Monday, November 21, 2011
How much insecticide do Bt plants actually produce?
November 21, 2011
New publication shows inadequacies in risk assessment
A new publication by an international research consortium has revealed several inadequacies in current approaches to risk assessment of genetically engineered plants. The publication deals with methods used for measurement in so-called Bt-plants. These plants produce an insecticidal protein ( a so-called Bt toxin) that originates from soil bacteria (Bacillus thuringiensis). One example is maize MON810 which is cultivated in some countries in the EU, many others can be imported and used in food and feed. Now for the first time, joint research involving four laboratories has shown that the results produced by industry and other institutions so far are not reliably reproducible and comparable because they are not determined and validated by standardized methods.
The actual content of these Bt toxins is highly relevant for assessing risks for the environment, and also for preventing resistance in pest insects. Without reliable data, the safety of these genetically engineered plants cannot be properly assessed.
Wednesday, October 5, 2011
Canadian GM canola has escaped into wilds of North Dakota
By Margaret Munro
October 5, 2011
Genetically modified canola has escaped from the farm and is thriving in the wild across North Dakota, according to a study that indicates there are plenty of novel man-made genes crossing the Canada-U.S. border.
GM canola was found growing everywhere from ditches to parking lots, the scientists report, with some of the highest densities along a trucking route into Canada.
“That’s where the most intense canola production is and it’s also the road that goes to the canola processing plants across the border,” said ecologist Cynthia Sagers of the University of Arkansas, referring to a canola plant in Altona, Man.
Her study stopped at the border, but Canadian research also have found “escaped” GM canola is becoming common on the Canadian prairies, and swapping man-made genes in the wild.
“Biology doesn’t know any borders,” said Rene Van Acker at the University of Guelph, who has done extensive research on the extent and behaviour of escaped GM crops in Manitoba.
For the study published Wednesday, Sagers and her colleagues drove across North Dakota and stopped every eight kilometres to see what was growing. At almost half of the 634 stops they found genetically modified canola.
Sunday, September 11, 2011
Pharm Crops Ignoring Health & Environment
By Prof. Joe Cummins
September 11, 2011
Pharmaceutical drug production has undergone major changes following the development and approval of drugs called ‘biologicals’ that are for the most part proteins produced by genetic engineering. Biologicals make up at least a quarter of new drug approved, though they are about twice as likely as chemical drugs to experience regulatory action following approval (see ‘Biologicals’, Wonder Drugs with Problems, SiS 42). The recombinant protein drugs are produced using viruses, bacteria, yeast, and cell cultures from insects, rodents, primates or humans. The use of genetically modified (GM) crop plants to produce biologics has been an attractive prospect because the crops are capable of producing vast quantities of recombinant proteins at low cost. There have been a large number of such transgenic ‘pharm crops’ created in the laboratory and field trialled, though none have been approved for commercial drug production. However, some have now progressed to clinical trials.
Friday, July 29, 2011
Field-evolved resistance to Bt maize by western corn rootworm
By Aaron J. Gassmann*, Jennifer L. Petzold-Maxwell, Ryan S. Keweshan, Mike W. Dunbar
(Department of Entomology, Iowa State University)
July 29, 2011
Background: Crops engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) are planted on millions of hectares annually, reducing the use of conventional insecticides and suppressing pests. However, the evolution of resistance could cut short these benefits. A primary pest targeted by Bt maize in the United States is the western corn rootworm Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae).
Methodology/Principal Findings: We report that fields identified by farmers as having severe rootworm feeding injury to Bt maize contained populations of western corn rootworm that displayed significantly higher survival on Cry3Bb1 maize in laboratory bioassays than did western corn rootworm from fields not associated with such feeding injury. In all cases, fields experiencing severe rootworm feeding contained Cry3Bb1 maize. Interviews with farmers indicated that Cry3Bb1 maize had been grown in those fields for at least three consecutive years. There was a significant positive correlation between the number of years Cry3Bb1 maize had been grown in a field and the survival of rootworm populations on Cry3Bb1 maize in bioassays. However, there was no significant correlation among populations for survival on Cry34/35Ab1 maize and Cry3Bb1 maize, suggesting a lack of cross resistance between these Bt toxins.
Conclusions/Significance: This is the first report of field-evolved resistance to a Bt toxin by the western corn rootworm and by any species of Coleoptera. Insufficient planting of refuges and non-recessive inheritance of resistance may have contributed to resistance. These results suggest that improvements in resistance management and a more integrated approach to the use of Bt crops may be necessary.
Saturday, July 23, 2011
Genetically modified crops safety assessments
By Gilles-Eric Séralini, Robin Mesnage, Emilie Clair, Steeve Gress, Joël Spiroux de Vendômois, Dominique Cellier
Environmental Sciences Europe
Purpose: We reviewed 19 studies of mammals fed with commercialized genetically modified soybean and maize which represent, per trait and plant, more than 80% of all environmental genetically modified organisms (GMOs) cultivated on a large scale, after they were modified to tolerate or produce a pesticide. We have also obtained the raw data of 90-day-long rat tests following court actions or official requests. The data obtained include biochemical blood and urine parameters of mammals eating GMOs with numerous organ weights and histopathology findings.
Methods: We have thoroughly reviewed these tests from a statistical and a biological point of view. Some of these tests used controversial protocols which are discussed and statistically significant results that were considered as not being biologically meaningful by regulatory authorities, thus raising the question of their interpretations.
Results: Several convergent data appear to indicate liver and kidney problems as end points of GMO diet effects in the above-mentioned experiments. This was confirmed by our meta-analysis of all the in vivo studies published, which revealed that the kidneys were particularly affected, concentrating 43.5% of all disrupted parameters in males, whereas the liver was more specifically disrupted in females (30.8% of all disrupted parameters).
Conclusions: The 90-day-long tests are insufficient to evaluate chronic toxicity, and the signs highlighted in the kidneys and livers could be the onset of chronic diseases. However, no minimal length for the tests is yet obligatory for any of the GMOs cultivated on a large scale, and this is socially unacceptable in terms of consumer health protection. We are suggesting that the studies should be improved and prolonged, as well as being made compulsory, and that the sexual hormones should be assessed too, and moreover, reproductive and multigenerational studies ought to be conducted too.