Today in AgBioView from www.agbioworld.org: January 13, 2006
* Genetically modified mush
* STATEMENT ON THE EFFECT OF GM SOYA ON NEWBORN RATS
* EU Authorizes Three Types of Biotech Corn
* Global Status of Commercialized Biotech/GM Crops: 2005
* Genetically modified papaya, rice, abaca now in the pipeline
* Politics stalling Kenya's biotechnology policy
* GM cropland in developing nations grows by a quarter
* South Africa 8th among mega-growers of GM crops
* Philippines' gm crop areas surge 40% in 2005
* India: Bt cotton blooms all over
* Papaya farmers rally for end to ban on GMO field trials
* India tops in GM acreage growth
* European GMO labeling thresholds impractical and unscientific
Genetically modified mush
- NATURE BIOTECHNOLOGY 24, 2 (2006)
It is not often that field peas capture national headlines. But that is exactly what occurred late in November when researchers at Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) published a paper describing changes in the structure and immunogenicity of a common bean protein after transgenic-expression in peas. Contrary to media reports, the paper did not provide definitive evidence that the transgenic protein was allergenic in humans. Nor were the changes in protein structure particularly shocking or surprising. What was shocking, however, was the political fallout following the study's announcement.
The field pea is big business in Australia. Each year, the annual harvest brings in around AU$120 ($88) million. Infestations of the pea weevil (Bruchus pisorum) remain a problem, however, reducing pea yield, compromising product quality and causing significant economic losses. In the early 1990s, the high economic and environmental costs of controlling weevils by chemical pesticides prompted T.J. Higgins of CSIRO and Maarten Chrispeels of the University of California, San Diego, to collaborate on a project to create a transgenic pea (Pisum sativum) that produces alpha-amylase inhibitor 1, a protein with insecticidal properties originally isolated from the common bean (Phaseolus vulgaris) that is normally absent in peas.
This protein inhibitor works by suppressing the activity of pea weevil alpha-amylase, an enzyme required by the insect to digest starch in pea cotyledons. Weevils that feed on peas expressing the inhibitor essentially starve to death. In six field trials between 1996 and 2001, peas expressing amylase inhibitor not only achieved yields comparable to nontransgenic peas but also demonstrated a remarkable (99.5%) level of resistance to weevils.
Against this promising background and as part of its risk assessment, the CSIRO team sought to establish whether there were any differences in immune responses elicited in BALB/c mice exposed to the pea form of the alpha-amylase inhibitor or the native form in beans. Unlike mice fed on a diet of wild-type peas (lacking the alpha-amylase inhibitor) or bean (containing the native inhibitor), animals that had previously ingested transgenic peas exhibited elevated levels of antigen-specific IgG1 in serum, enhanced delayed-type hypersensitivity responses in skin and increased reactivity to other food antigens.
The results convincingly demonstrate that oral ingestion of the transgenic amylase inhibitor in peas induces a CD4+ T-helper cell type 2 (Th2) inflammatory response in mice that is absent in animals fed on beans. Altered antigenicity correlates with differences in glycosylation and/or other post-translational modifications at the same residues within the inhibitor. On the basis of these data, CSIRO discontinued the program.
That is about as much as can be said. Although Th2 responses are commonly associated with allergic responses, the failure to measure antigen-specific IgE (the immunoglobulin indicative of allergy) precludes a definitive conclusion. We do not know whether immunogenicity equates to allergenicity. We do not know whether BALB/c mice immune responses are analogous to allergic responses in humans. And we do not know whether the concentration of amylase inhibitor in peas (4% of total protein) was similar to that in beans. This last point is important as the abundance of a protein can strongly influence its allergenicity.
Although alpha-amylase inhibitors from legumes are not known to cause allergies, those found in cereals belong to the prolamine superfamily of proteins that is well represented in lists of known allergens. Many of these are small, sulfur-rich seed proteins that also include the 2S albumin protein from Brazil nuts (Bertholletia excelsa). If 2S albumin sounds familiar, that is because soybeans expressing the very same protein remain the only documented example of a transgenic crop discontinued because of evidence of a risk of allergenicity.
The key question is whether the transgenic pea protein would have been flagged by current internationally recognized Codex Alimentarius Commission (CODEX) food standards. The answer appears to be yes. Such assessments are based on sequence homology to known allergens or serum IgE screening with sera from patients allergic to the source of the gene (or sources showing significant homology). A search of a database of known allergens (http://www.allergenonline.com/) reveals limited amino acid sequence identity (approx35-39%) between the P. vulgaris alpha-amylase inhibitor and minor allergens of peanut and soybean. As the inhibitor is resistant to pepsin hydrolysis (another hallmark of allergens), it thus seems very unlikely that the protein would have sailed through the CODEX process.
All this would probably be a scientific sidenote if it weren't for the fact that a senior Western Australian official took it upon himself to use the pea study as pretext to go on the offensive against genetically modified (GM) food. No sooner had CSIRO released its results than Minister of Agriculture Kim Chance announced the setting up of an "independent study" to review the possibility that "when a gene is taken out of one organism and put into another, the protein expressed in that gene may be different." The study was needed, Chance said, to investigate the propensity of rats fed Bt transgenic corn to develop "cancerous and pre-cancerous growths" and the potential of "GM DNA to enter animal bodies." A few days later, the Western Australian newspaper reported that Chance had awarded the funding for the study to the Institute for Health and Environmental Research in Adelaide (http://www.iher.org.au/). This institute consists of three people with no scientific expertise in long-term feeding studies and a clear agenda against anything remotely connected to a transgene. So much for an independent study.
Chance is entitled to his opinion. But the day must come when he, and politicians like him, realize that absolute proof for the safety of GM (or any other) food is a scientific impossibility. We have in place a reliable assessment process to flag potentially allergenic recombinant proteins on a case-by-case basis. And with so many other priorities competing for taxpayer money, one must question whether the best interests of the Western Australian public have really been served.
STATEMENT ON THE EFFECT OF GM SOYA ON NEWBORN RATS
- Advisory Committee on Novel Foods and Processes, 5 December 2005
The Committee has examined a report provided to it by Dr Irina Ermakova containing preliminary results from a study of genetically modified (herbicide-tolerant) soya that was conducted in Russia. The report described reduced growth and increased mortality amongst pups born to rats given soya flour from GM soya beans, when compared with those born to rats given non-GM soya flour or a control group given no soya. The report lacks detail essential to meaningful assessment of the results. In particular, it does not provide key information concerning the composition and nutritional adequacy of the test diets. Also, the Committee notes that these are preliminary results; the study has not been quality-controlled through the normal peer review process preceding scientific publication.
It is well known that rodents fed large quantities of raw soya will suffer various nutrient imbalances that cause reduced growth rates and other adverse effects. This would be expected whether the soya beans are from a GM or non-GM source. It is also well known that protein quality varies between varieties and geographical origins of soya, independently of whether they have been genetically modified. It is therefore essential to ensure that diets which contain a high proportion of different types of soya are carefully balanced and equivalent in terms of nutrients and anti-nutritional components. It is not known whether this was done in the present study.
Unusually, the soya flour was given to the animals alongside conventional feed pellets rather than incorporated into the feed. The mothers received up to 20g of soya flour per day during the study, which could have displaced a significant quantity of the conventional feed pellets which normally assure optimum vitamin and mineral intake. The quantities of soya consumed by each animal are not known and there are no data on the consumption of the conventional feed. Neither were any data on cause of death provided. The GM and non-GM soya samples were obtained from different sources and there is no information on the presence of potential contaminants, such as mycotoxins, resulting from contamination during transportation and storage.
In conclusion, there are a number of possible explanations for the results obtained in this preliminary study, apart from the GM and non-GM origin of the test materials. Without information on a range of important factors conclusions cannot be drawn from this work. The Committee Secretariat is contacting Dr Ermakova to obtain further information on this study and the Committee will consider any further information that can be obtained and review the position if a full report of the study is published in the peer-reviewed literature.
The Committee also notes that Dr Ermakova’s findings are not consistent with those described in a peer-reviewed paper published in 2004.1 In a well controlled study no adverse effects were found in mice fed on diets containing 21% GM herbicide-resistant soya beans and followed through up to 4 generations.
EU Authorizes Three Types of Biotech Corn
- Associated Press, Jan 13, 06
All Associated Press NewsBRUSSELS, Belgium (AP) - The European Commission on Friday cleared three types of genetically modified corn made by the U.S. biotech products maker Monsanto Co. for use in the European Union.
Two types of corn will be used for food and food ingredients and the third mainly will be used for animal feed, the commission said. The three corn types and any products containing them will have to clearly indicate that they have been genetically modified.
ISAAA Briefs 34-2005: Global Status of Commercialized Biotech/GM Crops: 2005
ISAAA Press Release
Global Area of Biotech Crops, 1996 to 2005
Global Area of Biotech Crops, 1996 to 2005: Industrial and Developing Countries
Global Area of Biotech Crops, 1996 to 2005: by Country
21 Biotech Crop Countries and Mega-Countries, 2005
Global Area of Biotech Crops, 1996 to 2005: by Crop
Global Area of Biotech Crops, 1996 to 2005: by Trait
Global Adoption Rates (%) for Principal Biotech Crops
Genetically modified papaya, rice, abaca now in the pipeline
- Business World (Philippines), January 12, 2006
Amid global developments in the use of biotechnology in crops, the development of genetically engineered papaya, rice, eggplant, and abaca will soon add to the current commercialized use of genetically modified corn.
National Academy of Science and Technology president Dr. Emil Q. Javier said that some of the biotechnology projects in the pipeline include the development of a delayed-ripening papaya, ringspot virus-resistant papaya, GMO rice, the infusion of Bt genes in eggplant and the development of disease-resistant abaca.
Dr. Randy Hautea of the International Service for the Acquisition of Agri-Biotech Applications (ISAAA) said that genetically altered papaya may be commercially produced in about three years. He said GMO papaya is ready for field trials. Required field testings will take at least one year to ensure the product is safe for consumption.
Mr. Javier said infusion of delayed-ripening genes in papaya aims to extend the shelf life of the fruit.
Ringspot virus, on the other hand, is a disease that had ravaged Hawaii's papaya farms, he explained. The Philippines, said Mr. Javier, has started transferring the technology that Hawaii used to fix its ringspot virus problem since 1997.
Three genetically altered traits for rice are also in the offing, said Mr. Javier. Philippine Rice Research Institute (PhilRice) is in the process of developing insect-resistant rice, bacterial blight disease-resistant rice, and so-called "golden" rice or the vitamin-enriched rice.
Amid meager funding for rice research in the country, PhilRice director Leo S. Sebastian had said in an earlier interview that the government is looking at commercial production of GMO rice in about five years.
Mr. Javier also said breeders from the University of the Philippines Los Banos and the Fiber Industry Development Authority are trying to infuse genes that make abaca resistant to the "mosaic" and "bunchy top" disease. "This disease is really affecting the abaca industry and the solution lies in the infusion of disease-resistant genes," said Mr. Javier.
ISAAA's annual review in 2005 of the global status of commercialized biotech crops shows that the area used for biotech crops in the Philippines reached 65,000 hectares in 2005, or a 40% increase from 2004. Worldwide, such area has reached 90 million hectares, increasing 11% from 2004.
Politics stalling Kenya's biotechnology policy
- African News Dimension, 12 January 2006, By Kimani Chege
The director of Kenya plant health Inspectorate (KEPHIS) and other biotechnology stakeholders have blamed national politics for delaying implementation of biotechnology rules.
Kenya biotechnology regulators have admitted that their urge to develop policy to regulate the industry in the country were slowed down by national politics.
The Kenya Plant Health Inspectorate Services (KEPHIS) director Dr. Kedera Chagema has noted that efforts to draw a national biotechnology policy and bill were abandoned when the country went on a campaign trail to vote for a national constitution.
He said the policy document remains a critical issue in the biotechnology industry that he says operates through a set of regulations developed as temporary measures and was even affecting other issues like food donation to the country.
" People ask me all the time, which laws are we using to control imports. I find myself giving the old tired answer, that the bill is coming soon," lamented Dr. Chagema.
However the chairman of the Africa Biotechnology Stakeholders Forum (ABSF), Prof Norah Olembo noted that the final draft of the policy document is expected to ready by the end of the month, and later presented to the cabinet for approval.
She however noted that a bill to stipulate offences for wrong genetic engineering use will be subjected to public and parliament debate later in the year.
They were speaking during the launch of a global report on the status of commercialised biotechnology developed by the International Service for the Acquisition of Agribiotech Applications (ISAAA).
The regulations being governed by the Kenya National council of Science and Tecghnology, only allow the development of genetically modified crops on for testing and prohibits commercialisation.
GM cropland in developing nations grows by a quarter
Soybeans account for 60 per cent of the area planted with GM crops
- SciDev.Net, by Marina Lemle, 13 January 2006
[RIO DE JANEIRO] The area in developing countries that is planted with genetically modified (GM) crops increased by nearly a quarter between 2004 and 2005.
Brazil saw the largest increase and now accounts for ten per cent of global GM crop production.
The figures are in the latest annual report of the International Service for the Acquisition of Agri-biotech Applications (ISAAA), released on 11 January.
The report shows the area of Brazil under GM crops nearly doubled last year, from five million hectares to 9.4 million.
Although GM crops have been grown in the country for some years, the dramatic increase follows the enactment, in March 2005, of a law allowing such crops to be planted and sold (see Brazil says 'yes' to GM crops and stem cell research).
After Brazil, GM farming increased most in the United States, Argentina and India, which had the greatest proportional increase — from 500,000 hectares planted with GM crops in 2004, to 1.3 million hectares last year.
The report says that in 2005, developing countries accounted for more than a third of the global area planted with GM crops. And between 2004 and 2005, growth in GM cropland was substantially higher in these countries than in industrialised ones (23 per cent, compared to just five per cent).
"Notably, 90 per cent of the beneficiaries were resource-poor farmers from developing countries", said ISAAA president Clive James in a conference call with Brazilian journalists.
"In 2005, approximately 7.7 million poor subsistence farmers benefited from GM crops, 6.4 million in China, a million in India and thousands in South Africa," he added.
The day before the ISAAA released its figures, the environmental group Friends of the Earth published a 100-page report called Who benefits from GM crops?
This questions the safety of GM crops and the role they would play in solving world hunger, and concludes that the spread of GM crops in a limited number of countries is because of aggressive strategies of the biotech industry.
South Africa 8th among mega-growers of GM crops
- Angola Press, January 13, 2006
Johannesburg, South Africa, 01/13 - Genetically modified (GM) crops surged globally in 2005, with South Africa ranking eight amongst the mega-countries growing the crop, a global report on Biotec Crops released here Thursday indicated.
According to an International Service for the Acquisition of Agri-Biotech Applications (ISAAA) report, South Africa and the 14 mega-countries grew 50,000 hectares, or more, of GM crops.
Other developing countries that have achieved mega-status include Paraguay, India, Mexico and the Philippines.
"South Africa has tested GM varieties since 1990, approved commercial release in 1997 and in 2004 grew some 520,000 hectares of GM maize, cotton and soybeans," said ISAAA chairman Clive James, who is also author of the report.
James said some 8.5 million farmers in 21 countries on all six continents grew 90 million hectares of GM crops in 2005, compared to 81 million hectares grown in 17 countries in 2004.
"GM crops are not just for large-scale commercial farmers, on the contrary, some 90 percent of the 8.5 million farmers that benefit from GM crops are resource-poor, small-scale farmers in developing countries. Most of these farmers, 6.4 million, are in China where they planted 3.3 million hectares of Bt cotton," the report says.
James said the importance of this technology for developing countries is also evident from the 17.1 million hectares of GM soybeans, cotton and maize grown in Argentina (second after the US), and Brazil with 9.4 million hectares of GM soybeans (almost double their 2004 hectares).
According to the study, herbicide tolerant soybeans remain the major GM crop with 60 percent of global GM area, followed by maize with 24 percent, cotton 11 percent and canola with 5 percent.
In Africa most countries are reported to be putting biosafety laws in place, while field trials with GM crops are under way in Zimbabwe, Kenya, Burkina Faso and Egypt, with several others expected to start soon.
Philippines' gm crop areas surge 40% in 2005
- Frash Plaza, Jan 13, 2006
Areas planted to genetically modified (GM) plants in the Philippines grew by 40 per cent last year, signifying Filipinos' acceptance for biotech crops, the International Service for the Acquisition of Agri-biotech Applications (ISAAA) 2005 executive report bared.
"This unprecedented high adoption rate reflects the trust and confidence of millions of farmers in crop biotechnology," Randy Hautea, global coordinator of the ISAAA told media during the launch of the ISAAA 2005 executive report in Makati City.
Bacillus thuringiensis (Bt) corn plantation has expanded to 70,000 hectares, majority of which are in Region II, particularly in the provinces of Isabela and Cagayan, and South Cotabato in Mindanao.
The Philippines is the first country in Asia to plant Bt corn commercially. The government initially allowed 10,000 Filipino farmers to plant Bt corn in over 20,000 hectares in 2003. Since then, more farmers have gone into the production of GM crops which increased their produce twice.
There are 17 transformation events (TEs) of genetically modified (GM) crops for commercial use approved by the Bureau of Plant Industry (BPI) for food, feed or processing materials.
This includes major crops such as corn, rice, soybean, canola, potato and cotton, tomato, eggplant, and abaca, one of the most important fiber that only the Philippines and Ecuador manufacture.
Currently, the University of the Philippines in Los Banos (UPLB) is field testing its papaya resistant to ringspot virus variety, which is hoped to be commercially available in the next three years.
"Medical biotech had been around for ages, we can't find any reason why some would not accept biotech crops. These crops underwent thorough research and testing. It's proven safe," said National Academy of Science and Technology (NAST) president Dr. Emil Javier.
"We are not taking any shortcuts. The NAST is calling for responsible use of biotech crops," he added. The report bared that global value of biotech crop market projected at US$ 5.5 billion in 2006, an increase from US$5.25 billion in 2005.
GM soybean also continued to be the principal biotech crop worldwide last year, occupying 54.4 million hectares (60 per cent of global biotech area), followed by maize (21.2 million hectares at 24 per cent), cotton (9.8 million hectares at 11 per cent) and canola (4.6 million hectares at 5 per cent of global biotech crop area).
In 2005, herbicide tolerance deployed in soybean, maize, canola and cotton continued to be the most dominant trait occupying 71 per cent or 63.7 million hectares, followed by Bt insect resistance at 6.2 million hectares (18 per cent) and 10.1 million hectares (11 per cent) to the stacked genes.
The latter was the fastest growing trait group between 2004 and 2005 at 49 per cent growth, compared with nine per cent for herbicide tolerance and four per cent for insect resistance.
Countries who are now planting GM crops are USA, Argentina, Brazil, Canada, China, Paraguay, India, South Africa, Uruguay, Australia, Mexico, Romania, the Philippines, Spain, Colombia, Iran, Honduras, Portugal, Germany, France and the Czech Republic.
India: Bt cotton blooms all over
- Fibre 2 Fashin, January 13, 2006
Bt cotton production likely to grow as the area under cultivation of genetically modified Bt cotton in 2005-06 (October-September) increased by 160 percent up from 500000 hectares to estimated 1.3 million hectares, says International Service for the Acquisition of Agri-biotech Applications (ISAAA).
India has also a reason to be happy as more than 15.6 percent area has been brought under the cultivation from total 9 million hectares in India, said Bhagirath Choudhary, ISAAA head based in India.
Four companies have already introduced about 20 Bt cotton hybrid in Indian markets and more than 25 companies are in process of developing new breeds, informed Choudhary.
Recording a three-fold increase over 2004, more than 1 million small and marginal cotton growers planted Bt cotton in 2005, added Choudhary.
Papaya farmers rally for end to ban on GMO field trials
- Bangkok Post, By PIYAPORN WONGRUANG, Jan 13, 2006
About 100 papaya growers whose crops suffer from a papaya disease outbreak rallied at the Ministry of Agriculture and Cooperatives yesterday to call for an end to the ban on field trials of genetically-modified crops.
Niwat Pakwiset, a farmer, said papaya orchards in the Central provinces including Ratchaburi and Rangsit were badly hit by the ringspot virus, which would lead to a sharp decrease in papaya produce.
The farmers hoped that GM papaya would be a solution for the problem as some scientists claimed the strain was resistant to the ringspot virus, he said.
"The field trial of GM papaya will let us know whether the strain is good or bad," said Mr Niwat, saying the group was acting on its own behalf, without help from outside organisations. Multinational agribusiness firms have been pressing the government to approve commercial plantations of GM crops here.
The government has stood against the growing of GMOs and imposes a ban on open field trials of transgenic crops in 1999, after finding that GM cotton crops belonging to the US-based company Monsanto had spread to nearby farms growing non-GM crops. The ban is backed by some farmers and environmentalists, who fear the GM crops could hurt the environment and human health.
A state scientist in the field, however, said the trial was crucial as it would allow scientists to learn about consequences in the real environment.
The scientist, however, agreed that bio-safety measures should also be in place to ensure safety.
India tops in GM acreage growth
- Financial Express, Jan 12, 2006
NEW DELHI, JAN 12: Estimated area, in India, under Bt cotton cultivation has increased to 1.3 million hectare in 2005 as against 500,000 hectare in 2004, according to the annual review report of the US-based International Service for the Acquisition of Agri-biotech Application (ISAAA). This marks an increase of 160%, highest among 21 countries growing genetically modified (GM) crops.
India has so far approved only one GM crop ie Bt cotton for commercial cultivation.
India’s coverage under Bt cotton in 2005 is a miniscule part of the global area under GM crops, which is estimated at 90 million hectare. Countries like US, Argentina, Brazil, Canada, China and Paraguay have higher area coverage under GM crops. In US the area coverage is estimated at 49.8 million hectare, in Argentina it is 17.1 million hectare, in Brazil 9.4 million hectare, in Canada 5.8 million hectare and in Paraguay it is 1.8 million hectare.
Despite the low area coverage, India is considered among the 14 ‘mega biotech countries’. Out of the 14 ‘mega biotech countries’, South Africa, Uruguay, Australia, Mexico, Romania, Phillipines and Spain have lesser area coverage under GM crops. Colombia, Iran, Honduras, Portugal, Germany, France, and Czech Republic which have less than 0.1 million hectare coverage are not designated as mega biotech countries.
In his recorded speech played before the media, the ISAAA chair Clive James said that France and Portugal resumed cultivation of Bt maize and Czech Republic has approved Bt maize for the first time.
Speaking from Phillipines, the ISAAA Asia coordinator, Dr Randy Hautea said that Indonesia and Bulgaria which suspended GM crop cultivation in 2004 have now granted permission for sowing biotech crops.
European GMO labeling thresholds impractical and unscientific
- NATURE BIOTECHNOLOGY 24, 23-25 (2006), By Florian Weighardt
via Milano 1095, 21027 Ispra (VA), Italy. email@example.com
To the editor:
In the next few months, the European Union (EU) will witness a burst of novel authorizations for genetically modified (GM) plants. In this context, a huge effort is underway in the laboratories of the European Commission (EC), of the Member States, of third countries and of private companies, to elaborate, assess and validate the necessary sampling strategies and molecular analytical procedures required to implement European regulatory requirements1 for labeling food and feed products containing ingredients from GM organisms (GMOs). It is now three years since the legislation was first introduced, yet enormous technical and scientific challenges remain in reducing regulations to practice.
The EC first introduced labeling thresholds for the accidental unavoidable presence of GM ingredients because of the technical and practical impossibility of ensuring their absolute absence in food or feed2, 3, 4. The latest regulation fixes the labeling threshold as follows: "... foods containing material which contains, consists of or is produced from GMOs in a proportion no higher than 0.9% of the food ingredients considered individually or food consisting of a single ingredient, provided that this presence is adventitious or technically unavoidable"4. The term GMO is defined by article 2(2) of Directive 2001/18/EC5 as follows: "'GMO' means an organism, with the exception of human beings, in which the genetic material has been altered in a way that does not occur naturally by mating and/or natural recombination." Finally, ingredient is defined by the article 4(a) of the Directive 2000/13/EC as "...any substance, including additives, used in the manufacture or preparation of a foodstuff and still present in the finished product, even if in altered form"6. From the practical point of view, in the field of GM plants, the ingredient is the part of the organism directly employed or further transformed to be used as food or feed (e.g., maize kernels or soybean beans).
The first question facing a scientist attempting to develop an assay to implement the GMO regulations is: what does "0.9% of the food ingredients" mean in terms of genes? Or, put another way, how to translate the gross generic definition of "ingredient" into something making sense at the molecular level?
Currently, the method of choice for transgenic sequence detection is real-time PCR. In this approach, PCR is used to amplify a GM line-specific marker sequence and the results are quantified with respect to the amplified level of an endogenous sequence specific for the whole ingredient, termed a reference gene or 'normalizer.' The normalizer is usually a gene or a sequence marker within a gene that is species specific, well conserved and present at the same copy number among different lines of the same species.
In practice, certified reference materials (CRMs) are mandated in the European regulations for use in calibrating GMO quantification systems7, 8, 9, 10. CRMs are prepared from certified seeds of the GM inbred line and of the non-GM parental variety used for the transformation are homogenized and grinded to powder.Subsequently, the resulting GM and non-GM flours are blended on a gravimetrical weight/weight basis following strict certified procedures. Different concentration levels are prepared to obtain the so-called CRM series. Genomic DNA can be extracted from these materials to be used as a calibrator in real-time PCR.
Defining the relative GMO content in a product on the basis of the weight/weight ratio of raw materials (ingredients) should imply the assumption that a conserved direct proportionality is found between the weight of the ingredient and the total number of genes or genomes contained in it. Unfortunately, such proportionality doesn't exist in reality7, 8, 10. As a consequence, the true molecular dosage of GM sequences can vary in an analyzed ingredient sample (or in a CRM) with respect to the nominal GM content defined as stipulated by current regulations. This ingredient versus gene dosage ratio has four main sources of variation.
First, no data are available on whether different lines of the same plant species exhibit a conserved ratio between the weight of what is considered an ingredient and the number of genomes contained in it8. Even when considering the same line, it is conceivable that factors influencing plant growth like zonal and/or weather conditions could cause a significant drifting of this ratio among different batches. In addition, the generalized little availability of certified GMO material and of its parental organism material makes it difficult to investigate this possible source of variability9. As an example, the certification document10 for the Monsanto's (St. Louis, MO, USA) Roundup-Ready soybean reference material series 410-S issued by the Institute for Reference Materials and Measurements (IRMM; Geel, Belgium) of the Joint Research Center clearly states "...the ratio GMO-DNA/non-GMO-DNA reference materials may significantly deviate from the certified powder mass ratio values." Moreover, the same document also notes "one has to be careful to draw quantitative conclusions from measurements of unknown samples as DNA and/or protein based GM quantification may depend on varieties." The same two statements are repeated in other GMO-CRM certification documents (http://www.erm-crm.org).
Second, it is well known that some species of cultivated plants, like maize (Zea mays), show significant intraspecies variation in nuclear DNA content. In maize, several sources of variability have been described, such as the location from which lines originate, environmental factors, growth parameters and yield parameters11, 12, 13, 14. As a consequence, it is not possible to establish one single defined DNA C-value for all maize lines. Laurie & Bennett15 estimate that the C-value of DNA from different maize lines ranges from about 2.364 Mb (2.45 pg) to about 3.233 Mb (3.35 pg). This high genetic plasticity of plant genomes doesn't represent a real problem if real-time PCR is used for the analysis and as long as the copy number of employed reference genes (normalizers) remains constant among the different lines. On the other hand, it becomes necessary to check the reference gene copy number in all lines employed in agriculture.
Third, if we consider diploid organisms, both the genetic modification and the species-specific reference marker could be found in homozygosis or in heterozygosis. As a consequence, the ratio between the genetic modification and the normalizer could be 1:1, 1:2 or 2:1. Usually, GM lines are self-pollinated to obtain homozygous lines (inbred lines) for the novel trait8. On the other hand, in common agricultural practice, inbred lines are crossed with specific selected non-GM lines to obtain hybrids. What's more, different hybrids of the same GM event are often raised for the use in different geographic/climatic situations. As a result, the ratio between the GM-specific marker and the species-specific reference gene could vary significantly from lot to lot.
Finally, the ploidy of the tissue that the ingredient is derived from could vary from the usual diploid asset of organisms. Several cultivated hybrid plants are tetraploid or polyploid8. In addition, the endosperm of seeds, composed mostly of starch-containing cells, is a triploid tissue arising from the fusion of a sperm nucleus with two polar nuclei of the egg cell. In some seeds, for example in maize, the endosperm persists as a storage tissue and is used to nourish the germinating seedling16. These facts, along with what is described in the previous point enhances the degrees of variability of the ratio between the GM trait and the species-specific normalizer.
If one strictly follows the definition of "GMO ingredient" as stipulated by current European regulations, there is no difference between, for example, an inbred diploid line being homozygous for the genetic modification, a diploid line being heterozygous for the modification and a tetraploid line with only one modification per genome: they are formally all full GM ingredients (that is, 100% GMOs). On the other hand, from an analytical point of view, a homozygous diploid, heterozygous diploid and tetraploid line with only one modification exhibit 100%, 50% and 25% GMO content, respectively. This situation is worsened if we consider a marketed product ingredient resulting from the randomized mixture of different lots and lines of the same species depicting different genomic assets in terms of zygosis, ploidy and C-value. In this case, it is impossible to determine each component's specific contribution and molecular analytical tools will necessarily over- or underestimate the nominal GM component of the product ingredient. De facto, the quantification of the GM content in a sample provides us with neither the true molecular dosage of the modification(s) (e.g., the number of modified haploid genomes versus the total number of haploid genomes) nor the content defined on the basis of European regulations; instead, it gives us a relative gene dosage determined with respect to the employed CRM.
Taken together, these problems create an unclear environment in which the regulations are unenforceable using the molecular analytical tools available. Every analytical result could potentially be invalidated by means of scientific data demonstrating that the CRMs used are not representative for the samples under analysis. The EU legislators continue to fudge; the current regulation 1829/2003 (ref. 4) uses the same imprecise 1% threshold as its predecessor 49/2000 (ref. 2). And the EC's most recent recommendation (2004/787/2000)17 only partly solves the problem by defining the percentage of GM DNA as "the percentage of GM-DNA copy numbers in relation to target taxon specific DNA copy numbers calculated in terms of haploid genomes."
Three years after the current EC regulation4 was issued, all the operative structures described within it (that is, the European Food Safety Agency and the Community Reference Laboratory) are now fully active. Yet, only two novel authorizations were granted in 2004 (Bt11 sweet corn and NK603 maize). All the other 25 GM plants, which are listed as authorized in the Community Register of GM Food and Feed (http://europa.eu.int/comm/food/dyna/gm_register/index_en.cfm), were placed on the market in the EC before the entry into force of the current regulation.
European legislations must move quickly to amend the current regulation so that rules provide an exact and scientifically acceptable definition of GMO content that can be adopted in testing. It is not a question of moving the regulatory goal posts; the current legislation doesn't even tell us where to put the goal posts.
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