Regulatory hurdles for genome editing: process- vs. product-based approaches in different regulatory contexts

Novel plant genome editing techniques call for an updated legislation regulating the use of plants produced by genetic engineering or genome editing, especially in the European Union. Established more than 25 years ago and based on a clear distinction between transgenic and conventionally bred plants, the current EU Directives fail to accommodate the new continuum between genetic engineering and conventional breeding. Despite the fact that the Directive 2001/18/EC contains both process- and product-related terms, it is commonly interpreted as a strictly process-based legislation. In view of several new emerging techniques which are closer to the conventional breeding than common genetic engineering, we argue that it should be actually interpreted more in relation to the resulting product. A legal guidance on how to define plants produced by exploring novel genome editing techniques in relation to the decade-old legislation is urgently needed, as private companies and public researchers are waiting impatiently with products and projects in the pipeline. We here outline the process in the EU to develop a legislation that properly matches the scientific progress. As the process is facing several hurdles, we also compare with existing frameworks in other countries and discuss ideas for an alternative regulatory system.     

A consultant's perspective on the regulatory hurdles to adaptive trials

This is a discussion of the following two papers appearing in this special issue on adaptive designs: 'A regulatory view on adaptive/flexible clinical trial design' by H. M. James Hung, Robert T. O'Neill, Sue-Jane Wang and John Lawrence and 'Confirmatory clinical trials with an adaptive design' by Armin Koch.     

International regulatory requirements for Leptospira vaccine potency testing. Roundtable: Current requirements and opportunity for harmonization

Progress continues to be made in the ongoing efforts to replace, reduce, or refine the use of laboratory animals for Leptospira vaccine potency testing in certain markets/regions. Leptospira-containing vaccines, as with many veterinary vaccines, are manufactured and distributed both on a regional basis by local manufacturers and internationally by large multinational firms. Three general scenarios exist for the international testing and distribution of veterinary vaccines including: 1) the importing country recognizes the country of origin's testing and batch release data with no additional testing; 2) the importing country requires the manufacturer to conduct a specific potency assay based on the current importing market's regulations for the importing country or 3) the importing country requires retesting of the product in country prior to distribution. Scenarios 2 and 3 both have the potential to significantly increase the usage of laboratory animals for what may be considered redundant testing. Specific requirements for the importation of Leptospira vaccines in the United States, Europe, and Mexico were presented as well as efforts to reduce the use of laboratory animal testing through the availability of internationally recognized tests.     

Evolution of regulatory enzymes towards functional simplicity

The potential kinetic complexity of polymeric regulatory enzymes does not seem to be often expressed in nature. Most of these enzymes exhibit in fact a rather simple kinetic behaviour. This functional simplicity is probably the consequence of constraints between rate constants or of blocking of some reaction steps. Functional simplicity is believed to have emerged in the course of neo-Darwinian evolution as a consequence of a trend towards an improved functional efficiency. Functional efficiency may be reached, in polymeric regulatory enzymes, when either of the two sets of conditions are met. The first set of conditions implies the occurrence of the unicity of enzyme conformation in any transition state, a loose coupling between subunits and an exact balance of the driving forces exerted by the enzyme in the forward and backward directions of the catalytic step. This situation results in constraints between rate constants which allow degenerescence of the steady state rate equation. The second set of conditions involves again the unicity of enzyme conformation in any of the transition states, associated with a tight coupling of subunits, and a driving force exerted by the enzyme much strongly in the forward than in the backward direction of the catalytic step. These conditions imply blocking of some reaction steps and again degenerescence of the corresponding rate equation. The most frequent types of quaternary structure and subunit interactions, namely loose coupling between subunits, and tight coupling associated with conservation of at least one symmetry axis, have probably emerged as molecular organizations, which precisely allow both functional efficiency and simplicity to occur. Indeed these situations probably represent the term of two different evolutionary trends. Therefore enzymes that have not reached this state usually exhibit more complex kinetic behaviour. Wavy curves, “bumps” and turning points may be considered as manifestations of the ancestral character of an enzyme.     

The emerging international regulatory framework for biotechnology

Debate about the potential risks of genetically modified organisms (GMOs) to the environment or human health spurred attention to biosafety. Biosafety is associated with the safe use of GMOs and, more generally, with the introduction of non-indigenous species into natural or managed ecosystems. Biosafety regulation--the policies and procedures adopted to ensure the environmentally safe application of modern biotechnology--has been extensively discussed at various national and international forums. Much of the discussion has focused on developing guidelines, appropriate legal frameworks and, at the international level, a legally binding international biosafety protocol--the Cartagena Protocol on Biosafety. The Protocol is one among various international instruments and treaties that regulate specific aspects relevant to agricultural biotechnology. The present article presents the main international instruments relevant to biosafety regulation, and their key provisions. While international agreements and standards provide important guidance, they leave significant room for interpretation, and flexibility for countries implementing them. Implementation of biosafety at the national level has proven to be a major challenge, particularly in developing countries, and consequently the actual functioning of the international regulatory framework for biotechnology is still in a state of flux.     

The US FDA and animal cloning: risk and regulatory approach

The Food and Drug Administration's (FDA's) Center for Veterinary Medicine issued a voluntary request to producers of livestock clones not to introduce food from clones or their progeny into commerce until the agency had assessed whether production of cattle, swine, sheep, or goats by somatic cell nuclear transfer (SCNT) posed any unique risks to the animal(s) involved in the process, humans, or other animals by consuming food from those animals, compared with any other assisted reproductive technology (ART) currently in use. Following a comprehensive review, no anomalies were observed in animals produced by cloning that have not also been observed in animals produced by other ARTs and natural mating. Further systematic review on the health of, and composition of meat and milk from, cattle, swine, and goat clones and the progeny of cattle and sheep did not result in the identification of any food-consumption hazards. The agency therefore concluded that food from cattle, swine, and goat clones was as safe to eat as food from animals of those species derived by conventional means. The agency also concluded that food from the progeny of the clone of any species normally consumed for food is as safe to eat as those animals. The article also describes the methodology used by the agency to analyze data and draw these conclusions, the plans the agency has proposed to manage any identified risks, and the risk communication approaches the agency has used.     

Modelling marine protected areas: insights and hurdles

Models provide useful insights into conservation and resource management issues and solutions. Their use to date has highlighted conditions under which no-take marine protected areas (MPAs) may help us to achieve the goals of ecosystem-based management by reducing pressures, and where they might fail to achieve desired goals. For example, static reserve designs are unlikely to achieve desired objectives when applied to mobile species or when compromised by climate-related ecosystem restructuring and range shifts. Modelling tools allow planners to explore a range of options, such as basing MPAs on the presence of dynamic oceanic features, and to evaluate the potential future impacts of alternative interventions compared with ‘no-action’ counterfactuals, under a range of environmental and development scenarios. The modelling environment allows the analyst to test if indicators and management strategies are robust to uncertainties in how the ecosystem (and the broader human–ecosystem combination) operates, including the direct and indirect ecological effects of protection. Moreover, modelling results can be presented at multiple spatial and temporal scales, and relative to ecological, economic and social objectives. This helps to reveal potential ‘surprises'', such as regime shifts, trophic cascades and bottlenecks in human responses. Using illustrative examples, this paper briefly covers the history of the use of simulation models for evaluating MPA options, and discusses their utility and limitations for informing protected area management in the marine realm.     

Immunosensors in medical diagnostics--major hurdles to commercial success.

In the last few years the format of commercial immunoassays has dramatically changed. Automated instruments running up to 180 samples per hour and dry strip or film immunochemistry products are now available. These changes have been precipitated by the need for immunoassays that require less time and skill to perform. To date, no immunosensor technology has been successfully commercialized although a few are purported to be on the brink of being released for sale. Here, B. Manning and T. Maley evaluate the major factors affecting the success of immunosensors.     

Multicenter validation of the analytical accuracy of Salmonella PCR: towards an international standard

As part of a major international project for the validation and standardization of PCR for detection of five major food-borne pathogens, four primer sets specific for Salmonella species were evaluated in-house for their analytical accuracy (selectivity and detection limit) in identifying 43 Salmonella spp. and 47 non-Salmonella strains. The most selective primer set was found to be 139-141 (K. Rahn, S. A. De Grandis, R. C. Clarke, S. A. McEwen, J. E. Galán, C. Ginocchio, R. Curtiss III, and C. L. Gyles, Mol. Cell. Probes 6:271-279, 1992), which targets the invA gene. An extended determination of selectivity by using 364 strains showed that the inclusivity was 99.6% and the exclusivity was 100% for the invA primer set. To indicate possible PCR inhibitors derived from the sample DNA, an internal amplification control (IAC), which was coamplified with the invA target gene, was constructed. In the presence of 300 DNA copies of the IAC, the detection probability for primer set 139-141 was found to be 100% when a cell suspension containing 10(4) CFU/ml was used as the template in the PCR (50 CFU per reaction). The primer set was further validated in an international collaborative study that included 16 participating laboratories. Analysis with 28 coded ("blind") DNA samples revealed an analytical accuracy of 98%. Thus, a simple PCR assay that is specific for Salmonella spp. and amplifies a chromosomal DNA fragment detected by gel electrophoresis was established through extensive validation and is proposed as an international standard. This study addresses the increasing demand of quality assurance laboratories for standard diagnostic methods and presents findings that can facilitate the international comparison and exchange of epidemiological data.