1
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Combs MA, Golnar AJ, Overcash JM, Lloyd AL, Hayes KR, O'Brochta DA, Pepin KM. Leveraging eco-evolutionary models for gene drive risk assessment. Trends Genet 2023:S0168-9525(23)00090-2. [PMID: 37198063 DOI: 10.1016/j.tig.2023.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 04/07/2023] [Accepted: 04/14/2023] [Indexed: 05/19/2023]
Abstract
Engineered gene drives create potential for both widespread benefits and irreversible harms to ecosystems. CRISPR-based systems of allelic conversion have rapidly accelerated gene drive research across diverse taxa, putting field trials and their necessary risk assessments on the horizon. Dynamic process-based models provide flexible quantitative platforms to predict gene drive outcomes in the context of system-specific ecological and evolutionary features. Here, we synthesize gene drive dynamic modeling studies to highlight research trends, knowledge gaps, and emergent principles, organized around their genetic, demographic, spatial, environmental, and implementation features. We identify the phenomena that most significantly influence model predictions, discuss limitations of biological complexity and uncertainty, and provide insights to promote responsible development and model-assisted risk assessment of gene drives.
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Affiliation(s)
- Matthew A Combs
- National Wildlife Research Center, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, Fort Collins, CO, 80521, USA.
| | - Andrew J Golnar
- National Wildlife Research Center, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, Fort Collins, CO, 80521, USA
| | - Justin M Overcash
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Biotechnology Regulatory Services, 20737, USA
| | - Alun L Lloyd
- North Carolina State University, Biomathematics Graduate Program and Department of Mathematics, Raleigh, NC, 27695, USA
| | - Keith R Hayes
- The Commonwealth Scientific and Industrial Research Organisation, Data 61, Hobart, TAS, 7004, Australia
| | - David A O'Brochta
- Foundation for the National Institutes of Health, North Bethesda, MD, 20852, USA
| | - Kim M Pepin
- National Wildlife Research Center, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, Fort Collins, CO, 80521, USA
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2
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Frieß JL, Lalyer CR, Giese B, Simon S, Otto M. Review of gene drive modelling and implications for risk assessment of gene drive organisms. Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2023.110285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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3
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Bunting MD, Pfitzner C, Gierus L, White M, Piltz S, Thomas PQ. Generation of Gene Drive Mice for Invasive Pest Population Suppression. Methods Mol Biol 2022; 2495:203-230. [PMID: 35696035 DOI: 10.1007/978-1-0716-2301-5_11] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Gene drives are genetic elements that are transmitted to greater than 50% of offspring and have potential for population modification or suppression. While gene drives are known to occur naturally, the recent emergence of CRISPR-Cas9 genome-editing technology has enabled generation of synthetic gene drives in a range of organisms including mosquitos, flies, and yeast. For example, studies in Anopheles mosquitos have demonstrated >95% transmission of CRISPR-engineered gene drive constructs, providing a possible strategy for malaria control. Recently published studies have also indicated that it may be possible to develop gene drive technology in invasive rodents such as mice. Here, we discuss the prospects for gene drive development in mice, including synthetic "homing drive" and X-shredder strategies as well as modifications of the naturally occurring t haplotype. We also provide detailed protocols for generation of gene drive mice through incorporation of plasmid-based transgenes in a targeted and non-targeted manner. Importantly, these protocols can be used for generating transgenic mice for any project that requires insertion of kilobase-scale transgenes such as knock-in of fluorescent reporters, gene swaps, overexpression/ectopic expression studies, and conditional "floxed" alleles.
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Affiliation(s)
- Mark D Bunting
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Chandran Pfitzner
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Luke Gierus
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Melissa White
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia
- South Australian Genome Editing Facility, North Terrace, Adelaide, SA, Australia
| | - Sandra Piltz
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia
- South Australian Genome Editing Facility, North Terrace, Adelaide, SA, Australia
| | - Paul Q Thomas
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia.
- South Australian Genome Editing Facility, North Terrace, Adelaide, SA, Australia.
- South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, Australia.
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4
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Verma P, Reeves RG, Gokhale CS. A common gene drive language eases regulatory process and eco-evolutionary extensions. BMC Ecol Evol 2021; 21:156. [PMID: 34372763 PMCID: PMC8351217 DOI: 10.1186/s12862-021-01881-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 07/12/2021] [Indexed: 02/08/2023] Open
Abstract
Background Synthetic gene drive technologies aim to spread transgenic constructs into wild populations even when they impose organismal fitness disadvantages. The extraordinary diversity of plausible drive mechanisms and the range of selective parameters they may encounter makes it very difficult to convey their relative predicted properties, particularly where multiple approaches are combined. The sheer number of published manuscripts in this field, experimental and theoretical, the numerous techniques resulting in an explosion in the gene drive vocabulary hinder the regulators’ point of view. We address this concern by defining a simplified parameter based language of synthetic drives. Results Employing the classical population dynamics approach, we show that different drive construct (replacement) mechanisms can be condensed and evaluated on an equal footing even where they incorporate multiple replacement drives approaches. Using a common language, it is then possible to compare various model properties, a task desired by regulators and policymakers. The generalization allows us to extend the study of the invasion dynamics of replacement drives analytically and, in a spatial setting, the resilience of the released drive constructs. The derived framework is available as a standalone tool. Conclusion Besides comparing available drive constructs, our tool is also useful for educational purpose. Users can also explore the evolutionary dynamics of future hypothetical combination drive scenarios. Thus, our results appraise the properties and robustness of drives and provide an intuitive and objective way for risk assessment, informing policies, and enhancing public engagement with proposed and future gene drive approaches.
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Affiliation(s)
- Prateek Verma
- Research Group for Theoretical Models of Eco-evolutionary Dynamics, Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plön, Germany.
| | - R Guy Reeves
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Chaitanya S Gokhale
- Research Group for Theoretical Models of Eco-evolutionary Dynamics, Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plön, Germany
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5
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Edgington MP, Harvey-Samuel T, Alphey L. Split drive killer-rescue provides a novel threshold-dependent gene drive. Sci Rep 2020; 10:20520. [PMID: 33239631 PMCID: PMC7689494 DOI: 10.1038/s41598-020-77544-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 11/12/2020] [Indexed: 12/20/2022] Open
Abstract
A wide range of gene drive mechanisms have been proposed that are predicted to increase in frequency within a population even when they are deleterious to individuals carrying them. This also allows associated desirable genetic material ("cargo genes") to increase in frequency. Gene drives have garnered much attention for their potential use against a range of globally important problems including vector borne disease, crop pests and invasive species. Here we propose a novel gene drive mechanism that could be engineered using a combination of toxin-antidote and CRISPR components, each of which are already being developed for other purposes. Population genetics mathematical models are developed here to demonstrate the threshold-dependent nature of the proposed system and its robustness to imperfect homing, incomplete penetrance of toxins and transgene fitness costs, each of which are of practical significance given that real-world components inevitably have such imperfections. We show that although end-joining repair mechanisms may cause the system to break down, under certain conditions, it should persist over time scales relevant for genetic control programs. The potential of such a system to provide localised population suppression via sex ratio distortion or female-specific lethality is also explored. Additionally, we investigate the effect on introduction thresholds of adding an extra CRISPR base element, showing that this may either increase or decrease dependent on parameter context.
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Affiliation(s)
| | - Tim Harvey-Samuel
- The Pirbright Institute, Ash Road, Woking, Surrey, Pirbright, GU24 0NF, UK
| | - Luke Alphey
- The Pirbright Institute, Ash Road, Woking, Surrey, Pirbright, GU24 0NF, UK
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6
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Dhole S, Lloyd AL, Gould F. Gene Drive Dynamics in Natural Populations: The Importance of Density Dependence, Space, and Sex. ANNUAL REVIEW OF ECOLOGY, EVOLUTION, AND SYSTEMATICS 2020; 51:505-531. [PMID: 34366722 PMCID: PMC8340601 DOI: 10.1146/annurev-ecolsys-031120-101013] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The spread of synthetic gene drives is often discussed in the context of panmictic populations connected by gene flow and described with simple deterministic models. Under such assumptions, an entire species could be altered by releasing a single individual carrying an invasive gene drive, such as a standard homing drive. While this remains a theoretical possibility, gene drive spread in natural populations is more complex and merits a more realistic assessment. The fate of any gene drive released in a population would be inextricably linked to the population's ecology. Given the uncertainty often involved in ecological assessment of natural populations, understanding the sensitivity of gene drive spread to important ecological factors is critical. Here we review how different forms of density dependence, spatial heterogeneity, and mating behaviors can impact the spread of self-sustaining gene drives. We highlight specific aspects of gene drive dynamics and the target populations that need further research.
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Affiliation(s)
- Sumit Dhole
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Alun L Lloyd
- Biomathematics Graduate Program and Department of Mathematics, North Carolina State University, Raleigh, North Carolina 27695-8213, USA
- Genetic Engineering and Society Center, North Carolina State University, Raleigh, North Carolina 27695-7565, USA
| | - Fred Gould
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina 27695, USA
- Genetic Engineering and Society Center, North Carolina State University, Raleigh, North Carolina 27695-7565, USA
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7
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Price TAR, Windbichler N, Unckless RL, Sutter A, Runge JN, Ross PA, Pomiankowski A, Nuckolls NL, Montchamp-Moreau C, Mideo N, Martin OY, Manser A, Legros M, Larracuente AM, Holman L, Godwin J, Gemmell N, Courret C, Buchman A, Barrett LG, Lindholm AK. Resistance to natural and synthetic gene drive systems. J Evol Biol 2020; 33:1345-1360. [PMID: 32969551 PMCID: PMC7796552 DOI: 10.1111/jeb.13693] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/10/2020] [Accepted: 08/13/2020] [Indexed: 02/06/2023]
Abstract
Scientists are rapidly developing synthetic gene drive elements intended for release into natural populations. These are intended to control or eradicate disease vectors and pests, or to spread useful traits through wild populations for disease control or conservation purposes. However, a crucial problem for gene drives is the evolution of resistance against them, preventing their spread. Understanding the mechanisms by which populations might evolve resistance is essential for engineering effective gene drive systems. This review summarizes our current knowledge of drive resistance in both natural and synthetic gene drives. We explore how insights from naturally occurring and synthetic drive systems can be integrated to improve the design of gene drives, better predict the outcome of releases and understand genomic conflict in general.
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Affiliation(s)
- Tom A. R. Price
- Department of Ecology, Evolution and Behaviour, University of Liverpool, Liverpool L69 7ZB, UK
| | - Nikolai Windbichler
- Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | | | - Andreas Sutter
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, UK
| | - Jan-Niklas Runge
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland
| | - Perran A. Ross
- Bio21 and the School of Biosciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Andrew Pomiankowski
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | | | - Catherine Montchamp-Moreau
- Evolution Génome Comportement et Ecologie, CNRS, IRD, Université Paris-Saclay, Gif sur Yvette 91190, France
| | - Nicole Mideo
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON M5S 3B2 Canada
| | - Oliver Y. Martin
- Department of Biology (D-BIOL) & Institute of Integrative Biology (IBZ), ETH Zurich, Universitätsstrasse 16, CH 8092 Zurich, Switzerland
| | - Andri Manser
- Department of Ecology, Evolution and Behaviour, University of Liverpool, Liverpool L69 7ZB, UK
| | - Matthieu Legros
- CSIRO Agriculture and Food, Canberra, Australian Capital Territory, Australia
| | | | - Luke Holman
- School of Biosciences, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - John Godwin
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Neil Gemmell
- Department of Anatomy, University of Otago, Dunedin 9054, New Zealand
| | - Cécile Courret
- Evolution Génome Comportement et Ecologie, CNRS, IRD, Université Paris-Saclay, Gif sur Yvette 91190, France
- Department of Biology, University of Rochester, Rochester, New York, USA
| | - Anna Buchman
- University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093
- Verily Life Sciences, 269 E Grand Ave, South San Francisco, CA 94080
| | - Luke G. Barrett
- CSIRO Agriculture and Food, Canberra, Australian Capital Territory, Australia
| | - Anna K. Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland
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8
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Edgington MP, Harvey‐Samuel T, Alphey L. Population-level multiplexing: A promising strategy to manage the evolution of resistance against gene drives targeting a neutral locus. Evol Appl 2020; 13:1939-1948. [PMID: 32908596 PMCID: PMC7463328 DOI: 10.1111/eva.12945] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/19/2020] [Accepted: 02/25/2020] [Indexed: 01/30/2023] Open
Abstract
CRISPR-based gene drives bias inheritance in their favour by inducing double-stranded breaks (DSBs) at wild-type homologous loci and using the drive transgene as a repair template-converting drive heterozygotes into homozygotes. Recent studies have shown that alternate end-joining repair mechanisms produce cut-resistant alleles that rapidly induce drive failure. Multiplexing-simultaneously targeting multiple sites at the wild-type locus-is commonly assumed to overcome this issue since resistance would need to develop at all target sites for the system to fail. This may work for some population suppression drives targeting essential (e.g. viability or fertility) genes if careful design can ensure cut-resistant alleles themselves have low fitness. However, here, models are used to demonstrate that this approach will be ineffective when targeting neutral loci. We then go on to compare the performance of four alternative population-level multiplexing approaches with standard individual-level multiplexing. Two of these approaches have mechanisms preventing them from becoming linked, thus avoiding multiple simultaneous DSBs and giving a large improvement. Releasing multiple unlinked drives gives a modest improvement, while releasing multiple drives that may become linked over time produces a decrease in performance under the conditions tested here. Based on performance and technical feasibility, we then take one approach forward for further investigation, demonstrating its robustness to different performance parameters and its potential for controlling very large target populations.
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9
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Serr ME, Valdez RX, Barnhill-Dilling KS, Godwin J, Kuiken T, Booker M. Scenario analysis on the use of rodenticides and sex-biasing gene drives for the removal of invasive house mice on islands. Biol Invasions 2020. [DOI: 10.1007/s10530-019-02192-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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10
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Harvey‐Samuel T, Norman VC, Carter R, Lovett E, Alphey L. Identification and characterization of a Masculinizer homologue in the diamondback moth, Plutella xylostella. INSECT MOLECULAR BIOLOGY 2020; 29:231-240. [PMID: 31793118 PMCID: PMC7079136 DOI: 10.1111/imb.12628] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 11/02/2019] [Accepted: 11/27/2019] [Indexed: 05/19/2023]
Abstract
Recently, a novel sex-determination system was identified in the silkworm (Bombyx mori) in which a piwi-interacting RNA (piRNA) encoded on the female-specific W chromosome silences a Z-linked gene (Masculinizer) that would otherwise initiate male sex-determination and dosage compensation. Masculinizer provides various opportunities for developing improved genetic pest management tools. A pest lepidopteran in which a genetic pest management system has been developed, but which would benefit greatly from such improved designs, is the diamondback moth, Plutella xylostella. However, Masculinizer has not yet been identified in this species. Here, focusing on the previously described 'masculinizing' domain of B. mori Masculinizer, we identify P. xylostella Masculinizer (PxyMasc). We show that PxyMasc is Z-linked, regulates sex-specific alternative splicing of doublesex and is necessary for male survival. Similar results in B. mori suggest this survival effect is possibly through failure to initiate male dosage compensation. The highly conserved function and location of this gene between these two distantly related lepidopterans suggests a deep role for Masculinizer in the sex-determination systems of the Lepidoptera.
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11
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Browett SS, O'Meara DB, McDevitt AD. Genetic tools in the management of invasive mammals: recent trends and future perspectives. Mamm Rev 2020. [DOI: 10.1111/mam.12189] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Samuel S. Browett
- Ecosystems and Environment Research Centre School of Science, Engineering and Environment University of Salford Salford M5 4WTUK
| | - Denise B. O'Meara
- Molecular Ecology Research Group Eco‐Innovation Research Centre School of Science and Computing Waterford Institute of Technology Waterford Ireland
| | - Allan D. McDevitt
- Ecosystems and Environment Research Centre School of Science, Engineering and Environment University of Salford Salford M5 4WTUK
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12
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Landis WG, Brown EA, Eikenbary S. An Initial Framework for the Environmental Risk Assessment of Synthetic Biology-Derived Organisms with a Focus on Gene Drives. RISK, SYSTEMS AND DECISIONS 2020. [DOI: 10.1007/978-3-030-27264-7_11] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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13
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Wedell N, Price TAR, Lindholm AK. Gene drive: progress and prospects. Proc Biol Sci 2019; 286:20192709. [PMID: 31847764 PMCID: PMC6939923 DOI: 10.1098/rspb.2019.2709] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 11/26/2019] [Indexed: 12/12/2022] Open
Abstract
Gene drive is a naturally occurring phenomenon in which selfish genetic elements manipulate gametogenesis and reproduction to increase their own transmission to the next generation. Currently, there is great excitement about the potential of harnessing such systems to control major pest and vector populations. If synthetic gene drive systems can be constructed and applied to key species, they may be able to rapidly spread either modifying or eliminating the targeted populations. This approach has been lauded as a revolutionary and efficient mechanism to control insect-borne diseases and crop pests. Driving endosymbionts have already been deployed to combat the transmission of dengue and Zika virus in mosquitoes. However, there are a variety of barriers to successfully implementing gene drive techniques in wild populations. There is a risk that targeted organisms will rapidly evolve an ability to suppress the synthetic drive system, rendering it ineffective. There are also potential risks of synthetic gene drivers invading non-target species or populations. This Special Feature covers the current state of affairs regarding both natural and synthetic gene drive systems with the aim to identify knowledge gaps. By understanding how natural drive systems spread through populations, we may be able to better predict the outcomes of synthetic drive release.
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Affiliation(s)
- N. Wedell
- Department of Biosciences, University of Exeter, Penryn Campus, Penryn TR10 9FE, UK
| | - T. A. R. Price
- Institution for Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - A. K. Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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14
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Lindholm A, Sutter A, Künzel S, Tautz D, Rehrauer H. Effects of a male meiotic driver on male and female transcriptomes in the house mouse. Proc Biol Sci 2019; 286:20191927. [PMID: 31718496 PMCID: PMC6892043 DOI: 10.1098/rspb.2019.1927] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/21/2019] [Indexed: 01/01/2023] Open
Abstract
Not all genetic loci follow Mendel's rules, and the evolutionary consequences of this are not yet fully known. Genomic conflict involving multiple loci is a likely outcome, as restoration of Mendelian inheritance patterns will be selected for, and sexual conflict may also arise when sexes are differentially affected. Here, we investigate effects of the t haplotype, an autosomal male meiotic driver in house mice, on genome-wide gene expression patterns in males and females. We analysed gonads, liver and brain in adult same-sex sibling pairs differing in genotype, allowing us to identify t-associated differences in gene regulation. In testes, only 40% of differentially expressed genes mapped to the approximately 708 annotated genes comprising the t haplotype. Thus, much of the activity of the t haplotype occurs in trans, and as upregulation. Sperm maturation functions were enriched among both cis and trans acting t haplotype genes. Within the t haplotype, we observed more downregulation and differential exon usage. In ovaries, liver and brain, the majority of expression differences mapped to the t haplotype, and were largely independent of the differences seen in the testis. Overall, we found widespread transcriptional effects of this male meiotic driver in the house mouse genome.
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Affiliation(s)
- Anna Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Andreas Sutter
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, UK
| | - Sven Künzel
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Strasse 2, 24306 Plön, Germany
| | - Diethard Tautz
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Strasse 2, 24306 Plön, Germany
| | - Hubert Rehrauer
- Functional Genomics Center Zurich, ETH Zurich/University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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15
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Godwin J, Serr M, Barnhill-Dilling SK, Blondel DV, Brown PR, Campbell K, Delborne J, Lloyd AL, Oh KP, Prowse TAA, Saah R, Thomas P. Rodent gene drives for conservation: opportunities and data needs. Proc Biol Sci 2019; 286:20191606. [PMID: 31690240 PMCID: PMC6842857 DOI: 10.1098/rspb.2019.1606] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/11/2019] [Indexed: 12/18/2022] Open
Abstract
Invasive rodents impact biodiversity, human health and food security worldwide. The biodiversity impacts are particularly significant on islands, which are the primary sites of vertebrate extinctions and where we are reaching the limits of current control technologies. Gene drives may represent an effective approach to this challenge, but knowledge gaps remain in a number of areas. This paper is focused on what is currently known about natural and developing synthetic gene drive systems in mice, some key areas where key knowledge gaps exist, findings in a variety of disciplines relevant to those gaps and a brief consideration of how engagement at the regulatory, stakeholder and community levels can accompany and contribute to this effort. Our primary species focus is the house mouse, Mus musculus, as a genetic model system that is also an important invasive pest. Our primary application focus is the development of gene drive systems intended to reduce reproduction and potentially eliminate invasive rodents from islands. Gene drive technologies in rodents have the potential to produce significant benefits for biodiversity conservation, human health and food security. A broad-based, multidisciplinary approach is necessary to assess this potential in a transparent, effective and responsible manner.
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Affiliation(s)
- John Godwin
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
- Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC 27695, USA
- W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Megan Serr
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | | | - Dimitri V. Blondel
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Peter R. Brown
- Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Canberra, Australian Capital Territory, Australia
| | - Karl Campbell
- Island Conservation, Charles Darwin Avenue, Puerto Ayora, Galapagos Islands, Ecuador
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, Queensland, Australia
| | - Jason Delborne
- Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC 27695, USA
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USA
| | - Alun L. Lloyd
- Department of Mathematics, North Carolina State University, Raleigh, NC 27695, USA
| | - Kevin P. Oh
- National Wildlife Research Center, US Department of Agriculture, Fort Collins, CO 80521, USA
| | - Thomas A. A. Prowse
- School of Mathematical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Royden Saah
- Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC 27695, USA
- Island Conservation, Charles Darwin Avenue, Puerto Ayora, Galapagos Islands, Ecuador
| | - Paul Thomas
- School of Medicine, The University of Adelaide, Adelaide, South Australia, Australia
- South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
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16
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Locally Fixed Alleles: A method to localize gene drive to island populations. Sci Rep 2019; 9:15821. [PMID: 31676762 PMCID: PMC6825234 DOI: 10.1038/s41598-019-51994-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 10/11/2019] [Indexed: 01/08/2023] Open
Abstract
Invasive species pose a major threat to biodiversity on islands. While successes have been achieved using traditional removal methods, such as toxicants aimed at rodents, these approaches have limitations and various off-target effects on island ecosystems. Gene drive technologies designed to eliminate a population provide an alternative approach, but the potential for drive-bearing individuals to escape from the target release area and impact populations elsewhere is a major concern. Here we propose the “Locally Fixed Alleles” approach as a novel means for localizing elimination by a drive to an island population that exhibits significant genetic isolation from neighboring populations. Our approach is based on the assumption that in small island populations of rodents, genetic drift will lead to alleles at multiple genomic loci becoming fixed. In contrast, multiple alleles are likely to be maintained in larger populations on mainlands. Utilizing the high degree of genetic specificity achievable using homing drives, for example based on the CRISPR/Cas9 system, our approach aims at employing one or more locally fixed alleles as the target for a gene drive on a particular island. Using mathematical modeling, we explore the feasibility of this approach and the degree of localization that can be achieved. We show that across a wide range of parameter values, escape of the drive to a neighboring population in which the target allele is not fixed will at most lead to modest transient suppression of the non-target population. While the main focus of this paper is on elimination of a rodent pest from an island, we also discuss the utility of the locally fixed allele approach for the goals of population suppression or population replacement. Our analysis also provides a threshold condition for the ability of a gene drive to invade a partially resistant population.
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17
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Wong HWS, Holman L. Fitness consequences of the selfish supergene Segregation Distorter. J Evol Biol 2019; 33:89-100. [PMID: 31605400 DOI: 10.1111/jeb.13549] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 10/04/2019] [Indexed: 12/01/2022]
Abstract
Segregation distorters are selfish genetic elements that subvert Mendelian inheritance, often by destroying gametes that do not carry the distorter. Simple theoretical models predict that distorter alleles will either spread to fixation or stabilize at some high intermediate frequency. However, many distorters have substantially lower allele frequencies than predicted by simple models, suggesting that key sources of selection remain to be discovered. Here, we measured the fitness of Drosophila melanogaster adults and juveniles carrying zero, one or two copies of three different variants of the naturally occurring supergene Segregation Distorter (SD), in order to investigate why SD alleles remain relatively rare within populations despite being preferentially inherited. First, we show that the three SD variants differ in the severity and dominance of the fitness costs they impose on individuals carrying them. Second, SD-carrying parents produced less fit offspring in some crosses, independent of offspring genotype, indicating that SD alleles can have nongenetic, transgenerational costs in addition to their direct costs. Third, we found that SD carriers sometimes produce a biased offspring sex ratio, perhaps due to off-target effects of SD on the sex chromosomes. Finally, we used a theoretical model to investigate how sex ratio and transgenerational effects alter the population genetics of distorter alleles; accounting for these additional costs helps to explain why real-world segregation distorter alleles are rarer than predicted.
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Affiliation(s)
- Heidi W S Wong
- School of Biosciences, University of Melbourne, Parkville, Vic., Australia
| | - Luke Holman
- School of Biosciences, University of Melbourne, Parkville, Vic., Australia
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18
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Backus GA, Delborne JA. Threshold-Dependent Gene Drives in the Wild: Spread, Controllability, and Ecological Uncertainty. Bioscience 2019. [DOI: 10.1093/biosci/biz098] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AbstractGene drive technology could allow the intentional spread of a desired gene throughout an entire wild population in relatively few generations. However, there are major concerns that gene drives could either fail to spread or spread without restraint beyond the targeted population. One potential solution is to use more localized threshold-dependent drives, which only spread when they are released in a population above a critical frequency. However, under certain conditions, small changes in gene drive fitness could lead to divergent outcomes in spreading behavior. In the face of ecological uncertainty, the inability to estimate gene drive fitness in a real-world context could prove problematic because gene drives designed to be localized could spread to fixation in neighboring populations if ecological conditions unexpectedly favor the gene drive. This perspective offers guidance to developers and managers because navigating gene drive spread and controllability could be risky without detailed knowledge of ecological contexts.
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19
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Dhole S, Lloyd AL, Gould F. Tethered homing gene drives: A new design for spatially restricted population replacement and suppression. Evol Appl 2019; 12:1688-1702. [PMID: 31462923 PMCID: PMC6708424 DOI: 10.1111/eva.12827] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 05/06/2019] [Accepted: 05/10/2019] [Indexed: 12/18/2022] Open
Abstract
Optimism regarding potential epidemiological and conservation applications of modern gene drives is tempered by concern about the possibility of unintended spread of engineered organisms beyond the target population. In response, several novel gene drive approaches have been proposed that can, under certain conditions, locally alter characteristics of a population. One challenge for these gene drives is the difficulty of achieving high levels of localized population suppression without very large releases in the face of gene flow. We present a new gene drive system, tethered homing (TH), with improved capacity for both localization and population suppression. The TH drive is based on driving a payload gene using a homing construct that is anchored to a spatially restricted gene drive. We use a proof-of-concept mathematical model to show the dynamics of a TH drive that uses engineered underdominance as an anchor. This system is composed of a split homing drive and a two-locus engineered underdominance drive linked to one part of the split drive (the Cas endonuclease). We use simple population genetic simulations to show that the tethered homing technique can offer improved localized spread of costly transgenic payload genes. Additionally, the TH system offers the ability to gradually adjust the genetic load in a population after the initial alteration, with minimal additional release effort. We discuss potential solutions for improving localization and the feasibility of creating TH drive systems. Further research with models that include additional biological details will be needed to better understand how TH drives would behave in natural populations, but the preliminary results shown here suggest that tethered homing drives can be a useful addition to the repertoire of localized gene drives.
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Affiliation(s)
- Sumit Dhole
- Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNorth Carolina
| | - Alun L. Lloyd
- Biomathematics Graduate Program and Department of MathematicsNorth Carolina State UniversityRaleighNorth Carolina
- Genetic Engineering and Society CenterNorth Carolina State UniversityRaleighNorth Carolina
| | - Fred Gould
- Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNorth Carolina
- Genetic Engineering and Society CenterNorth Carolina State UniversityRaleighNorth Carolina
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20
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Manser A, Cornell SJ, Sutter A, Blondel DV, Serr M, Godwin J, Price TAR. Controlling invasive rodents via synthetic gene drive and the role of polyandry. Proc Biol Sci 2019; 286:20190852. [PMID: 31431159 PMCID: PMC6732378 DOI: 10.1098/rspb.2019.0852] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 07/25/2019] [Indexed: 12/25/2022] Open
Abstract
House mice are a major ecosystem pest, particularly threatening island ecosystems as a non-native invasive species. Rapid advances in synthetic biology offer new avenues to control pest species for biodiversity conservation. Recently, a synthetic sperm-killing gene drive construct called t-Sry has been proposed as a means to eradicate target mouse populations owing to a lack of females. A factor that has received little attention in the discussion surrounding such drive applications is polyandry. Previous research has demonstrated that sperm-killing drivers are extremely damaging to a male's sperm competitive ability. Here, we examine the importance of this effect on the t-Sry system using a theoretical model. We find that polyandry substantially hampers the spread of t-Sry such that release efforts have to be increased three- to sixfold for successful eradication. We discuss the implications of our finding for potential pest control programmes, the risk of drive spread beyond the target population, and the emergence of drive resistance. Our work highlights that a solid understanding of the forces that determine drive dynamics in a natural setting is key for successful drive application, and that exploring the natural diversity of gene drives may inform effective gene drive design.
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Affiliation(s)
- Andri Manser
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Liverpool, UK
| | - Stephen J. Cornell
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Liverpool, UK
| | - Andreas Sutter
- Centre for Ecology, Evolution and Conservation, University of East Anglia, Norwich, UK
| | - Dimitri V. Blondel
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695-7617, USA
| | - Megan Serr
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695-7617, USA
| | - John Godwin
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695-7617, USA
| | - Tom A. R. Price
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Liverpool, UK
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21
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Sustainability as a Framework for Considering Gene Drive Mice for Invasive Rodent Eradication. SUSTAINABILITY 2019. [DOI: 10.3390/su11051334] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Gene drives represent a dynamic and controversial set of technologies with applications that range from mosquito control to the conservation of biological diversity on islands. Currently, gene drives are being developed in mice that may one day serve as an important tool for reducing invasive rodent pests, a key threat to island biodiversity and economies. Gene drives in mice are still in development in laboratories, and wild release of modified mice is likely a distant reality. However, technological changes outpace the existing capacity of regulatory frameworks, and thus require integrated governance frameworks. We suggest sustainability—which gives equal consideration to the environment, economy, and society—as one framework for addressing complexity and uncertainty in the governance of emerging gene drive technologies for invasive species management. We explore the impacts of rodent gene drives on island environments, including potential conservation and restoration of island biodiversity. We outline considerations for rodent gene drives on island economies, including impacts on agricultural and tourism losses, and reductions in biosecurity costs. Finally, we address the social dimension as an essential space for deliberation that will be integral to evaluating the potential deployment of gene drive rodents on islands.
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Prowse TA, Adikusuma F, Cassey P, Thomas P, Ross JV. A Y-chromosome shredding gene drive for controlling pest vertebrate populations. eLife 2019; 8:41873. [PMID: 30767891 PMCID: PMC6398975 DOI: 10.7554/elife.41873] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 02/13/2019] [Indexed: 11/16/2022] Open
Abstract
Self-replicating gene drives that modify sex ratios or infer a fitness cost could be used to control populations of invasive alien species. The targeted deletion of Y sex chromosomes using CRISPR technology offers a new approach for sex bias that could be incorporated within gene-drive designs. We introduce a novel gene-drive strategy termed Y-CHromosome deletion using Orthogonal Programmable Endonucleases (Y-CHOPE), incorporating a programmable endonuclease that ‘shreds’ the Y chromosome, thereby converting XY males into fertile XO females. Firstly, we demonstrate that the CRISPR/Cas12a system can eliminate the Y chromosome in embryonic stem cells with high efficiency (c. 90%). Next, using stochastic, individual-based models of a pest mouse population, we show that a Y-shredding drive that progressively depletes the pool of XY males could effect population eradication through mate limitation. Our molecular and modeling data suggest that a Y-CHOPE gene drive could be a viable tool for vertebrate pest control.
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Affiliation(s)
- Thomas Aa Prowse
- School of Mathematical Sciences, The University of Adelaide, Adelaide, Australia
| | - Fatwa Adikusuma
- School of Medicine, The University of Adelaide, Adelaide, Australia.,South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Phillip Cassey
- The Centre for Applied Conservation Science, The University of Adelaide, Adelaide, Australia.,School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Paul Thomas
- School of Medicine, The University of Adelaide, Adelaide, Australia.,South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Joshua V Ross
- School of Mathematical Sciences, The University of Adelaide, Adelaide, Australia
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23
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Runge JN, Lindholm AK. Carrying a selfish genetic element predicts increased migration propensity in free-living wild house mice. Proc Biol Sci 2018; 285:20181333. [PMID: 30282651 PMCID: PMC6191700 DOI: 10.1098/rspb.2018.1333] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/10/2018] [Indexed: 12/22/2022] Open
Abstract
Life is built on cooperation between genes, which makes it vulnerable to parasitism. Selfish genetic elements that exploit this cooperation can achieve large fitness gains by increasing their transmission relative to the rest of the genome. This leads to counter-adaptations that generate unique selection pressures on the selfish genetic element. This arms race is similar to host-parasite coevolution, as some multi-host parasites alter the host's behaviour to increase the chance of transmission to the next host. Here, we ask if, similarly to these parasites, a selfish genetic element in house mice, the t haplotype, also manipulates host behaviour, specifically the host's migration propensity. Variants of the t that manipulate migration propensity could increase in fitness in a meta-population. We show that juvenile mice carrying the t haplotype were more likely to emigrate from and were more often found as migrants within a long-term free-living house mouse population. This result may have applied relevance as the t has been proposed as a basis for artificial gene drive systems for use in population control.
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Affiliation(s)
- Jan-Niklas Runge
- Department of Evolutionary Biology and Environmental Sciences, University of Zurich, CH-8057 Zurich, Switzerland
| | - Anna K Lindholm
- Department of Evolutionary Biology and Environmental Sciences, University of Zurich, CH-8057 Zurich, Switzerland
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24
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Wilkins KE, Prowse TAA, Cassey P, Thomas PQ, Ross JV. Pest demography critically determines the viability of synthetic gene drives for population control. Math Biosci 2018; 305:160-169. [PMID: 30219282 DOI: 10.1016/j.mbs.2018.09.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 08/10/2018] [Accepted: 09/06/2018] [Indexed: 12/20/2022]
Abstract
Synthetic gene drives offer a novel solution for the control of invasive alien species. CRISPR-based gene drives can positively bias their own inheritance, and comprise a DNA sequence that is replicated by homologous recombination. Since gene drives can be positioned to silence fertility or developmental genes, they could be used for population suppression. However, the production of resistant alleles following self-replication errors threatens the technology's viability for pest eradication in real-world applications. Further, a robust assessment of how pest demography impacts the expected progression of gene drives through populations is currently lacking. We used a deterministic, two-sex, birth-death model to investigate how demographic assumptions affect the efficiency of suppression drives for controlling invasive rodents on islands, for two different gene-drive strategies. We show that mass-action reproduction results in overly optimistic eradication outcomes when compared to the more realistic assumption of polygynous breeding. When polygyny was assumed, both gene-strategies failed due to the evolution of resistance unless a reproductive Allee effect (reduced reproductive rates at low population density) was also included; although model outcomes were highly sensitive to the strength of this effect. Increasing the size of the initial gene-drive introduction (up to 10% of carrying capacity) had little impact on population outcomes. Understanding the demography of a population targeted for eradication is critical before the viability of gene-drive suppression can be adequately assessed.
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Affiliation(s)
- Kym E Wilkins
- School of Mathematical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Thomas A A Prowse
- School of Mathematical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia.
| | - Phillip Cassey
- Centre for Applied Conservation Science and School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Paul Q Thomas
- The Robinson Research Institute and School of Medicine, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Joshua V Ross
- School of Mathematical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
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25
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Moro D, Byrne M, Kennedy M, Campbell S, Tizard M. Identifying knowledge gaps for gene drive research to control invasive animal species: The next CRISPR step. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2017.e00363] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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26
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Prowse TAA, Cassey P, Ross JV, Pfitzner C, Wittmann TA, Thomas P. Dodging silver bullets: good CRISPR gene-drive design is critical for eradicating exotic vertebrates. Proc Biol Sci 2017; 284:20170799. [PMID: 28794219 PMCID: PMC5563802 DOI: 10.1098/rspb.2017.0799] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/03/2017] [Indexed: 01/08/2023] Open
Abstract
Self-replicating gene drives that can spread deleterious alleles through animal populations have been promoted as a much needed but controversial 'silver bullet' for controlling invasive alien species. Homing-based drives comprise an endonuclease and a guide RNA (gRNA) that are replicated during meiosis via homologous recombination. However, their efficacy for controlling wild populations is threatened by inherent polymorphic resistance and the creation of resistance alleles via non-homologous end-joining (NHEJ)-mediated DNA repair. We used stochastic individual-based models to identify realistic gene-drive strategies capable of eradicating vertebrate pest populations (mice, rats and rabbits) on islands. One popular strategy, a sex-reversing drive that converts heterozygous females into sterile males, failed to spread and required the ongoing deployment of gene-drive carriers to achieve eradication. Under alternative strategies, multiplexed gRNAs could overcome inherent polymorphic resistance and were required for eradication success even when the probability of NHEJ was low. Strategies causing homozygotic embryonic non-viability or homozygotic female sterility produced high probabilities of eradication and were robust to NHEJ-mediated deletion of the DNA sequence between multiplexed endonuclease recognition sites. The latter two strategies also purged the gene drive when eradication failed, therefore posing lower long-term risk should animals escape beyond target islands. Multiplexing gRNAs will be necessary if this technology is to be useful for insular extirpation attempts; however, precise knowledge of homing rates will be required to design low-risk gene drives with high probabilities of eradication success.
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Affiliation(s)
- Thomas A A Prowse
- School of Mathematical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Phillip Cassey
- The Environment Institute and School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Joshua V Ross
- School of Mathematical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Chandran Pfitzner
- The Environment Institute and School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Talia A Wittmann
- The Environment Institute and School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Paul Thomas
- The Environment Institute and School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
- The Robinson Research Institute, The University of Adelaide, Adelaide, South Australia 5005, Australia
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27
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Kanavy D, Serr M. Sry Gene Drive for Rodent Control: Reply to Gemmell and Tompkins. Trends Ecol Evol 2017; 32:315-316. [PMID: 28389104 DOI: 10.1016/j.tree.2017.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 03/06/2017] [Accepted: 03/07/2017] [Indexed: 11/27/2022]
Affiliation(s)
- Dona Kanavy
- Department of Molecular and Cellular Medicine, Texas A&M University, College Station, TX 77843, USA.
| | - Megan Serr
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
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