Maize MON Research Articles

5'-Nuclease PCR for quantitative event-specific detection of the genetically modified Mon810 MaisGard maize

Genetically modified maize is grown extensively in the world today. MaisGard (Monsanto, Yieldgard in the USA) is a genetically modified maize harbouring the Mon810 transformation event. European Community legislation requires that genetically modified organisms (GMOs) be approved before they are placed on the market. Labelling is required when more than 1% of any ingredient of a food originates from a GMO. There is consequently a need for specific, quantitative methods for detection of genetically modified foods. We have determined the DNA sequence of the 5'-flanking region of the Mon810 insert using ligation mediated PCR. A primer probe set overlapping the junction was designed and used in a quantitative, event-specific Taqman 5'-nuclease assay. Mon810 DNA was quantified relative to endogenous maize zein gene DNA. The results were expressed as the percentage of genetically modified Mon810 maize DNA relative to the total content of maize DNA.

Cortical connections of the primary somatosensory cortex and cortical taste area in rats

The EU legislation requests post-market environmental monitoring (PMEM) of a genetically modified (GM) organism even if its pre-market risk assessment indicated negligible risks. It has been claimed that the monitoring of the only currently commercially cultivated GM plant in the EU, Bt MON810 maize, has not revealed any adverse effects. However, the implementation of its PMEM has been criticised repeatedly by the European Food Safety Authority (EFSA).Although EFSA agreed with the monitoring plan consisting of four tools, as proposed by the company which markets MON810, in practice PMEM has relied on famers’ questionnaires, a farmers’ complaint system, and a literature survey. The fourth approach, environmental surveillance networks, has not been utilised yet. Furthermore, PMEM requires that farmers plant a refuge of non-Bt maize in order to sustain the efficiency of the plant in combating the targeted pest.This paper aims to contribute to improved PMEM by means of a critical evaluation of its implementation in the Czech Republic based on interviews and a questionnaire survey of farmers who cultivated MON810. The results indicate that a quarter of the farmers who were surveyed did not comply with the refuge requirement. Moreover, farmers often lacked the knowledge, time, and motivation to observe and report the potential impacts of Bt maize on biodiversity, which is supposed to be monitored by the PMEM farmers’ questionnaire.The findings of this study compound the previous criticism and suggest that the current practice of PMEM limits its aim of detecting unanticipated adverse effects of MON810 maize cultivation on human and animal health and the environment. The PMEM plan should be revised before the approval process of the application for the renewal of the authorisation for MON810 cultivation in the EU continues.

Preventing insect adaptation to insect-resistant crops: are seed mixtures or refugia the best strategy?

Transgenic crops expressing insecticidal toxins could soon provide safe, clean and effective means of pest control, but their usefulness will be short-lived if insects adapt to the toxins. Two planting strategies are among those that have been recommended to delay crop failure: susceptible insects could be conserved by planting either ‘refugia’, i.e. separate fields of toxic and toxin-free crop, or ‘seed mixtures’ of toxic and toxin-free plants in the same fields. However, we show that if insects can move from plant to plant, seed mixtures may actually hasten insect resistance compared with pure stands of toxic plants. Insect movement causes an increase in effective genetic dominance which can counteract reduced selection due to the mixture. This failure of seed mixtures is likely under just those conditions, low genetic dominance of resistance, which predict a good chance for resistance to the toxin to evolve slowly. Seed mixtures, unlike refugia, are therefore failure prone. This result also suggests potential problems with a third strategy, tissue-specific expression of toxins, which essentially provides a mixture of toxin-free and toxin-containing tissues on the same plant. However, better information and modelling are urgently required to evaluate alternative means of slowing insect adaptation to resistant crop plants. Legislation for toxinfree refugia may provide one of the best available means for conserving insect susceptibility.