THIRD WORLD NETWORK BIOSAFETY INFORMATION SERVICE
Dear Friends and Colleagues
Serious Threats Posed by Gene Drives for Conservation
CRISPR gene drive has been proposed for population management, including in conservation genetics. The technique would require releasing genetically engineered individuals that are designed to rapidly propagate a desired mutation or transgene into wild populations. Potential applications in conservation biology include the control of invasive pest populations that threaten biodiversity (eradication and suppression drives), or the introduction of beneficial mutations in endangered populations or removing deleterious ones (rescue drives). A target population fixed for an eradication drive will go extinct.
A review of the potential applications of gene drives for conservation identified potential hazards. Most of risks associated with population management using eradication and suppression drives are not specific to conservation and can also be expected in applications for human health and agriculture. Such risks include: (a) molecular off-target mutations; (b) propagation to non-target populations especially on islands; (c) propagation to non-target species through horizontal gene transfer via parasites, pathogens or endosymbionts (e.g. viruses, bacteria, fungi) in plants or parasitoids in animals; (d) consequences for ecosystems, for example, removing invasive species might have unanticipated negative impacts on ecosystems through indirect effects on food webs and eradicating an invasive species can move the ecosystem further away from its equilibrium without returning to its pre-invasion state, sometimes even making the system more susceptible to new invasions; (e) risk of failure of countermeasures to stop an on-going drive.
Because their implementation could have far-reaching unintended consequences and could trigger irremediable modification of the natural environment, gene drives for conservation purposes pose serious threats. The authors stress that what is needed is informed decision-making, more biosafety research, and strong ethical and regulatory oversight. The safety of gene drive research projects should be assessed by independent experts.
Regulating gene drives requires ethical principles considering both human social values and non-human environmental values. Given the high risks of propagation of gene drive individuals across borders, there is a pressing need to build strong international and national GMO regulatory frameworks that are adapted to the specificities of gene drive organisms. Finally, there should be transparency in gene drive research programmes (including their funding sources and an appropriate risk assessment) and a broad engagement of evolutionary biologists with the public so that stakeholders and local communities can make informed decisions.
With best wishes,
Third World Network
131 Jalan Macalister
10400 Penang
Malaysia
Email: twn@twnetwork.org
Websites: http://www.twn.my/and http://www.biosafety-info.net/
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POPULATION MANAGEMENT USING GENE DRIVE: MOLECULAR DESIGN, MODELS OF SPREAD DYNAMICS AND ASSESSMENT OF ECOLOGICAL RISKS
Nicolas O. Rode1 et al.
Conservation Genetics (2019) 20:671–690
DOI: https://doi.org/10.1007/s10592-019-01165-5
April 2019
https://link.springer.com/article/10.1007/s10592-019-01165-5
Abstract
CRISPR gene drive has recently been proposed as a promising technology for population management, including in conservation genetics. The technique would consist in releasing genetically engineered individuals that are designed to rapidly propagate a desired mutation or transgene into wild populations. Potential applications in conservation biology include the control of invasive pest populations that threaten biodiversity (eradication and suppression drives), or the introduction of beneficial mutations in endangered populations (rescue drives). The propagation of a gene drive is affected by different factors that depend on the drive construct (e.g. its fitness effect and timing of expression) or on the target species (e.g. its mating system and population structure). We review potential applications of the different types of gene drives for conservation. We examine the challenges posed by the evolution of resistance to gene drives and review the various molecular and environmental risks associated with gene drives (e.g. propagation to non-target populations or species and unintended detrimental ecosystem impacts). We provide some guidelines for future gene drive research and discuss ethical, biosafety and regulation issues.