FALSE SCIENCE Plant breeding Traditional breeding During traditional
FALSE SCIENCE
Plant breeding • Traditional breeding • During traditional is unpredictable. The breeding only genes are mixed in a of the parents are random fashion. mixed. • Genetic modification • In genetic is a precise technique. modification viral, Only one gene is bacterial and transferred with a mammalian genes known characteristic. 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)
r. DNA 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
r. DNA 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 r. DNA 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 • r. DNA ‘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 Ca. MV 35 S 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 • BUT composition normally between GM and non vary due to genetic and/or environmental influences. -GM plants are done on several cultivars • Comparison must be done within a single season always between the parent and transgenic lines grown and growing location 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 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 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 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 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?
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