of genes from to humans could
occur, we already would be green and
photosynthetic. ” (Herrera-Estrella)
• “35% of genes found in humans can also be
found in plants.”
Panorama
• “When we eat the soy firstly both the
DNA and the protein are degraded and
secondly broken right done by the
stomach and the gut , so they are
equivalent.” (D Burke)
• On how long the animal test did last:
“Usually a month, 1 or 2 went over a
year” (D Burke)
Panorama
• “We knew a great deal about the
similarity and or difference of these foods
from conventional foods and this is our
surest test.” (D Burke)
• On how long the animal test did last:
“Usually a month, 1 or 2 went over a
year” (D Burke)
•
No risk from GM crops is based
on:
• Not different from traditional cultivars
• Antibiotic resistance gene has only few
copies (per plant cell!!!)
• Composition is essentially unchanged (it is
just checked for major nutrient)
• no adverse pleiotrophic effects are detected
or they are eliminated
Pleiotrophy (1)
• Pleiotrophy is defined as “production, by
one particular mutant gene, of apparently
unrelated multiple (or manifold) effects at
the pleiotrophic level.Regardless of the
plant breeding method used, pleiotrophic
effects occur at times and are ‘unexpected’
in the sense that their exact nature and
timing of occurrence in a breeding
population cannot be predicted .”
Pleiotrophy (2)
• Breeders recognize that such effects do
happen. Breeders look and select for
‘advantageous’ changes. Pleiotrophic
effects, then, are manifested at the
phenotypic level and may occur as a result
of conventional breeding as well as genetic
engineering. Really?(Spontaneous mutation
is rare in conventional plants but regularly
occur with GM!)
Pleiotrophy (3)
• Pleiotrophic effects are eliminated as part of
the product selection process and do not
affect food safety.
• To decide if pleiotrophic effects had
occurred one has to check
o the primary nutritional components
o if the toxins present are within the
expected range
o if the marker gene is at acceptable levels
Panorama
• “Genetic modification is going to lead to more
and better food, more nutritious and
wholesome food which is better to eat and
consumers can benefit from.” (D Griegson)
• “GM soy contains one additional gene in about
50,000 soy genes from a common soil bacterium
and a small gene from the petunia plant.” (D
Burke)
Panorama
• “We always have changed the genetic
make up of crops… nothing inherently
different about this.
• It is the regulatory bodies who approve
food safety and who have to decide
whether the food products needed to be
separated. “ (C Merritt)
The Basic Tenets of the GM
Biotechnology Industry:
• There is no “credible”evidence that GM
crops damage the environment
• There is no evidence either that GM
food can harm human/animal health
• Accordingly: they are as safe as their
“substantially equivalent conventional
counterparts” and need no testing
Are these views backed up by data published in
peer-reviewed science journals?
• A recent review concluded that the most pertinent
questions on environmental safety of GM crops have
not yet been asked let alone studied (Wolfanberger &
Phifer, Science, 2000)
• A recent review found only eight peer-reviewed papers
(four animal studies) published on the potential health
aspects of GM food (Domingo, Science 2000)
• Royal Society Canada report stated that “substantial
equivalence” is fatally flawed and regulation based on
it exposes Canadians to potential potential health risks
of toxic and allergic reactions
Is it accepted by all that GM crops/foods
are safe and no testing is needed?
• British Medical Association report: “Any conclusion
upon the safety of introducing GM material into the
UK is premature as there is insufficient evidence to
inform the decision making process at present”
• A majority of British consumers thinks that GM foods
are unsafe. As there is no demand for them most UK
supermarkets have phased them out
• All NGO-s oppose the introduction of GM crops/foods
on safety grounds and, as a minimum, demand their
rigorous, transparent and independent safety testing
PRESENT STATE OF GM FOOD
SCIENCE
• MANY OPINIONS BUT FEW DATA!
• NO PROPER HUMAN CLINICAL TRIALS
AND ONLY FEW ANIMAL STUDIES HAVE
BEEN PUBLISHED TO DATE
• THE INDUSTRY’S AND REGULATORS’
PREFERRED “SAFETY ASSESSMENT” IS
BASED ON THE POORLY DEFINED AND
NOT LEGALLY BINDING CONCEPT OF
“SUBSTANTIAL EQUIVALENCE”
GM FOOD SAFETY
• In the absence of safety studies the
lack of evidence that GM food is
unsafe cannot be interpreted that it
is safe
• Reliance on “substantial
equivalence” is dangerous and
unacceptable
Plant breeding – Assertions:
• Traditional breeding is unpredictable. The genes
are mixed in a random fashion.
• Genetic modification is a precise technique. Only
one gene is transferred
• The method of transfer of a gene of known and
safe function into a crop is technically neutral, so
the resulting crop must be safe and should not be
subjected to mandatory testing
IN REALITY:
The genome of the host plant is
not known (except for rice)
In traditional
breeding only
genes of the
parents are
mixed. In genetic
modification
viral, bacterial
and mammalian
genes are used
• The copy number
incorporated into the
genome is not always
assayed
• The location of the
insertion is not
always determined
Horizontal gene transfer
– Assertion: Genes from GM food are not
taken up by gut bacteria. Even if it occurs it is
rare, less than 1 to 10 million, while bacteria
regularly exchange of plasmids/genes
– In reality: The Newcastle trial with human
ileostomy patients showed that bacteria could
take up small amounts of full GM gene
constructs. As there are over 100 million
bacteria in the gut this is highly significant
IN REALITY:
• In Bt crops the effective part of the toxin is
expressed; the bacteria contains the protoxin
• In organic farming the bacteria is sprayed only
at high insect infestation
• The bacteria is only present on the surface of
the plant and destroyed by heat and rain.
• In the Bt-GM crops every cell expresses the
toxin all the time.
Conclusion
• The current GE crops/GE food on the
market were developed using an
unsophisticated technology, not tested
properly for safety and released
prematurely.
• Scientists, companies, regulators and
governments acted irresponsibly to allow
this to happen
Safety of GE plants
• The transgenic plant is not the sum of the
parent plant and the added gene product!
• Therefore, the risks associated with GE
plants are not the same as for traditional
plants
FACTS
• No risk from GM crops is based on: Not
different from traditional cultivars
• Antibiotic resistance gene has only few
copies (per plant cell!)
• Composition is essentially unchanged (it
is just checked for major nutrient)
• no adverse pleiotrophic effects are
detected or they are eliminated
Taking risks
We take risks because
• we understand what the risk is in advance
• we trust the assessors
• reward outweighs the risk
What are the risks of traditional plant
breeding?
What are the risks of GE plants?
Conclusion
• The current GE crops/GE food on the
market were developed using an
unsophisticated technology, not tested
properly for safety and released
prematurely.
• Scientists, companies, regulators and
governments acted irresponsibly to allow
this to happen
No risk from GM crops is based
on:
• Not different from traditional cultivars
• Antibiotic resistance gene has only few
copies (per plant cell!!!)
• Composition is essentially unchanged (it is
just checked for major nutrient)
• no adverse pleiotrophic effects are detected
or they are eliminated
Are these views backed up by data published in
peer-reviewed science journals?
• A recent review concluded that the most pertinent
questions on environmental safety of GM crops have
not yet been asked let alone studied (Wolfanberger &
Phifer, Science, 2000)
• A recent review found only eight peer-reviewed papers
(four animal studies) published on the potential health
aspects of GM food (Domingo, Science 2000)
• Royal Society Canada report stated that “substantial
equivalence” is fatally flawed and regulation based on
it exposes Canadians to potential potential health risks
of toxic and allergic reactions
Conclusion
• The current GE crops/GE food on the
market were developed using an
unsophisticated technology, not tested
properly for safety and released
prematurely.
• Scientists, companies, regulators and
governments acted irresponsibly to allow
this to happen
Conclusion
• The current GE crops/GE food on the
market were developed using an
unsophisticated technology, not tested
properly for safety and released
prematurely.
• Scientists, companies, regulators and
governments acted irresponsibly to allow
this to happen
Taking risks
We take risks because
• we understand what the risk is in advance
• we trust the assessors
• reward outweighs the risk
What are the risks of traditional plant
breeding?
What are the risks of GE plants?