Molecular characterization for food safety assessment of a genetically modified late blight resistant potato: an unusual case.

Standard food safety assessments of genetically modified crops require a thorough molecular characterization of the novel DNA as inserted into the plant that is intended for commercialization, as well as a comparison of agronomic and nutritional characteristics of the genetically modified to the non-modified counterpart. These characterization data are used to identify any unintended changes in the inserted DNA or in the modified plant that would require assessment for safety in addition to the assessment of the intended modification. An unusual case of an unintended effect discovered from the molecular characterization of a genetically modified late blight resistant potato developed for growing in Bangladesh and Indonesia is presented here. Not only was a significant portion of the plasmid vector backbone DNA inserted into the plant along with the intended insertion of an R-gene for late blight resistance, but the inserted DNA was split into two separate fragments and inserted into two separate chromosomes. One fragment carries the R-gene and the other fragment carries the NPTII selectable marker gene and the plasmid backbone DNA. The implications of this for the food safety assessment of this late blight resistant potato are considered.

When Policy Meets Practice: The Dilemma for Guidance on Risk Assessment Under the Cartagena Protocol on Biosafety.

The Conference of the Parties serving as the meeting of the Parties (COP-MOP) to the Cartagena Protocol on Biosafety to the Convention on Biological Diversity decided years ago to undertake the development of guidance on risk assessment of living modified organisms (LMOs) resulting from modern biotechnology, in order to assist the Parties to the protocol to conduct risk assessments in line with the principles and methodology described therein. After many years of working through ad hoc technical expert groups (AHTEG) and open-ended online forum discussions, including an extensive process to test and revise the guidance document, the COP-MOP did not decide to endorse the last version of the document when it was finally presented to them. A failure to achieve consensus that the guidance, as it had evolved, is relevant and useful is seen as a potential setback for many Parties to the protocol with little to no experience with risk assessment. There are a number of reasons for the lack of success in this attempt to develop useful guidance on risk assessment, including a poorly defined and shifting purpose, misplaced expertise, and a misguided testing process, mostly perpetuated by the constraints of using processes of the Convention. These problems with the development of the Guidance on Risk Assessment of LMOs are explored here in an effort to elucidate the missteps that should be avoided and the lessons that can be learned. Most prominent is a need to rely upon the expanding past and present experiences with actual cases of risk assessments of LMOs, if there is to be any further attempt to develop guidance on risk assessment under the Convention and its protocol.

The Integration of Science and Policy in Regulatory Decision-Making: Observations on Scientific Expert Panels Deliberating GM Crops in Centers of Diversity.

Panels of experts with specialized knowledge and experience are often convened to identify and analyze information relevant for risk assessments of GM crops. A perspective on the use of such scientific expert panels is shared here based on panels convened to inform the regulatory strategy for three separate projects developing GM crops for cultivation in Africa: a nutritionally enhanced sorghum, an insect resistant cowpea, and a virus resistant cassava. The panels were convened specifically to consider the risks associated with gene flow from a genetically modified (GM) crop to naturally occurring 'wild' relatives of that crop. In these cases, the experts used problem formulation to identify effects that regulatory authorities may consider to be harmful ("harms") and formulate plausible scenarios that might lead to them, and the availability of information that could determine the likelihood of the steps in the pathway. These panels and the use of problem formulation worked well to gather the existing information and consider the likelihood of harm from gene flow in centers of diversity. However, one important observation from all of these cases is that it is outside the remit of such scientific expert panels to make decisions dependent on policy, such as which harms should be considered and what information should be considered essential in order for a regulatory authority to make a decision about the acceptable level of risk. These experiences of expert panels to inform GM crop risk assessment demonstrate the challenge of integrating science and policy for effective regulatory decision-making.

Risk assessment of gene flow from genetically engineered virus resistant cassava to wild relatives in Africa: an expert panel report.

The probability and consequences of gene flow to wild relatives is typically considered in the environmental risk assessment of genetically engineered crops. This is a report from a discussion by a group of experts who used a problem formulation approach to consider existing information for risk assessment of gene flow from cassava (Manihot esculenta) genetically engineered for virus resistance to the 'wild' (naturalized) relative M. glaziovii in East Africa. Two environmental harms were considered in this case: (1) loss of genetic diversity in the germplasm pool, and (2) loss of valued species, ecosystem resources, or crop yield and quality due to weediness or invasiveness of wild relatives. Based on existing information, it was concluded that gene flow will occur, but it is not likely that this will reduce the genetic diversity in the germplasm pool. There is little existing information about the impact of the virus in natural populations that could be used to inform a prediction about whether virus resistance would lead to an increase in reproduction or survival, hence abundance of M. glaziovii. However, an increase in the abundance of M. glaziovii should be manageable, and would not necessarily lead to the identified environmental harms.

Regulatory considerations surrounding the deployment of Bt-expressing cowpea in Africa: report of the deliberations of an expert panel.

Cowpea (Vigna unguiculata spp unguiculata) is adapted to the drier agro-ecological zones of West Africa where it is a major source of dietary protein and widely used as a fodder crop. Improving the productivity of cowpea can enhance food availability and security in West Africa. Insect predation--predominately from the legume pod borer (Maruca vitrata), flower thrips (Megalurothrips sjostedti) and a complex of pod-sucking bugs (e.g., Clavigralla spp)--is a major yield-limiting factor in West African cowpea production. Dramatic increases in yield are shown when M. vitrata is controlled with insecticides. However, availability, costs, and safety considerations limit pesticides as a viable option for boosting cowpea production. Development of Bt-cowpea through genetic modification (GM) to control the legume pod borer is a promising approach to cowpea improvement. Cowpea expressing the lepidopteran-active Cry1Ab protein from Bacillus thuringiensis is being developed as a first generation Bt-cowpea crop for West Africa. Appropriate stewardship of Bt-cowpea to assure its sustainability under West African conditions is critical to its successful development. A first step in this process is an environmental risk assessment to determine the likelihood and magnitude of adverse effects of the Cry1Ab protein on key environmental protection goals in West Africa. Here we describe the results of an expert panel convened in 2009 to develop the problem formulation phase for Bt-cowpea and to address specific issues around gene flow, non-target arthropods, and insect resistance management.

Biosafety considerations for selectable and scorable markers used in cassava (Manihot esculenta Crantz) biotechnology.

Cassava is an important subsistence crop grown only in the tropics, and represents a major source of calories for many people in developing countries. Improvements in the areas of resistance to insects and viral diseases, enhanced nutritional qualities, reduced cyanogenic content and modified starch characteristics are urgently needed. Traditional breeding is hampered by the nature of the crop, which has a high degree of heterozygosity, irregular flowering, and poor seed set. Biotechnology has the potential to enhance crop improvement efforts, and genetic engineering techniques for cassava have thus been developed over the past decade. Selectable and scorable markers are critical to efficient transformation technology, and must be evaluated for biosafety, as well as efficiency and cost-effectiveness. In order to facilitate research planning and regulatory submission, the literature on biosafety aspects of the selectable and scorable markers currently used in cassava biotechnology is surveyed. The source, mode of action and current use of each marker gene is described. The potential for toxicity, allergenicity, pleiotropic effects, horizontal gene transfer, and the impact of these on food or feed safety and environmental safety is evaluated. Based on extensive information, the selectable marker genes nptII, hpt, bar/pat, and manA, and the scorable marker gene uidA, all have little risk in terms of biosafety. These appear to represent the safest options for use in cassava biotechnology available at this time.