Uncertainties and Knowledge Gaps in the Environmental Risk Assessment of GMOs

THIRD WORLD NETWORK BIOSAFETY INFORMATION SERVICE 

Dear Friends and Colleagues 

Uncertainties and Knowledge Gaps in the Environmental Risk Assessment of GMOs 

A new report by GenØk-Centre for Biosafety, which is the Norwegian National Competence Centre for Biosafety, provides a detailed discussion of uncertainties, knowledge gaps and research needs related to the potential use and introduction of genetically modified organisms (GMOs). It covers GM plants, antibiotic resistance marker genes, GM vaccines, gene therapy and medicinal products containing or consisting of GMOs, GM microorganisms, GM trees and GM salmon.  

The report identifies many unresolved scientific uncertainties and potential adverse effects related to GMOs and their impacts on ecosystems as well as on animal and human health. For instance, most new GM plants are “multistacks”, i.e. containing several transgenes for both herbicide tolerance and insect resistance, but data on the adequacy of the use of less complex parental lines for environmental risk assessments (ERA) of such multistack plants are lacking. In terms of GM trees, it has not been investigated how these will interact with the complex forest, soil and aquatic ecosystems, as a whole. Similarly, the impact of escaped GM salmon on wild salmon populations and the ecosystem in general is lacking.  

The study makes a list of recommendations for further research to address all the gaps identified. These include: the need for the development of uncertainty analyses that can be used for increasing the quality of environmental risk assessments of GMOs, routine assessments of the accumulation of herbicide residues in GM plants, long-term assessments of GM trees to determine whether transgene expression is stable over time, and studies on the effects of GM crops and trees on aquatic organisms. 

The Executive Summary of the report is reproduced below. The full report is available at http://genok.no/wp-content/uploads/2015/11/16102015_Uncertainties_and_Knowledge_gaps_related_to_Environmetal_Risk_Assessment_of_GMOs.pdf

  

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UNCERTAINTY AND KNOWLEDGE GAPS RELATED TO ENVIRONMENTAL RISK ASSESSMENT OF GMOS 

Executive Summary 

This report provides a detailed discussion of uncertainties, knowledge gaps and research needs related to the potential use and introduction of GMOs. It covers GM plants, antibiotic resistance marker genes, GM vaccines, gene therapy and medicinal products containing or consisting of GMOs, as well as GM microorganisms, GM trees and GM salmon.  

GMOs are made by inserting a gene (or several genes) encoding a wanted trait into an organism (of the same species or a different species). The environmental risks associated with such alteration of the genome are evaluated on the basis of present scientific knowledge and analysis of available literature. The report identifies many unresolved scientific uncertainties and potential adverse effects related to GMOs and their impacts on ecosystems, as well as on animal and human health. Particular attention has been given to GMOs relevant in a Norwegian context. The report emphasizes today’s challenges, but also outlines needs for the future, as new GMOs are becoming increasingly more complex. Examples of such novel GMOs are discussed under the different subchapters.  

The most significant identified areas of uncertainty and knowledge gaps in each section are summarized below.  

Common themes  

This report covers numerous kinds of GMOs in different environmental contexts. However, there are common themes which resonate throughout the report, and which contribute to uncertainty and knowledge gaps related to GMOs in general: 

• The novelty of the introduced genes and their products within the context of the recipient organisms, and the potential effects (e.g. pleiotropic effects, interactions with endogenous proteins etc.) that may occur as a result of their introduction.

• Knowledge regarding unintended changes (e.g. recombination, positional effects etc.) introduced into the genomes of recipient organisms due to genetic modification is sparse, and exacerbated by lack of access to test materials and sequence information.

• The imprecision of both the methods used to perform genetic modification, as well the techniques used to characterize the resultant GM organisms.  

Uncertainties and knowledge gaps for GM plants  

• Most new GMPs are “multistacks”, i.e. containing several transgenes for both herbicide tolerance and insect resistance. Data on the adequacy of the use of less complex parental lines for environmental risk assessments (ERA) of multistack plants is lacking.

• Ecosystem complexity and how environmental factors may affect transgene expression is not well understood.

• How co-exposure of one or more herbicides may affect gene expression in the plants is uncertain. Both the expression levels of the transgenic proteins, and other gene products in multistack GMPs is difficult to assess due to lack of data.

• Data on herbicide accumulation in herbicide tolerant GMPs is lacking.

• Unwanted and unintended effects on non–target organisms have been observed and indicate that Cry-toxins are less specific than previously claimed. There is a lack of studies on alternative modes of action for these agricultural toxins.

• Availability of GM plant test material is limited and hampers the possibility for testing by independent scientific institutions. This undermines the quality and credibility of risk assessments.

• There is lack of data for the presence, use and potential transfer of antibiotic resistance (ARM) genes in GMPs. ARM genes may be transferred to other organisms (microorganisms etc.) through horizontal gene transfer.  

Uncertainties and knowledge gaps for GM viruses  

• Available data on baseline information of naturally occurring viruses is generally lacking in ERA.

• The potential for recombination, complementation and reactivation is difficult to assess due to lack of data.

• Molecular basis for host ranges, molecular characterization and immune status of the host and non-target hosts has little data.

• The potential for GM virus shedding and the potential for infection in non-target species is not well understood.  

Uncertainties and knowledge gaps for GM microorganisms (GMMs)  

• There is an incomplete understanding of how GMMs become established within an environment.

• Potential impact of resource competition between GMMs and other microbes in the environment.

• Containment strategies used under field conditions for GMMs (GM bacteria, GM algae, GM fungi) are highly challenging, and the potential for escape is not well explored.

• There is little or no data on how to deal with escaped GMMs.

• Knowledge regarding environmental impacts of large populations of GMMs and their effect on the receiving environment is lacking.

• There is a lack of knowledge on the capacity of GMMs to maintain or transfer transgenes within or between populations.

• Potential for, and possible impacts of, horizontal gene transfer (HGT) between GMMs and non-GMM species is not well understood. 

Uncertainties and knowledge gaps for GM trees  

• The present knowledge on GM trees and the dynamics of gene flow are not fully understood.

• The practical utility of containment strategies for GM trees is not well understood.

• Data is missing on transgene stability of expression over longer time frames. This is highly relevant for GM trees.

• How GM trees will interact with the complex forest, soil and aquatic ecosystems, as a whole, is not investigated.  

Uncertainties and knowledge gaps for GM salmon 

• Salmon is a highly complex and plastic species, thus there might be many effects of genetic modifications that we will not observe in captivity. The production and the effects of GM salmon on the environment is at present uncertain.

• The knowledge on the impact of escaped GM salmon on wild salmon populations and the ecosystem in general is lacking.

• GM fish health and welfare conditions are unknown.  

Recommendations for further research  

• There is a need for development of uncertainty analyses that can be used for increasing the quality of ERA of GMOs.

• More open ERA processes are needed, together with scientific institutions’ access to GMO test material for independent testing and validation of data.

• The potential for combinatorial effects of transgenes expressed in multistack GMPs are high, and the relevance by the use of parental lines as representative controls of stacked events should be assessed.

• The accumulation of herbicide residues in GMPs must be routinely measured.

• Potential transfer of ARM genes to microorganisms and to other organisms should be investigated.

• Natural environments must be investigated for the presence of reservoirs of ARM genes, in order to elucidate whether the use of ARM-containing GMOs could potentially augment the environmental level of resistance.

• Persistence of GM viruses, and in what form (virion, DNA, RNA or protein) they exist outside their hosts, needs to be elucidated.

• Molecular characterization and the basis for host range of GM viruses, as well as immune status of host and at-risk non-target hosts needs to be investigated.

• Long-term assessment of GM trees is required to determine whether transgene expression is stable over time, through seasonal variations and dormancy cycles.

• Aquatic ecosystems have been neglected in previous ERAs. The effect of GM crops and trees on aquatic organisms must be assessed

• Effects on welfare and the environment by GM salmon production and use need to be investigated.

• Impacts on wild salmon upon escape by GM salmon must be elaborated. 

In a Norwegian context we will in addition recommend:  

• Monitoring of baseline data in the environment of ARM, herbicides, natural reservoirs of viruses, target and non-target organisms.

• Evaluation of the relevance of current methods and models in ERA for Norwegian conditions.

• And, if needed, development of new methods and models to be used for ERA and environmental monitoring of GMOs in Norway. 

 

Uncertainties and Knowledge Gaps in the Environmental Risk Assessment of GMOs

UNCERTAINTY AND KNOWLEDGE GAPS RELATED TO ENVIRONMENTAL RISK ASSESSMENT OF GMOS 

Executive Summary 

This report provides a detailed discussion of uncertainties, knowledge gaps and research needs related to the potential use and introduction of GMOs. It covers GM plants, antibiotic resistance marker genes, GM vaccines, gene therapy and medicinal products containing or consisting of GMOs, as well as GM microorganisms, GM trees and GM salmon.

GMOs are made by inserting a gene (or several genes) encoding a wanted trait into an organism (of the same species or a different species). The environmental risks associated with such alteration of the genome are evaluated on the basis of present scientific knowledge and analysis of available literature. The report identifies many unresolved scientific uncertainties and potential adverse effects related to GMOs and their impacts on ecosystems, as well as on animal and human health. Particular attention has been given to GMOs relevant in a Norwegian context. The report emphasizes today’s challenges, but also outlines needs for the future, as new GMOs are becoming increasingly more complex. Examples of such novel GMOs are discussed under the different subchapters.  

The most significant identified areas of uncertainty and knowledge gaps in each section are summarized below.  

Common themes  

This report covers numerous kinds of GMOs in different environmental contexts. However, there are common themes which resonate throughout the report, and which contribute to uncertainty and knowledge gaps related to GMOs in general: 

• The novelty of the introduced genes and their products within the context of the recipient organisms, and the potential effects (e.g. pleiotropic effects, interactions with endogenous proteins etc.) that may occur as a result of their introduction.

• Knowledge regarding unintended changes (e.g. recombination, positional effects etc.) introduced into the genomes of recipient organisms due to genetic modification is sparse, and exacerbated by lack of access to test materials and sequence information.

• The imprecision of both the methods used to perform genetic modification, as well the techniques used to characterize the resultant GM organisms.  

Uncertainties and knowledge gaps for GM plants  

• Most new GMPs are “multistacks”, i.e. containing several transgenes for both herbicide tolerance and insect resistance. Data on the adequacy of the use of less complex parental lines for environmental risk assessments (ERA) of multistack plants is lacking.

• Ecosystem complexity and how environmental factors may affect transgene expression is not well understood.

• How co-exposure of one or more herbicides may affect gene expression in the plants is uncertain. Both the expression levels of the transgenic proteins, and other gene products in multistack GMPs is difficult to assess due to lack of data.

• Data on herbicide accumulation in herbicide tolerant GMPs is lacking.

• Unwanted and unintended effects on non–target organisms have been observed and indicate that Cry-toxins are less specific than previously claimed. There is a lack of studies on alternative modes of action for these agricultural toxins.

• Availability of GM plant test material is limited and hampers the possibility for testing by independent scientific institutions. This undermines the quality and credibility of risk assessments.

• There is lack of data for the presence, use and potential transfer of antibiotic resistance (ARM) genes in GMPs. ARM genes may be transferred to other organisms (microorganisms etc.) through horizontal gene transfer.  

Uncertainties and knowledge gaps for GM viruses  

• Available data on baseline information of naturally occurring viruses is generally lacking in ERA.

• The potential for recombination, complementation and reactivation is difficult to assess due to lack of data.

• Molecular basis for host ranges, molecular characterization and immune status of the host and non-target hosts has little data.

• The potential for GM virus shedding and the potential for infection in non-target species is not well understood.  

Uncertainties and knowledge gaps for GM microorganisms (GMMs)  

• There is an incomplete understanding of how GMMs become established within an environment.

• Potential impact of resource competition between GMMs and other microbes in the environment.

• Containment strategies used under field conditions for GMMs (GM bacteria, GM algae, GM fungi) are highly challenging, and the potential for escape is not well explored.

• There is little or no data on how to deal with escaped GMMs.

• Knowledge regarding environmental impacts of large populations of GMMs and their effect on the receiving environment is lacking.

• There is a lack of knowledge on the capacity of GMMs to maintain or transfer transgenes within or between populations.

• Potential for, and possible impacts of, horizontal gene transfer (HGT) between GMMs and non-GMM species is not well understood. 

Uncertainties and knowledge gaps for GM trees  

• The present knowledge on GM trees and the dynamics of gene flow are not fully understood.

• The practical utility of containment strategies for GM trees is not well understood.

• Data is missing on transgene stability of expression over longer time frames. This is highly relevant for GM trees.

• How GM trees will interact with the complex forest, soil and aquatic ecosystems, as a whole, is not investigated.  

Uncertainties and knowledge gaps for GM salmon 

• Salmon is a highly complex and plastic species, thus there might be many effects of genetic modifications that we will not observe in captivity. The production and the effects of GM salmon on the environment is at present uncertain.

• The knowledge on the impact of escaped GM salmon on wild salmon populations and the ecosystem in general is lacking.

• GM fish health and welfare conditions are unknown.  

Recommendations for further research  

• There is a need for development of uncertainty analyses that can be used for increasing the quality of ERA of GMOs.

• More open ERA processes are needed, together with scientific institutions’ access to GMO test material for independent testing and validation of data.

• The potential for combinatorial effects of transgenes expressed in multistack GMPs are high, and the relevance by the use of parental lines as representative controls of stacked events should be assessed.

• The accumulation of herbicide residues in GMPs must be routinely measured.

• Potential transfer of ARM genes to microorganisms and to other organisms should be investigated.

• Natural environments must be investigated for the presence of reservoirs of ARM genes, in order to elucidate whether the use of ARM-containing GMOs could potentially augment the environmental level of resistance.

• Persistence of GM viruses, and in what form (virion, DNA, RNA or protein) they exist outside their hosts, needs to be elucidated.

• Molecular characterization and the basis for host range of GM viruses, as well as immune status of host and at-risk non-target hosts needs to be investigated.

• Long-term assessment of GM trees is required to determine whether transgene expression is stable over time, through seasonal variations and dormancy cycles.

• Aquatic ecosystems have been neglected in previous ERAs. The effect of GM crops and trees on aquatic organisms must be assessed

• Effects on welfare and the environment by GM salmon production and use need to be investigated.

• Impacts on wild salmon upon escape by GM salmon must be elaborated. 

In a Norwegian context we will in addition recommend:  

• Monitoring of baseline data in the environment of ARM, herbicides, natural reservoirs of viruses, target and non-target organisms.

• Evaluation of the relevance of current methods and models in ERA for Norwegian conditions.

• And, if needed, development of new methods and models to be used for ERA and environmental monitoring of GMOs in Norway.

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