The development of transgenic crops as production platforms for biogenic agents will largely depend on the success of efforts to confine the genes and their expressed proteins in field environments. We have used quantitative exposure assessment to evaluate how management practices affect materials escape due to outcrossing by pollen flow or grain loss during harvest operations. Specifically, we study the use of maize to produce biogenic agents within field-confined systems. Decision trees representing simplified schemes of fully conforming (designed to comply with current regulatory standards for field confined trials), partially conforming, and non-conforming management practices were developed. Exemplifying assumptions and published data for conformance and material fate probabilities were used in Monte Carlo simulations to forecast materials escape by pollen outcrossing and harvest operations from a 1 ha source field. Deterministic analyses showed fully conforming confinement management restricted materials loss to low levels (for this example, outcrossing produced <1 in 106 kernels in receptor fields). The corresponding high-end (90th percentile) probabilistic result was 16- and 4333-fold higher (relative to deterministic outcrossing = 1) for outcrossing and harvest loss, respectively. For partially conforming practice, high-end outcrossing ranged from 100- to >15 000-fold over the base result in receptor fields, and harvest loss was >10 000-fold over the base result. For non-conforming practice, high-end outcrossing produced >15 000-fold greater kernels in receptor fields and high-end harvest loss was at least 19 000-fold greater. Deterministic estimates of off-field loss by machine transfer are as much as 30 000-fold higher for non-conforming operations relative to the base case of pollen outcrossing. Better knowledge of failure frequencies for confinement management practices, improved physical models of materials flows, refined analysis of confinement loss probabilities using quantitative tools, and decision analysis to improve and audit management system performance are all needed to extend understanding of confinement integrity beyond the exemplifying case used here.

Public debate about the possible risk of genetically modified plants often concerns putative effects of pollen dispersal and out-crossing into conventional fields in the neighborhood of transgenic plants. Though Vitis vinifera (grapevine) is generally considered to be self-pollinating, it cannot be excluded that vertical gene transfer might occur. For monitoring pollen flow and out-crossing events, transgenic plants of Vitis vinifera cv. `Dornfelder' harboring the gus-int gene were planted in the center of a field experiment in Southwest Germany in 1999. The rate of pollen dispersal was determined by pollen traps placed at radial distances of 5–150 m from the pollen-donor plants, at 1.00 and 1.80 m above ground. Transgenic pollen was evaluated by GUS staining, and could clearly be distinguished from pollen originating from non-transgenic grapevine plants. Transgenic pollen was observed up to 150 m from the pollen donors. The rate of out-crossing was determined by sampling seeds of selected grapevines at a distance of 10 m to the pollen source, and of a sector at 20 m distance, respectively, followed by GUS analysis of seedlings. The average cross-pollination rate during the experiment (2002–2004) was 2.7% at a distance of 20 m. The results of this first pilot study present a good base for further assessment under the conditions of normal viticulture practice.

Different techniques to assess bacterial community structure and diversity were evaluated in silages prepared with four different maize cultivars, three conventional and one transgenic (cv. Tundra, event Bt-176). Plants were cultivated in the greenhouse and harvested after 30 days of growth. Silage samples were collected at successive times during fermentation and analyzed for bacterial counts and by various DNA-based fingerprinting techniques. Bacterial counts were similar between cultivars for the total culturable bacteria, sporeforming, and mesophilic and thermophilic lactic acid bacteria (LAB). Further analysis of the species composition of 388 LAB strains by intergenic transcribed spacer (ITS) PCR followed by sequencing of 16S rRNA gene did not reveal differences between cultivars. In contrast, molecular fingerprinting methods targeting whole bacterial communities, such as automated ribosomal intergenic spacers analysis (ARISA) and 16S rRNA gene length heterogeneity-PCR (LH-PCR), indicated that different maize silage batches or cultivars hosted different bacterial communities. Thus, ARISA and LH-PCR fingerprinting techniques offer a fast and sensitive method to compare bacterial communities, and to detect differences in silage bacterial communities.

Spatially isolating genetically modified (GM) maize fields from non-GM maize fields is a robust on-farm measure to keep the adventitious presence of GM material in the harvest of neighboring fields due to cross-fertilizations below the European labeling threshold of 0.9%. However, the implementation of mandatory and rigid isolation perimeters can affect the farmers' freedom of choice to grow GM maize on their fields if neighboring farmers do not concur with their respective cropping intentions and crop plans. To minimize the presence of non-GM maize within isolation perimeters implemented around GM maize fields, a method was developed for optimally allocating GM maize to a particular set of fields. Using a Geographic Information System dataset and Monte Carlo analyses, three scenarios were tested in a maize cultivation area with a low maize share in Flanders (Belgium). It was assumed that some farmers would act in collaboration by sharing the allocation of all their arable land for the cultivation of GM maize. From the large number of possible allocations of GM maize to any field of the shared pool of arable land, the best field combinations were selected. Compared to a random allocation of GM maize, the best field combinations made it possible to reduce spatial co-existence problems, since at least two times less non-GM maize fields and their corresponding farmers occurred within the implemented isolation perimeters. In the selected field sets, the mean field size was always larger than the mean field size of the common pool of arable land. These preliminary data confirm that the optimal allocation of GM maize over the landscape might theoretically be a valuable option to facilitate the implementation of rigid isolation perimeters imposed by law.


This study evaluates a survey about Swedish farmers' attitude towards genetically modified (GM) crops, and their perception concerning potential benefits and drawbacks that cropping of an insect resistant (IR) GM variety would involve. The questions were “tick a box” choices, included in a yearly omnibus survey sent to 1000 Swedish farmers (68% response rate). The results showed that a majority of the farmers were negative, although almost one third claimed to be neutral to GM crops. The farmers recognized several benefits both in terms of agricultural production and for the environment, but they were also highly concerned about the consumers' unwillingness to buy GM products. Farmers perceived an increase in yield, but nearly as many farmers thought that there would be no benefits with growing an IR GM crop. Several differences in hopes and concerns of the farmers surveyed were revealed when they were divided in positive, neutral and negative groups. Farmers negative to GM were more concerned than positive farmers about IR GM crops being dangerous for humans, livestock or other organisms to consume. GM-positive farmers seemed to be most concerned about potential problems with growing a marketable crop and expensive seeds, but saw a reduced health risk to the grower, due to less use of pesticides, as a possible benefit. The results among the GM-neutral farmers were in most cases closely related to the positive farmers' choices, implying that they believe that there are advantages with growing an IR GM crop, but also fear potential drawbacks. This general uncertainty about GM IR crops may prevent them from accepting the new technology.

It is emerging that benefits of new innovations in agricultural biotechnology may not be realised without appropriate biosafety regulatory mechanisms. The Kenyan regulatory experiences related to regulation of genetically engineered (GE) agricultural activities are explored to provide some basis for defining the challenges involved in biosafety regulation. The various shortcomings in the way the Kenyan biosafety process has been implemented are consistent with the way regulatory systems have been evolving in Africa. The proposed adoption of a “smart regulation” provides the basis for a learning process through which subsequent biotechnology policy initiatives can be improved.

Fine roots of forest trees form together with certain soil fungi symbiotic structures (ectomycorrhizas), where fungal hyphae are in intimate contact with plant cells. Due to root cell degeneration, plant DNA is released and could be taken up by the fungus. The possibility that horizontal gene transfer might result in a risk for the environment should be evaluated before a massive release of genetically engineered trees into nature occurs, even though only a few convincing examples of horizontal gene transfer are known. Transgenic poplars containing a construct of the Streptomyces hygroscopicus bar gene under the control of the Cochliobolus heterostrophus GPD (glyceraldehyde-3-phosphate dehydrogenase) promoter were generated by Agrobacterium-mediated transformation. The functionality of this construct in the ectomycorrhizal model fungus Amanita muscaria was previously verified by protoplast-based fungal transformation. 35 000 ectomycorrhizas, formed between transgenic poplars and non-transgenic A. muscaria hyphae, were isolated and transferred to selective agar plates. Putative herbicide-resistant fungal colonies were obtained after the first round of selection. However, none of these colonies survived a transfer onto fresh selection medium, nor did they contain the bar gene, indicating that no horizontal gene transfer from poplar to A. muscaria occurred during symbiosis under axenic conditions. However, since ectomycorrhizas are associated under natural conditions with viruses, bacteria and other fungi, these additional associations should be evaluated in future.

This article analyzes the development of notifications of genetically modified plants field trials in the European Union from 1991 to 2001, based on the data collected at the European level in the Summary Notification Information Format database. During this time period, a total of 1687 field trial notifications were received. The number of field trial notifications dropped by 76% between 1998 and 2001, mainly due to the de facto moratorium in place since 1999. Input traits (77%) dominated the field trial notifications during the last decade, while output traits were relevant in only 18% of all notifications, with a decreasing relevance during the last six years. In particular, field trial notifications on molecular farming were almost absent in the EU. Large companies focused their field trials on crops with a high grown area in the European Union and resistance traits, while public institutions showed interest in a large diversity of plants and traits. Finally, some conclusions on future impacts of the results of the study are drawn in this article.

Genetically modified organisms (GMOs), e.g. viral vectors, could threaten the environment if by their release they spread hazardous gene products. Even in contained use, to prevent adverse consequences, viral vectors carrying genes from mammals or humans should be especially scrutinized as to whether gene products that they synthesize could be hazardous in their new context. Examples of such potentially hazardous gene products (PHGPs) are: protein toxins, products of dominant alleles that have a role in hereditary diseases, gene products and sequences involved in genome rearrangements, gene products involved in immunomodulation or with an endocrine function, gene products involved in apoptosis, activated proto-oncogenes. For contained use of a GMO that carries a construct encoding a PHGP, the precautionary principle dictates that safety measures should be applied on a “worst case” basis, until the risks of the specific case have been assessed. The potential hazard of cloned genes can be estimated before empirical data on the actual GMO become available. Preliminary data may be used to focus hazard identification and risk assessment. Both predictive and empirical data may also help to identify what further information is needed to assess the risk of the GMO. A two-step approach, whereby a PHGP is evaluated for its conceptual dangers, then checked by data bank searches, is delineated here.

Due to the involvement of scientific, industrial, commercial and public sectors of society, the complexity of the issues concerning the safety of genetically modified organisms (GMOs) for the environment, agriculture, and human and animal health calls for a wide coverage of information. Accordingly, development of the field of biotechnology, along with concerns related to the fate of released GMOs, has led to a rapid development of tools for disseminating such information. As a result, there is a growing number of databases aimed at collecting and storing information related to GMOs. Most of the sites deal with information on environmental releases, field trials, transgenes and related sequences, regulations and legislation, risk assessment documents, and literature. Databases are mainly established and managed by scientific, national or international authorities, and are addressed towards scientists, government officials, policy makers, consumers, farmers, environmental groups and civil society representatives. This complexity can lead to an overlapping of information. The purpose of the present review is to analyse the relevant databases currently available on the web, providing comments on their vastly different information and on the structure of the sites pertaining to different users. A preliminary overview on the development of these sites during the last decade, at both the national and international level, is also provided.

Regulations 1829/2003/CE and 1830/2003/CE have allowed the placing on the European market of GM products in food and feed chains, and have defined their rules of traceability and labeling. For some supply chains, like for soy and its derived products that are used in the production of feed, manufacturers have to face both non-GM and GM production, although there are no labeling requirements for animal products derived from animals fed with GMOs. This study presents the strategies of stakeholders involved in the feed production chain to maintain concurrent production of compound feed with GM and non-GM soy products, by dealing with the coexistence between those two crops. The stakeholders include importers, traders, soy processors, feed processors and retailers. The study shows that many tools are in place to ensure and maintain the current coexistence. However, a profound harmonization of procedures and methods at a European level should be encouraged.

A procedure is presented for developing environmental risk hypotheses associated with thedeployment of forest trees genetically modified to have altered wood properties and forselecting non-target species to test these hypotheses. Altered-lignin Pinusradiata trees intended for use in New Zealand are used as a hypothetical casestudy to illustrate our approach. Firstly, environmental management goals (such as woodproduction, flood control or preservation of biodiversity) were identified and linked tothe forest attributes they require. Necessary conditions for each attribute were listedand appropriate assessment endpoints for them developed. For example, biological controlof pests may be one condition necessary for a forest to have healthy trees, and thediversity and abundance of natural enemy species in the forest could be an appropriateassessment endpoint for measuring this condition. A conceptual model describing therelationships between an altered-lignin GM pine tree and potentially affectedinvertebrates and micro-organisms in a plantation forest was used to develop a set of riskhypotheses describing how the GM trees might affect each assessment endpoint. Becausepurified lignin does not represent the properties it imparts to wood, maximum hazard dosetests with non-target organisms, as are used to inform toxin risk assessment, cannot beconducted. Alternative experiments, based on current knowledge of the responses oforganisms to lignin, must be designed. A screening method was adapted and applied to adatabase of invertebrate species known to inhabit New Zealand pine forests to identify andprioritize non-target invertebrate species that could be used as experimental subjects forexamining these hypotheses. The screening model and its application are presented, alongwith a set of recommendations for pre-release tests with GM pines and potentially affectedinvertebrates and micro-organisms.

Hybridization of Brassica napus L. (oilseed rape) and Raphanus raphanistrum L. (wild radish) has been demonstrated, and may be the first step towards introgression of transgenes in this wild relative. If wild radish were to display a new adaptive advantage by expressing the transgene, this could modify the ecological balance of species within the agro-ecosystem. To determine if transgenes remained stable in the hybrid, the frequency of herbicide resistance was studied over four advanced generations of hybrid progeny (G8 to G11) that were subjected to herbicide selection pressure. It is expected that hemizygous resistant plants containing an herbicide resistance transgene back-crossed to wild radish would have 50% resistant progeny. In each of the G8 to G11 generations, only 18% of the progeny from resistant plants were resistant. The chromosome complement of herbicide-susceptible progenies, analyzed at G9, was not different from that of wild populations of wild radish. Herbicide-resistant G9 progeny showed higher chromosome instability, and one third of the progeny contained a supernumerary chromosome. These results suggest that in the presence of herbicide selection pressure, the transgene for herbicide resistance would be maintained despite a lack of stabilized introgression. In the absence of selection, the frequency of resistance in the population is expected to decline.

Risk assessments of new insect-resistant crops will need to estimate the potential for increased weediness of wild crop relatives as a consequence of gene flow. When field experiments are precluded by containment concerns, simulation experiments can identify hazards or measure expected differences between GMOs and parental plants. To measure plant fitness consequences of wild plant protection from Bt-susceptible herbivores, we used topical sprays of bacterial Bacillus thuringiensis larvacide (Bt) on Brassica rapa. Spontaneous crosses between B. rapa and Bt cole crops cannot be precluded, especially if adoption of Bt varieties leads to high exposure. We compared survivorship and seed output of B. rapa that were either protected from or exposed to Bt-susceptible Lepidoptera in the various conditions where hybrids are likely to occur: cultivated (disked) soil, uncultivated agricultural field margins, and nearby non-crop habitats (meadows and ruderal areas). The relative effect of herbivore protection varied among years, habitats, and populations of seedlings. In 2003–2004, Bt sprays did not result in lower herbivory on B. rapa, and plant fitness was not increased. However, in 2004–2006 B. rapa seedlings protected from Bt-susceptible herbivores lived 25% longer, on average, than those that were exposed to these herbivores. In addition, an average B. rapa seedling sprayed with Bt throughout its lifetime was twice as likely to produce siliques and had 251% of the seed output of a seedling exposed to herbivores. The fitness advantage of Bt-based plant protection was apparent in 2004–2005 in half the plants that experienced higher herbivory, and for 2005–2006, was more pronounced in agricultural habitats than in meadows with established, perennial vegetation and less disturbance. Positive effects of Bt-based plant protection and greater fitness in disturbed habitats suggest that crop-wild gene flow may benefit weed populations, and that field tests with herbivore exclusion/addition experiments are feasible alternatives when molecular containment of transgenes restricts field experiments with insect resistant crop-wild hybrids.

Transgenic fish in development for aquaculture could escape from farms and interbreed with wild relatives in the nearby environment. Predicting whether escapes would result in transgene introgression is a major challenge in assessing environmental risks of transgenic fish. Previous studies have simulated gene flow from transgenic fish using mathematical modeling of fitness traits to predict the relative selective value of transgenic genotypes. Here, we present the first study of gene flow over the full life cycle in openly-breeding populations of transgenic animals, along with measurement of fitness traits. We conducted two invasion experiments in which we released two lines of growth-enhanced transgenic fish (T67 and T400), Japanese medaka (Oryzias latipes), into populations of wild-type (W) medaka in structured mesocosms. After several generations, the frequency of transgenic fish varied across replicates in the first invasion experiment (6 months), but the frequency of transgenic fish decreased in the second experiment (19 months). We also measured selected fitness traits in transgenic and wild-type medaka because these traits could be used to predict the relative selective value of a genotype. We found that: T400 males were more fertile than W males; offspring of W females lived longer than those with transgenic mothers; and W and T67 females reached sexual maturity sooner than T400 females. In contrast with other research that reported larger transgenic males had a mating advantage, we found that W males obtained more matings with females than T males; genetic background effects may account for our differing results as we compared W and T fish derived from different strains. The decreasing frequency of transgenic fish in the second invasion experiment suggests that transgenic fish had a selective disadvantage in the experimental environment. Our finding of transgenic advantage of some fitness traits and wild-type advantage in others is consistent with our invasion experiment results.

Prunus species are important commercial fruit (plums, apricot, peach and cherries), nut (almond) and ornamental trees cultivated broadly worldwide. This review compiles information from available literature on Prunus species in regard to gene flow and hybridization within this complex of species. The review serves as a resource for environmental risk assessment related to pollen mediated gene flow and the release of transgenic Prunus. It reveals that Prunus species, especially plums and cherries show high potential for transgene flow. A range of characteristics including; genetic diversity, genetic bridging capacity, inter- and intra-specific genetic compatibility, self sterility (in most species), high frequency of open pollination, insect assisted pollination, perennial nature, complex phenotypic architecture (canopy height, heterogeneous crown, number of flowers produced in an individual plant), tendency to escape from cultivation, and the existence of ornamental and road side Prunus species suggest that there is a tremendous and complicated ability for pollen mediated gene movement among Prunus species. Ploidy differences among Prunus species do not necessarily provide genetic segregation. The characteristics of Prunu s species highlight the complexity of maintaining coexistence between GM and non-GM Prunus if there were commercial production of GM Prunus species. The results of this review suggest that the commercialization of one GM Prunus species can create coexistence issues for commercial non-GM Prunus production. Despite advances in molecular markers and genetic analysis in agroecology, there remains limited information on the ecological diversity, metapopulation nature, population dynamics, and direct measures of gene flow among different subgenera represented in the Prunus genus. Robust environmental impact, biosafety and coexistence assessments for GM Prunus species will require better understanding of the mechanisms of gene flow and hybridization among species within the Prunus species complex.

Whereas the capability of DNA uptake has been well established for numerous species and strains of bacteria grown in vitro, the broader distribution of natural transformability within bacterial communities remains largely unexplored. Here, we investigate the ability of bacterial isolates from the gut of grass grub larvae (Costelytra zealandica (White); Coleoptera: Scarabaeidae) to develop natural genetic competence in vitro. A total of 37 mostly species-divergent strains isolated from the gut of grass grub larvae were selected for spontaneous rifampicin-resistance. Genomic DNA was subsequently isolated from the resistant strains and exposed to sensitive strains grown individually using established filter transformation protocols. DNA isolated from wild-type strains was used as a control. None of the 37 isolates tested exhibited a frequency of conversion to rifampicin-resistance in the presence of DNA at rates that were significantly higher than the rate of spontaneous mutation to rifampicin-resistance in the presence of wild-type DNA (the limit of detection was approximately < 1 culturable transformant per 109 exposed bacteria). To further examine if conditions were conducive to bacterial DNA uptake in the grass grubs gut, we employed the competent bacterium Acinetobacter baylyi strain BD413 as a recipient species for in vivo studies. However, no transformants could be detected above the detection limit of 1 transformant per 103 cells, possibly due to low population density and limited growth of A. baylyi cells in grass grub guts. PCR analysis indicated that chromosomal AcinetobacterDNA remains detectable by PCR for up to 3 days after direct inoculation into the alimentary tract of grass grub larvae. Nevertheless, neither transforming activity of the DNA recovered from the alimentary tract of grass grubs larvae nor competence of bacterial cells recovered from inoculated larvae could be shown.