‘Sound science’ to the rescue
The misinformation and dis-information that led to Monsanto’s downfall are being perpetrated under the banner of ‘sound science’, starting with no less than the UK Royal Society, the core of the scientific establishment. Nineteen Fellows of the Society wrote to the papers accusing Pusztai of endangering ‘sound science’ in making public findings which have not been peer-reviewed and published in a scientific journal. The Royal Society then set up its own official review of Pusztai's unpublished work, declared it flawed, and warned that no conclusions should be drawn. The Society's Report(5) found no evidence of adverse effects from GM potatoes (but fell short of saying the GM potatoes were safe). And even if Pusztai’s experiments had been properly done, it stated that the results were only relevant to rats and potatoes, and it would be unjustifiable to draw conclusions on whether genetically modified foods in general are harmful to human beings. If animal testing is deemed to have no relevance for human beings, that would invalidate much of standard toxicological testing!
Pusztai’s findings were not the first to suggest GM foods might not be safe. Many scientists have been warning of different hazards inherent to the genetic engineering technology(6). Even the British Medical Association issued its own Interim Report in May, 1999, calling for an indefinite moratorium on GM crops and products, and for research to be done on the hazards of GM foods including new allergies, spread of antibiotic resistance genes and effects of the genetically modifed DNA in the GM crops (see later). The UK Government’s Chief Scientific Advisor agreed with a demand for a moratorium on commercial release until at least 2003(7). To top all that, research at Cornell University in the United States found that milk-weed leaves dusted with GM-maize pollen engineered with a bt-toxin from the soil bacterium, Bacillus thuringiensis, killed 44% of the larvae of the Monarch butterfly after 4 days, whereas no mortality occurred in larvae fed non-GM pollen(8). The public have good reasons to reject GM foods.
http://www.i-sis.org.uk/tide.php1. Horizontal gene transfer and genetic engineering
1.1
Horizontal gene transfer refers to the transfer of genes or genetic material directly from one individual to another by processes similar to infection. It is distinct from the normal process of vertical gene transfer - from parents to offspring - which occurs in reproduction.
Genetic engineering bypasses reproduction altogether by exploiting horizontal gene transfer, so genes can be transferred between distant species that would never interbreed in nature. For example, human genes are transferred into pig, sheep, fish and bacteria. Toad genes are transferred into potatoes. Completely new, exotic genes, can therefore be introduced into food crops.
1.2 Natural agents exist which can transfer genes horizontally between individuals.
These are viruses, many of which cause diseases, and other pieces of parasitic genetic material, called plasmids and transposons, many of which carry and spread antibiotic and drug resistance genes. These are able to get into cells and then make use of the cell's resources to multiply many copies or to jump into (as well as out of ) the cell's genome. The natural agents are limited by species barriers, so that for example, pig viruses will infect pigs, but not human beings, and cauliflower viruses will not attack tomatoes. However, genetic engineers make artificial vectors (carriers of genes) by combining parts of the most infectious natural agents, with their disease-causing functions removed or disabled, and design them to overcome species barriers, so the same vector may now transfer, say, human genes, which are spliced into the vector, into the cells of all other mammals, or cells of plants.
1.3 Typically, foreign genes are introduced with strong genetic signals - called promoters or enhancers - to boost the expression of the genes to well above the normal level that most of the cell's own genes are expressed. The most commonly used promoters are from plant viruses which are related to animal viruses (see below). There will also be selectable "marker genes" introduced along with the gene(s) of interest, so that those cells that have successfully integrated the foreign genes into their genome can be selected. The most commonly used marker genes are antibiotic resistant genes originally isolated from bacterial plasmids and transposons, which enable the cells to be selected with antibiotics. These marker genes often remain in the genetically engineered organisms.
1.4 One viral promoter which is in practically all transgenic plants is from the cauliflower mosaic virus (CaMV), which is closely related to human hepatitis B virus, and less so, to retroviruses such as the AIDS virus.
The CaMV promoter can drive the synthesis of these other viruses; it is active in most plants, in yeast, insects and E. coli. As all genomes contain dormant viruses, there is a potential for the CaMV promoter to reactivate them. Its strong promoter activity causes introduced genes to be overexpressed, and may also have effects on host genes far away from the site of foreign gene insertion. The promoter from another virus - the figwort mosaic virus, is similar to CaMV in many respects, and therefore equally hazardous. Recombination between the figwort and CaMV promoters in the same plant is bound to take place with untoward consequences for the crop plant, and also in creating new, broad host range viruses.
http://users.westnet.gr/~cgian/horizontal.htm
Printer-friendly format
Email this thread to a friend
Bookmark this thread
(1000+ posts)
Send PM |
Profile |
Ignore
