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Ma S, Ni X, Chen S, Qiao X, Xu X, Chen W, Champer J, Huang J. A small-molecule approach to restore female sterility phenotype targeted by a homing suppression gene drive in the fruit pest Drosophila suzukii. PLoS Genet 2024; 20:e1011226. [PMID: 38578788 PMCID: PMC11023630 DOI: 10.1371/journal.pgen.1011226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 04/17/2024] [Accepted: 03/15/2024] [Indexed: 04/07/2024] Open
Abstract
CRISPR-based gene drives offer promising prospects for controlling disease-transmitting vectors and agricultural pests. A significant challenge for successful suppression-type drive is the rapid evolution of resistance alleles. One approach to mitigate the development of resistance involves targeting functionally constrained regions using multiple gRNAs. In this study, we constructed a 3-gRNA homing gene drive system targeting the recessive female fertility gene Tyrosine decarboxylase 2 (Tdc2) in Drosophila suzukii, a notorious fruit pest. Our investigation revealed only a low level of homing in the germline, but feeding octopamine restored the egg-laying defects in Tdc2 mutant females, allowing easier line maintenance than for other suppression drive targets. We tested the effectiveness of a similar system in Drosophila melanogaster and constructed additional split drive systems by introducing promoter-Cas9 transgenes to improve homing efficiency. Our findings show that genetic polymorphisms in wild populations may limit the spread of gene drive alleles, and the position effect profoundly influences Cas9 activity. Furthermore, this study highlights the potential of conditionally rescuing the female infertility caused by the gene drive, offering a valuable tool for the industrial-scale production of gene drive transgenic insects.
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Affiliation(s)
- Suhan Ma
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Xuyang Ni
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Shimin Chen
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | | | - Xuejiao Xu
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, Beijing, China
| | - Weizhe Chen
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, Beijing, China
- PTN program, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jackson Champer
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, Beijing, China
| | - Jia Huang
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
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2
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Janzen A, Pothula R, Sychla A, Feltman NR, Smanski MJ. Predicting thresholds for population replacement gene drives. BMC Biol 2024; 22:40. [PMID: 38369493 PMCID: PMC10875781 DOI: 10.1186/s12915-024-01823-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 01/10/2024] [Indexed: 02/20/2024] Open
Abstract
BACKGROUND Threshold-dependent gene drives (TDGDs) could be used to spread desirable traits through a population, and are likely to be less invasive and easier to control than threshold-independent gene drives. Engineered Genetic Incompatibility (EGI) is an extreme underdominance system previously demonstrated in Drosophila melanogaster that can function as a TDGD when EGI agents of both sexes are released into a wild-type population. RESULTS Here we use a single generation fitness assay to compare the fecundity, mating preferences, and temperature-dependent relative fitness to wild-type of two distinct genotypes of EGI agents. We find significant differences in the behavior/performance of these EGI agents that would not be predicted a priori based on their genetic design. We report a surprising temperature-dependent change in the predicted threshold for population replacement in an EGI agent that drives ectopic expression of the developmental morphogen pyramus. CONCLUSIONS The single-generation fitness assay presented here could reduce the amount of time required to estimate the threshold for TDGD strategies for which hybrid genotypes are inviable. Additionally, this work underscores the importance of empirical characterization of multiple engineered lines, as behavioral differences can arise in unique genotypes for unknown reasons.
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Affiliation(s)
- Anna Janzen
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, 55455, MN, USA
- Biotechnology Institute, University of Minnesota, Saint Paul, 55108, MN, USA
| | - Ratnasri Pothula
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, 55455, MN, USA
- Biotechnology Institute, University of Minnesota, Saint Paul, 55108, MN, USA
| | - Adam Sychla
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, 55455, MN, USA
- Biotechnology Institute, University of Minnesota, Saint Paul, 55108, MN, USA
| | - Nathan R Feltman
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, 55455, MN, USA
- Biotechnology Institute, University of Minnesota, Saint Paul, 55108, MN, USA
| | - Michael J Smanski
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, 55455, MN, USA.
- Biotechnology Institute, University of Minnesota, Saint Paul, 55108, MN, USA.
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3
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Awan MJA, Naqvi RZ, Amin I, Mansoor S. Gene drive in plants emerges from infancy. Trends Plant Sci 2024; 29:108-110. [PMID: 37863729 DOI: 10.1016/j.tplants.2023.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/03/2023] [Accepted: 10/05/2023] [Indexed: 10/22/2023]
Abstract
Selfish genetic elements (SGEs) display biased transmission to offspring. However, their breeding potential has remained obscure. Wang et al. recently reported a natural gene-drive system that can be harnessed to prevent hybrid incompatibility and to develop a synthetic gene-drive (SGD) system for crop improvement.
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Affiliation(s)
- Muhammad Jawad Akbar Awan
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences, Jhang Road, Faisalabad, Pakistan
| | - Rubab Zahra Naqvi
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences, Jhang Road, Faisalabad, Pakistan
| | - Imran Amin
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences, Jhang Road, Faisalabad, Pakistan
| | - Shahid Mansoor
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences, Jhang Road, Faisalabad, Pakistan; International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan.
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4
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D'Amato R, Taxiarchi C, Galardini M, Trusso A, Minuz RL, Grilli S, Somerville AGT, Shittu D, Khalil AS, Galizi R, Crisanti A, Simoni A, Müller R. Anti-CRISPR Anopheles mosquitoes inhibit gene drive spread under challenging behavioural conditions in large cages. Nat Commun 2024; 15:952. [PMID: 38296981 PMCID: PMC10830555 DOI: 10.1038/s41467-024-44907-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 01/10/2024] [Indexed: 02/02/2024] Open
Abstract
CRISPR-based gene drives have the potential to spread within populations and are considered as promising vector control tools. A doublesex-targeting gene drive was able to suppress laboratory Anopheles mosquito populations in small and large cages, and it is considered for field application. Challenges related to the field-use of gene drives and the evolving regulatory framework suggest that systems able to modulate or revert the action of gene drives, could be part of post-release risk-mitigation plans. In this study, we challenge an AcrIIA4-based anti-drive to inhibit gene drive spread in age-structured Anopheles gambiae population under complex feeding and behavioural conditions. A stochastic model predicts the experimentally-observed genotype dynamics in age-structured populations in medium-sized cages and highlights the necessity of large-sized cage trials. These experiments and experimental-modelling framework demonstrate the effectiveness of the anti-drive in different scenarios, providing further corroboration for its use in controlling the spread of gene drive in Anopheles.
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Affiliation(s)
- Rocco D'Amato
- Genetics and Ecology Research Centre, Polo of Genomics, Genetics and Biology (Polo GGB), Terni, Italy
| | | | - Marco Galardini
- Biological Design Center, Boston University, Boston, MA, USA
- Institute for Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, a joint venture between the Hannover Medical School (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School (MHH), Hannover, Germany
| | - Alessandro Trusso
- Genetics and Ecology Research Centre, Polo of Genomics, Genetics and Biology (Polo GGB), Terni, Italy
| | - Roxana L Minuz
- Genetics and Ecology Research Centre, Polo of Genomics, Genetics and Biology (Polo GGB), Terni, Italy
| | - Silvia Grilli
- Department of Life Sciences, Imperial College London, London, UK
| | | | - Dammy Shittu
- Department of Life Sciences, Imperial College London, London, UK
| | - Ahmad S Khalil
- Biological Design Center, Boston University, Boston, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Roberto Galizi
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Keele, UK
| | - Andrea Crisanti
- Department of Life Sciences, Imperial College London, London, UK
- Department of Molecular Medicine, University of Padova, Padua, Italy
| | - Alekos Simoni
- Genetics and Ecology Research Centre, Polo of Genomics, Genetics and Biology (Polo GGB), Terni, Italy.
- Department of Life Sciences, Imperial College London, London, UK.
| | - Ruth Müller
- Genetics and Ecology Research Centre, Polo of Genomics, Genetics and Biology (Polo GGB), Terni, Italy.
- Unit of Entomology, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
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5
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Anderson MAE, Gonzalez E, Edgington MP, Ang JXD, Purusothaman DK, Shackleford L, Nevard K, Verkuijl SAN, Harvey-Samuel T, Leftwich PT, Esvelt K, Alphey L. A multiplexed, confinable CRISPR/Cas9 gene drive can propagate in caged Aedes aegypti populations. Nat Commun 2024; 15:729. [PMID: 38272895 PMCID: PMC10810878 DOI: 10.1038/s41467-024-44956-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 01/11/2024] [Indexed: 01/27/2024] Open
Abstract
Aedes aegypti is the main vector of several major pathogens including dengue, Zika and chikungunya viruses. Classical mosquito control strategies utilizing insecticides are threatened by rising resistance. This has stimulated interest in new genetic systems such as gene drivesHere, we test the regulatory sequences from the Ae. aegypti benign gonial cell neoplasm (bgcn) homolog to express Cas9 and a separate multiplexing sgRNA-expressing cassette inserted into the Ae. aegypti kynurenine 3-monooxygenase (kmo) gene. When combined, these two elements provide highly effective germline cutting at the kmo locus and act as a gene drive. Our target genetic element drives through a cage trial population such that carrier frequency of the element increases from 50% to up to 89% of the population despite significant fitness costs to kmo insertions. Deep sequencing suggests that the multiplexing design could mitigate resistance allele formation in our gene drive system.
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Affiliation(s)
- Michelle A E Anderson
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0HN, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Estela Gonzalez
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0HN, UK
- Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK
| | - Matthew P Edgington
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0HN, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Joshua X D Ang
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0HN, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Deepak-Kumar Purusothaman
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0HN, UK
- MRC-University of Glasgow Centre for Virus Research, Henry Wellcome Building, 464 Bearsden Road, Glasgow, G61 1QH, UK
| | - Lewis Shackleford
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0HN, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Katherine Nevard
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0HN, UK
| | - Sebald A N Verkuijl
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0HN, UK
- Department of Biology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK
| | | | - Philip T Leftwich
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0HN, UK
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
| | - Kevin Esvelt
- Media Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Luke Alphey
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0HN, UK.
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK.
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6
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Olejarz JW, Nowak MA. Gene drives for the extinction of wild metapopulations. J Theor Biol 2024; 577:111654. [PMID: 37984587 DOI: 10.1016/j.jtbi.2023.111654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 09/15/2023] [Accepted: 10/31/2023] [Indexed: 11/22/2023]
Abstract
Population-suppressing gene drives may be capable of extinguishing wild populations, with proposed applications in conservation, agriculture, and public health. However, unintended and potentially disastrous consequences of release of drive-engineered individuals are extremely difficult to predict. We propose a model for the dynamics of a sex ratio-biasing drive, and using simulations, we show that failure of the suppression drive is often a natural outcome due to stochastic and spatial effects. We further demonstrate rock-paper-scissors dynamics among wild-type, drive-infected, and extinct populations that can persist for arbitrarily long times. Gene drive-mediated extinction of wild populations entails critical complications that lurk far beyond the reach of laboratory-based studies. Our findings help in addressing these challenges.
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Affiliation(s)
- Jason W Olejarz
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA; Department of Mathematics, Harvard University, Cambridge, MA, 02138, USA.
| | - Martin A Nowak
- Department of Mathematics, Harvard University, Cambridge, MA, 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
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7
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Meccariello A, Hou S, Davydova S, Fawcett JD, Siddall A, Leftwich PT, Krsticevic F, Papathanos PA, Windbichler N. Gene drive and genetic sex conversion in the global agricultural pest Ceratitis capitata. Nat Commun 2024; 15:372. [PMID: 38191463 PMCID: PMC10774415 DOI: 10.1038/s41467-023-44399-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 12/12/2023] [Indexed: 01/10/2024] Open
Abstract
Homing-based gene drives are recently proposed interventions promising the area-wide, species-specific genetic control of harmful insect populations. Here we characterise a first set of gene drives in a tephritid agricultural pest species, the Mediterranean fruit fly Ceratitis capitata (medfly). Our results show that the medfly is highly amenable to homing-based gene drive strategies. By targeting the medfly transformer gene, we also demonstrate how CRISPR-Cas9 gene drive can be coupled to sex conversion, whereby genetic females are transformed into fertile and harmless XX males. Given this unique malleability of sex determination, we modelled gene drive interventions that couple sex conversion and female sterility and found that such approaches could be effective and tolerant of resistant allele selection in the target population. Our results open the door for developing gene drive strains for the population suppression of the medfly and related tephritid pests by co-targeting female reproduction and shifting the reproductive sex ratio towards males. They demonstrate the untapped potential for gene drives to tackle agricultural pests in an environmentally friendly and economical way.
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Affiliation(s)
- Angela Meccariello
- Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK.
| | - Shibo Hou
- Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Serafima Davydova
- Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | | | - Alexandra Siddall
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Philip T Leftwich
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Flavia Krsticevic
- Department of Entomology, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel
| | - Philippos Aris Papathanos
- Department of Entomology, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel
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8
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Harris KD, Greenbaum G. Rescue by gene swamping as a gene drive deployment strategy. Cell Rep 2023; 42:113499. [PMID: 38039130 DOI: 10.1016/j.celrep.2023.113499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 10/05/2023] [Accepted: 11/13/2023] [Indexed: 12/03/2023] Open
Abstract
Gene drives are genetic constructs that can spread deleterious alleles with potential application to population suppression of harmful species. As gene drives can potentially spill over to other populations or species, control measures and fail-safe strategies must be considered. Gene drives can generate a rapid change in the population's genetic composition, leading to substantial demographic decline, processes that are expected to occur at a similar timescale during gene drive spread. We developed a gene drive model that combines evolutionary and demographic dynamics in a two-population setting. The model demonstrates how feedback between these dynamics generates additional outcomes to those generated by the evolutionary dynamics alone. We identify an outcome of particular interest where short-term suppression of the target population is followed by gene swamping and loss of the gene drive. This outcome can prevent spillover and is robust to the evolution of resistance, suggesting it may be suitable as a fail-safe strategy for gene drive deployment.
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Affiliation(s)
- Keith D Harris
- Department of Ecology, Evolution and Behavior, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
| | - Gili Greenbaum
- Department of Ecology, Evolution and Behavior, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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9
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Cohen J. 'Gene drive' may help fight viruses with viruses. Science 2023; 382:1337-1338. [PMID: 38127746 DOI: 10.1126/science.adn6357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
CRISPR-engineered herpesviruses can speed spread of genes to viral relatives in mice.
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10
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Green EI, Jaouen E, Klug D, Proveti Olmo R, Gautier A, Blandin S, Marois E. A population modification gene drive targeting both Saglin and Lipophorin impairs Plasmodium transmission in Anopheles mosquitoes. eLife 2023; 12:e93142. [PMID: 38051195 PMCID: PMC10786457 DOI: 10.7554/elife.93142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 11/14/2023] [Indexed: 12/07/2023] Open
Abstract
Lipophorin is an essential, highly expressed lipid transport protein that is secreted and circulates in insect hemolymph. We hijacked the Anopheles coluzzii Lipophorin gene to make it co-express a single-chain version of antibody 2A10, which binds sporozoites of the malaria parasite Plasmodium falciparum. The resulting transgenic mosquitoes show a markedly decreased ability to transmit Plasmodium berghei expressing the P. falciparum circumsporozoite protein to mice. To force the spread of this antimalarial transgene in a mosquito population, we designed and tested several CRISPR/Cas9-based gene drives. One of these is installed in, and disrupts, the pro-parasitic gene Saglin and also cleaves wild-type Lipophorin, causing the anti-malarial modified Lipophorin version to replace the wild type and hitch-hike together with the Saglin drive. Although generating drive-resistant alleles and showing instability in its gRNA-encoding multiplex array, the Saglin-based gene drive reached high levels in caged mosquito populations and efficiently promoted the simultaneous spread of the antimalarial Lipophorin::Sc2A10 allele. This combination is expected to decrease parasite transmission via two different mechanisms. This work contributes to the design of novel strategies to spread antimalarial transgenes in mosquitoes, and illustrates some expected and unexpected outcomes encountered when establishing a population modification gene drive.
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Affiliation(s)
- Emily I Green
- Inserm U1257, CNRS UPR9022, University of StrasbourgStrasbourgFrance
| | - Etienne Jaouen
- Inserm U1257, CNRS UPR9022, University of StrasbourgStrasbourgFrance
| | - Dennis Klug
- Inserm U1257, CNRS UPR9022, University of StrasbourgStrasbourgFrance
| | | | - Amandine Gautier
- Inserm U1257, CNRS UPR9022, University of StrasbourgStrasbourgFrance
| | - Stéphanie Blandin
- Inserm U1257, CNRS UPR9022, University of StrasbourgStrasbourgFrance
| | - Eric Marois
- Inserm U1257, CNRS UPR9022, University of StrasbourgStrasbourgFrance
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11
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Harvey-Samuel T, Feng X, Okamoto EM, Purusothaman DK, Leftwich PT, Alphey L, Gantz VM. CRISPR-based gene drives generate super-Mendelian inheritance in the disease vector Culex quinquefasciatus. Nat Commun 2023; 14:7561. [PMID: 37985762 PMCID: PMC10662442 DOI: 10.1038/s41467-023-41834-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 09/21/2023] [Indexed: 11/22/2023] Open
Abstract
Culex mosquitoes pose a significant public health threat as vectors for a variety of diseases including West Nile virus and lymphatic filariasis, and transmit pathogens threatening livestock, companion animals, and endangered birds. Rampant insecticide resistance makes controlling these mosquitoes challenging and necessitates the development of new control strategies. Gene drive technologies have made significant progress in other mosquito species, although similar advances have been lagging in Culex. Here we test a CRISPR-based homing gene drive for Culex quinquefasciatus, and show that the inheritance of two split-gene-drive transgenes, targeting different loci, are biased in the presence of a Cas9-expressing transgene although with modest efficiencies. Our findings extend the list of disease vectors where engineered homing gene drives have been demonstrated to include Culex alongside Anopheles and Aedes, and pave the way for future development of these technologies to control Culex mosquitoes.
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Affiliation(s)
- Tim Harvey-Samuel
- Arthropod Genetics Group, The Pirbright Institute, Woking, GU24 0NF, UK
| | - Xuechun Feng
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA.
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Guangdong, 518106, Shenzhen, China.
| | - Emily M Okamoto
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Deepak-Kumar Purusothaman
- Arthropod Genetics Group, The Pirbright Institute, Woking, GU24 0NF, UK
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Philip T Leftwich
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Luke Alphey
- Arthropod Genetics Group, The Pirbright Institute, Woking, GU24 0NF, UK.
- Biology Department, University of York, York, YO10 5DD, UK.
| | - Valentino M Gantz
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA.
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Bennett JB, Wu SL, Chennuri PR, Myles KM, Ndeffo-Mbah ML. Expansions to the MGDrivE suite for simulating the efficacy of novel gene-drive constructs in the control of mosquito-borne diseases. BMC Res Notes 2023; 16:258. [PMID: 37798614 PMCID: PMC10557238 DOI: 10.1186/s13104-023-06533-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 09/25/2023] [Indexed: 10/07/2023] Open
Abstract
OBJECTIVE The MGDrivE (MGDrivE 1 and MGDrivE 2) modeling framework provides a flexible and expansive environment for testing the efficacy of novel gene-drive constructs for the control of mosquito-borne diseases. However, the existing model framework did not previously support several features necessary to simulate some types of intervention strategies. Namely, current MGDrivE versions do not permit modeling of small molecule inducible systems for controlling gene expression in gene drive designs or the inheritance patterns of self-eliminating gene drive mechanisms. RESULTS Here, we demonstrate a new MGDrivE 2 module that permits the simulation of gene drive strategies incorporating small molecule-inducible systems and self-eliminating gene drive mechanisms. Additionally, we also implemented novel sparsity-aware sampling algorithms for improved computational efficiency in MGDrivE 2 and supplied an analysis and plotting function applicable to the outputs of MGDrivE 1 and MGDrivE 2.
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Affiliation(s)
| | - Sean L Wu
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA
| | - Pratima R Chennuri
- Department of Entomology, Texas A & M University, College Station, TX, 77843, USA
- Future Fields, Edmonton, AB, T5H 0L5, Canada
| | - Kevin M Myles
- Department of Entomology, Texas A & M University, College Station, TX, 77843, USA
| | - Martial L Ndeffo-Mbah
- Department of Integrative Biosciences, Texas A&M University, College Station, TX, 77843, USA.
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Lester PJ, O'Sullivan D, Perry GLW. Gene drives for invasive wasp control: Extinction is unlikely, with suppression dependent on dispersal and growth rates. Ecol Appl 2023; 33:e2912. [PMID: 37615220 DOI: 10.1002/eap.2912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 06/28/2023] [Accepted: 07/14/2023] [Indexed: 08/25/2023]
Abstract
Gene drives offer a potentially revolutionary method for pest control over large spatial extents. These genetic modifications spread deleterious variants through a population and have been proposed as methods for pest suppression or even eradication. We examined the influence of local dispersal, long-distance and/or human-mediated dispersal, and variation in population growth on the success of a gene drive for the control of invasive social wasps (Vespula vulgaris). Our simulations incorporated a spatially realistic environment containing variable habitat quality in New Zealand. Pest eradication was not observed, except in extreme and unrealistic scenarios of constant, widespread, and spatially intense releases of genetically modified individuals every year for decades. Instead, the regional persistence of genetically modified and wild-type wasps was predicted. Simulations using spatially homogeneous versus realistic landscapes (incorporating uninhabitable areas and dispersal barriers) showed little difference in overall population dynamics. Overall, little impact on wasp abundance was observed in the first 15 years after introduction. After 25 years, populations were suppressed to levels <95% of starting populations. Populations exhibited "chase dynamics" with population cycles in space, with local extinction occurring in some areas while wasps became abundant in others. Increasing the wasps' local dispersal distance increased the spatial and temporal variability of the occupied area and population suppression. Varying levels of human-associated long-distance dispersal had little effect on population dynamics. Increasing intrinsic population growth rates interacted with local dispersal to cause higher mean populations and substantially higher levels of variation in population suppression and the total amount of landscape occupied. Gene drives appear unlikely to cause a rapid and widespread extinction of this and probably other pests but could offer long-term and cost-effective methods of pest suppression. The predicted level of <95% pest suppression would substantially reduce the predation pressure and competitive interactions of this invasive wasp on native species. However, the predicted long-term persistence of genetically modified pests will influence the ethics and likelihood of using gene drives for pest control, especially given concerns that modified wasps would eventually be transported back to their home range.
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Affiliation(s)
- Philip J Lester
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - David O'Sullivan
- School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - George L W Perry
- School of Environment, University of Auckland, Auckland, New Zealand
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14
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Wolf S, Collatz J, Enkerli J, Widmer F, Romeis J. Assessing potential hybridization between a hypothetical gene drive-modified Drosophila suzukii and nontarget Drosophila species. Risk Anal 2023; 43:1921-1932. [PMID: 36693350 DOI: 10.1111/risa.14096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Abstract
Genetically engineered gene drives (geGD) are potentially powerful tools for suppressing or even eradicating populations of pest insects. Before living geGD insects can be released into the environment, they must pass an environmental risk assessment to ensure that their release will not cause unacceptable harm to non-targeted entities of the environment. A key research question concerns the likelihood that nontarget species will acquire the functional GD elements; such acquisition could lead to reduced abundance or loss of those species and to a disruption of the ecosystem services they provide. The main route for gene flow is through hybridization between the geGD insect strain and closely related species that co-occur in the area of release and its expected dispersal. Using the invasive spotted-wing drosophila, Drosophila suzukii, as a case study, we provide a generally applicable strategy on how a combination of interspecific hybridization experiments, behavioral observations, and molecular genetic analyses can be used to assess the potential for hybridization.
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Affiliation(s)
- Sarah Wolf
- Research Division Agroecology and Environment, Agroscope, Zürich, Switzerland
- Institute for Plant Sciences, University of Bern, Bern, Switzerland
| | - Jana Collatz
- Research Division Agroecology and Environment, Agroscope, Zürich, Switzerland
| | - Jürg Enkerli
- Molecular Ecology, Agroscope, Zürich, Switzerland
| | | | - Jörg Romeis
- Research Division Agroecology and Environment, Agroscope, Zürich, Switzerland
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15
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Medina RF, Kuzma J. Engineered and natural gene drives: mechanistically the same, yet not same in kind. Nat Commun 2023; 14:5994. [PMID: 37752157 PMCID: PMC10522694 DOI: 10.1038/s41467-023-41727-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 09/18/2023] [Indexed: 09/28/2023] Open
Affiliation(s)
- Raul F Medina
- Department of Entomology, Texas A&M University, College Station, TX, USA.
| | - Jennifer Kuzma
- Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC, USA
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16
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Kim J, Harris KD, Kim IK, Shemesh S, Messer PW, Greenbaum G. Incorporating ecology into gene drive modelling. Ecol Lett 2023; 26 Suppl 1:S62-S80. [PMID: 37840022 DOI: 10.1111/ele.14194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 02/13/2023] [Accepted: 02/15/2023] [Indexed: 10/17/2023]
Abstract
Gene drive technology, in which fast-spreading engineered drive alleles are introduced into wild populations, represents a promising new tool in the fight against vector-borne diseases, agricultural pests and invasive species. Due to the risks involved, gene drives have so far only been tested in laboratory settings while their population-level behaviour is mainly studied using mathematical and computational models. The spread of a gene drive is a rapid evolutionary process that occurs over timescales similar to many ecological processes. This can potentially generate strong eco-evolutionary feedback that could profoundly affect the dynamics and outcome of a gene drive release. We, therefore, argue for the importance of incorporating ecological features into gene drive models. We describe the key ecological features that could affect gene drive behaviour, such as population structure, life-history, environmental variation and mode of selection. We review previous gene drive modelling efforts and identify areas where further research is needed. As gene drive technology approaches the level of field experimentation, it is crucial to evaluate gene drive dynamics, potential outcomes, and risks realistically by including ecological processes.
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Affiliation(s)
- Jaehee Kim
- Department of Computational Biology, Cornell University, Ithaca, New York, USA
| | - Keith D Harris
- Department of Ecology, Evolution and Behavior, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Isabel K Kim
- Department of Computational Biology, Cornell University, Ithaca, New York, USA
| | - Shahar Shemesh
- Department of Ecology, Evolution and Behavior, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Philipp W Messer
- Department of Computational Biology, Cornell University, Ithaca, New York, USA
| | - Gili Greenbaum
- Department of Ecology, Evolution and Behavior, The Hebrew University of Jerusalem, Jerusalem, Israel
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17
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Wang C, Wang J, Lu J, Xiong Y, Zhao Z, Yu X, Zheng X, Li J, Lin Q, Ren Y, Hu Y, He X, Li C, Zeng Y, Miao R, Guo M, Zhang B, Zhu Y, Zhang Y, Tang W, Wang Y, Hao B, Wang Q, Cheng S, He X, Yao B, Gao J, Zhu X, Yu H, Wang Y, Sun Y, Zhou C, Dong H, Ma X, Guo X, Liu X, Tian Y, Liu S, Wang C, Cheng Z, Jiang L, Zhou J, Guo H, Jiang L, Tao D, Chai J, Zhang W, Wang H, Wu C, Wan J. A natural gene drive system confers reproductive isolation in rice. Cell 2023; 186:3577-3592.e18. [PMID: 37499659 DOI: 10.1016/j.cell.2023.06.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 02/02/2023] [Accepted: 06/28/2023] [Indexed: 07/29/2023]
Abstract
Hybrid sterility restricts the utilization of superior heterosis of indica-japonica inter-subspecific hybrids. In this study, we report the identification of RHS12, a major locus controlling male gamete sterility in indica-japonica hybrid rice. We show that RHS12 consists of two genes (iORF3/DUYAO and iORF4/JIEYAO) that confer preferential transmission of the RHS12-i type male gamete into the progeny, thereby forming a natural gene drive. DUYAO encodes a mitochondrion-targeted protein that interacts with OsCOX11 to trigger cytotoxicity and cell death, whereas JIEYAO encodes a protein that reroutes DUYAO to the autophagosome for degradation via direct physical interaction, thereby detoxifying DUYAO. Evolutionary trajectory analysis reveals that this system likely formed de novo in the AA genome Oryza clade and contributed to reproductive isolation (RI) between different lineages of rice. Our combined results provide mechanistic insights into the genetic basis of RI as well as insights for strategic designs of hybrid rice breeding.
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Affiliation(s)
- Chaolong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jian Wang
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jiayu Lu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yehui Xiong
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhigang Zhao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaowen Yu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaoming Zheng
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jing Li
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Qibing Lin
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yulong Ren
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yang Hu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaodong He
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chao Li
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yonglun Zeng
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Rong Miao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Mali Guo
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Bosen Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ying Zhu
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Yunhui Zhang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Weijie Tang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yunlong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Benyuan Hao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Qiming Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Siqi Cheng
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaojuan He
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Bowen Yao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Junwen Gao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xufei Zhu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Hao Yu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yan Sun
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chunlei Zhou
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Hui Dong
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaoding Ma
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiuping Guo
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xi Liu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yunlu Tian
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Shijia Liu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chunming Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhijun Cheng
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Ling Jiang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Jiawu Zhou
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Huishan Guo
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Liwen Jiang
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Dayun Tao
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Jijie Chai
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Wei Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Haiyang Wang
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Chuanyin Wu
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Jianmin Wan
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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18
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de Graeff N, Pirson I, van der Graaf R, Bredenoord AL, Jongsma KR. The boundary problem: Defining and delineating the community in field trials with gene drive organisms. Bioethics 2023; 37:600-609. [PMID: 37133893 DOI: 10.1111/bioe.13165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 03/14/2023] [Accepted: 04/04/2023] [Indexed: 05/04/2023]
Abstract
Despite widespread and worldwide efforts to eradicate vector-borne diseases such as malaria, these diseases continue to have an enormous negative impact on public health. For this reason, scientists are working on novel control strategies, such as gene drive technologies (GDTs). As GDT research advances, researchers are contemplating the potential next step of conducting field trials. An important point of discussion regarding these field trials relates to who should be informed, consulted, and involved in decision-making about their design and launch. It is generally argued that community members have a particularly strong claim to be engaged, and yet, disagreement and lack of clarity exist about how this "community" should be defined and delineated. In this paper, we shed light on this "boundary problem": the problem of determining how boundaries of inclusion and exclusion in (GDT) community engagement should be drawn. As our analysis demonstrates, the process of defining and delineating a community is itself normative. First, we explicate why it is important to define and delineate the community. Second, we demonstrate that different definitions of community are used and intermingled in the debate on GDTs, and argue in favor of distinguishing geographical, affected, cultural, and political communities. Finally, we propose initial guidance for deciding who should (not) be engaged in decision-making about GDT field trials, by arguing that the definition and delineation of the community should depend on the rationale for engagement and that the characteristics of the community itself can guide the effective design of community engagement strategies.
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Affiliation(s)
- Nienke de Graeff
- Department of Bioethics & Health Humanities, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
- Department of Medical Ethics & Health Law, Leiden University Medical Center, Leiden University, Leiden, The Netherlands
| | | | - Rieke van der Graaf
- Department of Bioethics & Health Humanities, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Annelien L Bredenoord
- Department of Bioethics & Health Humanities, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
- Erasmus School of Philosophy, Erasmus University, Rotterdam, The Netherlands
| | - Karin R Jongsma
- Department of Bioethics & Health Humanities, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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19
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James SL, O'Brochta DA, Randazzo F, Akbari OS. A gene drive is a gene drive: the debate over lumping or splitting definitions. Nat Commun 2023; 14:1749. [PMID: 36991021 PMCID: PMC10060380 DOI: 10.1038/s41467-023-37483-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 03/20/2023] [Indexed: 03/31/2023] Open
Affiliation(s)
- Stephanie L James
- Foundation for the National Institutes of Health, North Bethesda, MD, 20852, USA
| | - David A O'Brochta
- Foundation for the National Institutes of Health, North Bethesda, MD, 20852, USA
| | | | - Omar S Akbari
- University of California San Diego, La Jolla, CA, 92093, USA.
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20
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Li J, Champer J. Harnessing Wolbachia cytoplasmic incompatibility alleles for confined gene drive: A modeling study. PLoS Genet 2023; 19:e1010591. [PMID: 36689491 PMCID: PMC9894560 DOI: 10.1371/journal.pgen.1010591] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 02/02/2023] [Accepted: 12/21/2022] [Indexed: 01/24/2023] Open
Abstract
Wolbachia are maternally-inherited bacteria, which can spread rapidly in populations by manipulating reproduction. cifA and cifB are genes found in Wolbachia phage that are responsible for cytoplasmic incompatibility, the most common type of Wolbachia reproductive interference. In this phenomenon, no viable offspring are produced when a male with both cifA and cifB (or just cifB in some systems) mates with a female lacking cifA. Utilizing this feature, we propose new types of toxin-antidote gene drives that can be constructed with only these two genes in an insect genome, instead of the whole Wolbachia bacteria. By using both mathematical and simulation models, we found that a drive containing cifA and cifB together creates a confined drive with a moderate to high introduction threshold. When introduced separately, they act as a self-limiting drive. We observed that the performance of these drives is substantially influenced by various ecological parameters and drive characteristics. Extending our models to continuous space, we found that the drive individual release distribution has a critical impact on drive persistence. Our results suggest that these new types of drives based on Wolbachia transgenes are safe and flexible candidates for genetic modification of populations.
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Affiliation(s)
- Jiahe Li
- Center for Bioinformatics, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Jackson Champer
- Center for Bioinformatics, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
- * E-mail:
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21
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Anderson MAE, Gonzalez E, Ang JXD, Shackleford L, Nevard K, Verkuijl SAN, Edgington MP, Harvey-Samuel T, Alphey L. Closing the gap to effective gene drive in Aedes aegypti by exploiting germline regulatory elements. Nat Commun 2023; 14:338. [PMID: 36670107 PMCID: PMC9860013 DOI: 10.1038/s41467-023-36029-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 01/13/2023] [Indexed: 01/22/2023] Open
Abstract
CRISPR/Cas9-based homing gene drives have emerged as a potential new approach to mosquito control. While attempts have been made to develop such systems in Aedes aegypti, none have been able to match the high drive efficiency observed in Anopheles species. Here we generate Ae. aegypti transgenic lines expressing Cas9 using germline-specific regulatory elements and assess their ability to bias inheritance of an sgRNA-expressing element (kmosgRNAs). Four shu-Cas9 and one sds3-Cas9 isolines can significantly bias the inheritance of kmosgRNAs, with sds3G1-Cas9 causing the highest average inheritance of ~86% and ~94% from males and females carrying both elements outcrossed to wild-type, respectively. Our mathematical model demonstrates that sds3G1-Cas9 could enable the spread of the kmosgRNAs element to either reach a higher (by ~15 percentage point) maximum carrier frequency or to achieve similar maximum carrier frequency faster (by 12 generations) when compared to two other established split drive systems.
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Affiliation(s)
- Michelle A E Anderson
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Estela Gonzalez
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Joshua X D Ang
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Lewis Shackleford
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Katherine Nevard
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Sebald A N Verkuijl
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
- Mathematical Ecology Research Group, Department of Biology, University of Oxford, 11a Mansfield Road, Oxford, OX13SZ, UK
| | - Matthew P Edgington
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Tim Harvey-Samuel
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
| | - Luke Alphey
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK.
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK.
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22
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Taitingfong RI, Triplett C, Vásquez VN, Rajagopalan RM, Raban R, Roberts A, Terradas G, Baumgartner B, Emerson C, Gould F, Okumu F, Schairer CE, Bossin HC, Buchman L, Campbell KJ, Clark A, Delborne J, Esvelt K, Fisher J, Friedman RM, Gronvall G, Gurfield N, Heitman E, Kofler N, Kuiken T, Kuzma J, Manrique-Saide P, Marshall JM, Montague M, Morrison AC, Opesen CC, Phelan R, Piaggio A, Quemada H, Rudenko L, Sawadogo N, Smith R, Tuten H, Ullah A, Vorsino A, Windbichler N, Akbari OS, Long K, Lavery JV, Evans SW, Tountas K, Bloss CS. Exploring the value of a global gene drive project registry. Nat Biotechnol 2023; 41:9-13. [PMID: 36522496 DOI: 10.1038/s41587-022-01591-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Riley I Taitingfong
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla, CA, USA
| | - Cynthia Triplett
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla, CA, USA
- Center for Empathy and Technology, Institute for Empathy and Compassion, University of California, San Diego, La Jolla, CA, USA
| | - Váleri N Vásquez
- Energy and Resources Group, Rausser College of Natural Resources, University of California, Berkeley, Berkeley, CA, USA
- Department of Electrical Engineering and Computer Sciences, College of Engineering, University of California, Berkeley, Berkeley, CA, USA
| | - Ramya M Rajagopalan
- Center for Empathy and Technology, Institute for Empathy and Compassion, University of California, San Diego, La Jolla, CA, USA
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla, CA, USA
| | - Robyn Raban
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, USA
| | - Aaron Roberts
- Institute on Ethics and Policy for Innovation, McMaster University, Hamilton, Ontario, Canada
| | - Gerard Terradas
- Department of Entomology, the Center for Infectious Disease Dynamics and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | | | - Claudia Emerson
- Institute on Ethics and Policy for Innovation, McMaster University, Hamilton, Ontario, Canada
| | - Fred Gould
- Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC, USA
| | - Fredros Okumu
- Environmental Health and Ecological Science Department, Ifakara Health Institute, Ifakara, Tanzania
| | - Cynthia E Schairer
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla, CA, USA
| | - Hervé C Bossin
- Medical Entomology Laboratory, William A. Robinson Polynesian Research Center, Institut Louis Malardé, Papeete, Tahiti, French Polynesia
| | - Leah Buchman
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | | | - Anna Clark
- Department of Anatomy, University of Otago, Dunedin, Aotearoa New Zealand
| | - Jason Delborne
- Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC, USA
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, USA
| | - Kevin Esvelt
- Media Lab, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Joshua Fisher
- Pacific Islands Fish and Wildlife Office, United States Fish and Wildlife Service, Honolulu, HI, USA
| | | | - Gigi Gronvall
- Johns Hopkins Center for Health Security and Department of Environmental Health and Engineering, Baltimore, MD, USA
- Bloomberg School of Public Health, Johns Hopkins, Baltimore, MD, USA
| | - Nikos Gurfield
- Vector Control Program, Department of Environmental Health and Quality, County of San Diego, San Diego, CA, USA
| | - Elizabeth Heitman
- Program in Ethics in Science and Medicine, University of Texas Southwestern, Dallas, TX, USA
| | - Natalie Kofler
- Scientific Citizenship Initiative, Harvard Medical School, Boston, MA, USA
| | - Todd Kuiken
- Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC, USA
| | - Jennifer Kuzma
- Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC, USA
- School of Public and International Affairs, North Carolina State University, Raleigh, NC, USA
| | - Pablo Manrique-Saide
- Laboratorio para el Control Biológico de Aedes aegypti, Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, México
| | - John M Marshall
- Divisions of Biostatistics & Epidemiology, School of Public Health, UC Berkeley, Berkeley, CA, USA
- Innovative Genomics Institute, UC Berkeley, Berkeley, CA, USA
| | | | - Amy C Morrison
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - Chris C Opesen
- Department of Sociology and Anthropology, School of Social Sciences, Makerere University, Kampala, Uganda
| | | | - Antoinette Piaggio
- Animal and Plant Health Inspection Service, Wildlife Services, United States Department of Agriculture National Wildlife Research Center, Fort Collins, CO, USA
| | - Hector Quemada
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, USA
| | - Larisa Rudenko
- Massachusetts Institute of Technology, Cambridge, MA, USA
- BioPolicy Solutions, LLC, Cambridge, MA, USA
| | | | - Robert Smith
- Science, Technology & Innovation Studies, School of Social & Political Science, The University of Edinburgh, Edinburgh, UK
| | - Holly Tuten
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Anika Ullah
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Adam Vorsino
- Pacific Islands Fish and Wildlife Office, United States Fish and Wildlife Service, Honolulu, HI, USA
| | | | - Omar S Akbari
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, USA
| | - Kanya Long
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla, CA, USA
| | - James V Lavery
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
- Center for Ethics, Emory University, Atlanta, GA, USA
| | - Sam Weiss Evans
- Program on Science, Technology & Society, Harvard University, Cambridge, MA, USA
| | - Karen Tountas
- GeneConvene Global Collaborative, Science Division, Foundation for the National Institutes of Health, North Bethesda, MD, USA
| | - Cinnamon S Bloss
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla, CA, USA.
- Center for Empathy and Technology, Institute for Empathy and Compassion, University of California, San Diego, La Jolla, CA, USA.
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23
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Geci R, Willis K, Burt A. Gene drive designs for efficient and localisable population suppression using Y-linked editors. PLoS Genet 2022; 18:e1010550. [PMID: 36574454 PMCID: PMC9829173 DOI: 10.1371/journal.pgen.1010550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 01/09/2023] [Accepted: 11/29/2022] [Indexed: 12/28/2022] Open
Abstract
The sterile insect technique (SIT) has been successful in controlling some pest species but is not practicable for many others due to the large number of individuals that need to be reared and released. Previous computer modelling has demonstrated that the release of males carrying a Y-linked editor that kills or sterilises female descendants could be orders of magnitude more efficient than SIT while still remaining spatially restricted, particularly if combined with an autosomal sex distorter. In principle, further gains in efficiency could be achieved by using a self-propagating double drive design, in which each of the two components (the Y-linked editor and the sex ratio distorter) boosted the transmission of the other. To better understand the expected dynamics and impact of releasing constructs of this new design we have analysed a deterministic population genetic and population dynamic model. Our modelling demonstrates that this design can suppress a population from very low release rates, with no invasion threshold. Importantly, the design can work even if homing rates are low and sex chromosomes are silenced at meiosis, potentially expanding the range of species amenable to such control. Moreover, the predicted dynamics and impacts can be exquisitely sensitive to relatively small (e.g., 25%) changes in allele frequencies in the target population, which could be exploited for sequence-based population targeting. Analysis of published Anopheles gambiae genome sequences indicates that even for weakly differentiated populations with an FST of 0.02 there may be thousands of suitably differentiated genomic sites that could be used to restrict the spread and impact of a release. Our proposed design, which extends an already promising development pathway based on Y-linked editors, is therefore a potentially useful addition to the menu of options for genetic biocontrol.
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Affiliation(s)
- René Geci
- Dept. of Life Sciences, Imperial College London, Silwood Park, United Kingdom
| | - Katie Willis
- Dept. of Life Sciences, Imperial College London, Silwood Park, United Kingdom
| | - Austin Burt
- Dept. of Life Sciences, Imperial College London, Silwood Park, United Kingdom
- * E-mail:
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24
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Abstract
Population suppression is an effective way for controlling insect pests and disease vectors, which cause significant damage to crop and spread contagious diseases to plants, animals and humans. Gene drive systems provide innovative opportunities for the insect pests population suppression by driving genes that impart fitness costs on populations of pests or disease vectors. Different gene-drive systems have been developed in insects and applied for their population suppression. Here, different categories of gene drives such as meiotic drive (MD), under-dominance (UD), homing endonuclease-based gene drive (HEGD) and especially the CRISPR/Cas9-based gene drive (CCGD) were reviewed, including the history, types, process and mechanisms. Furthermore, the advantages and limitations of applying different gene-drive systems to suppress the insect population were also summarized. This review provides a foundation for developing a specific gene-drive system for insect population suppression.
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Affiliation(s)
- Muhammad Asad
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China
- Key Laboratory of Green Pest Control, Fujian Province University, Fuzhou 350002, China
| | - Dan Liu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China
- Key Laboratory of Green Pest Control, Fujian Province University, Fuzhou 350002, China
| | - Jing Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China
- Key Laboratory of Green Pest Control, Fujian Province University, Fuzhou 350002, China
| | - Guang Yang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China
- Key Laboratory of Green Pest Control, Fujian Province University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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25
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Reid W, Williams AE, Sanchez-Vargas I, Lin J, Juncu R, Olson KE, Franz AWE. Assessing single-locus CRISPR/Cas9-based gene drive variants in the mosquito Aedes aegypti via single-generation crosses and modeling. G3 (Bethesda) 2022; 12:jkac280. [PMID: 36250791 PMCID: PMC9713460 DOI: 10.1093/g3journal/jkac280] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 10/09/2022] [Indexed: 07/29/2023]
Abstract
The yellow fever mosquito Aedes aegypti is a major vector of arthropod-borne viruses, including dengue, chikungunya, and Zika viruses. A novel approach to mitigate arboviral infections is to generate mosquitoes refractory to infection by overexpressing antiviral effector molecules. Such an approach requires a mechanism to spread these antiviral effectors through a population, for example, by using CRISPR/Cas9-based gene drive systems. Critical to the design of a single-locus autonomous gene drive is that the selected genomic locus is amenable to both gene drive and appropriate expression of the antiviral effector. In our study, we used reverse engineering to target 2 intergenic genomic loci, which had previously shown to be highly permissive for antiviral effector gene expression, and we further investigated the use of 3 promoters (nanos, β2-tubulin, or zpg) for Cas9 expression. We then quantified the accrual of insertions or deletions (indels) after single-generation crossings, measured maternal effects, and assessed fitness costs associated with various transgenic lines to model the rate of gene drive fixation. Overall, MGDrivE modeling suggested that when an autonomous gene drive is placed into an intergenic locus, the gene drive system will eventually be blocked by the accrual of gene drive blocking resistance alleles and ultimately be lost in the population. Moreover, while genomic locus and promoter selection were critically important for the initial establishment of the autonomous gene drive, it was the fitness of the gene drive line that most strongly influenced the persistence of the gene drive in the simulated population. As such, we propose that when autonomous CRISPR/Cas9-based gene drive systems are anchored in an intergenic locus, they temporarily result in a strong population replacement effect, but as gene drive-blocking indels accrue, the gene drive becomes exhausted due to the fixation of CRISPR resistance alleles.
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Affiliation(s)
| | | | - Irma Sanchez-Vargas
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Jingyi Lin
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
| | - Rucsanda Juncu
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
| | - Ken E Olson
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Alexander W E Franz
- Corresponding author: Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA.
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26
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Verkuijl SAN, Gonzalez E, Li M, Ang JXD, Kandul NP, Anderson MAE, Akbari OS, Bonsall MB, Alphey L. A CRISPR endonuclease gene drive reveals distinct mechanisms of inheritance bias. Nat Commun 2022; 13:7145. [PMID: 36414618 PMCID: PMC9681865 DOI: 10.1038/s41467-022-34739-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 11/04/2022] [Indexed: 11/24/2022] Open
Abstract
CRISPR/Cas gene drives can bias transgene inheritance through different mechanisms. Homing drives are designed to replace a wild-type allele with a copy of a drive element on the homologous chromosome. In Aedes aegypti, the sex-determining locus is closely linked to the white gene, which was previously used as a target for a homing drive element (wGDe). Here, through an analysis using this linkage we show that in males inheritance bias of wGDe did not occur by homing, rather through increased propagation of the donor drive element. We test the same wGDe drive element with transgenes expressing Cas9 with germline regulatory elements sds3, bgcn, and nup50. We only find inheritance bias through homing, even with the identical nup50-Cas9 transgene. We propose that DNA repair outcomes may be more context dependent than anticipated and that other previously reported homing drives may, in fact, bias their inheritance through other mechanisms.
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Affiliation(s)
- Sebald A N Verkuijl
- Mathematical Ecology Research Group, Department of Biology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
| | - Estela Gonzalez
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Ming Li
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Joshua X D Ang
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Nikolay P Kandul
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Michelle A E Anderson
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Omar S Akbari
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Michael B Bonsall
- Mathematical Ecology Research Group, Department of Biology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK
| | - Luke Alphey
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, UK.
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK.
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27
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Hoermann A, Habtewold T, Selvaraj P, Del Corsano G, Capriotti P, Inghilterra MG, Kebede TM, Christophides GK, Windbichler N. Gene drive mosquitoes can aid malaria elimination by retarding Plasmodium sporogonic development. Sci Adv 2022; 8:eabo1733. [PMID: 36129981 PMCID: PMC9491717 DOI: 10.1126/sciadv.abo1733] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Gene drives hold promise for the genetic control of malaria vectors. The development of vector population modification strategies hinges on the availability of effector mechanisms impeding parasite development in transgenic mosquitoes. We augmented a midgut gene of the malaria mosquito Anopheles gambiae to secrete two exogenous antimicrobial peptides, magainin 2 and melittin. This small genetic modification, capable of efficient nonautonomous gene drive, hampers oocyst development in both Plasmodium falciparum and Plasmodium berghei. It delays the release of infectious sporozoites, while it simultaneously reduces the life span of homozygous female transgenic mosquitoes. Modeling the spread of this modification using a large-scale agent-based model of malaria epidemiology reveals that it can break the cycle of disease transmission across a range of transmission intensities.
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Affiliation(s)
- Astrid Hoermann
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Tibebu Habtewold
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Prashanth Selvaraj
- Institute for Disease Modeling, Bill and Melinda Gates Foundation, Seattle, WA 98109, USA
| | | | - Paolo Capriotti
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | | | - Temesgen M. Kebede
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - George K. Christophides
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
- Corresponding author. (G.K.C.); (N.W.)
| | - Nikolai Windbichler
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
- Corresponding author. (G.K.C.); (N.W.)
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28
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Langmüller AM, Champer J, Lapinska S, Xie L, Metzloff M, Champer SE, Liu J, Xu Y, Du J, Clark AG, Messer PW. Fitness effects of CRISPR endonucleases in Drosophila melanogaster populations. eLife 2022; 11:e71809. [PMID: 36135925 PMCID: PMC9545523 DOI: 10.7554/elife.71809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/08/2022] [Indexed: 11/13/2022] Open
Abstract
Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 provides a highly efficient and flexible genome editing technology with numerous potential applications ranging from gene therapy to population control. Some proposed applications involve the integration of CRISPR/Cas9 endonucleases into an organism's genome, which raises questions about potentially harmful effects to the transgenic individuals. One example for which this is particularly relevant are CRISPR-based gene drives conceived for the genetic alteration of entire populations. The performance of such drives can strongly depend on fitness costs experienced by drive carriers, yet relatively little is known about the magnitude and causes of these costs. Here, we assess the fitness effects of genomic CRISPR/Cas9 expression in Drosophila melanogaster cage populations by tracking allele frequencies of four different transgenic constructs that allow us to disentangle 'direct' fitness costs due to the integration, expression, and target-site activity of Cas9, from fitness costs due to potential off-target cleavage. Using a maximum likelihood framework, we find that a model with no direct fitness costs but moderate costs due to off-target effects fits our cage data best. Consistent with this, we do not observe fitness costs for a construct with Cas9HF1, a high-fidelity version of Cas9. We further demonstrate that using Cas9HF1 instead of standard Cas9 in a homing drive achieves similar drive conversion efficiency. These results suggest that gene drives should be designed with high-fidelity endonucleases and may have implications for other applications that involve genomic integration of CRISPR endonucleases.
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Affiliation(s)
- Anna M Langmüller
- Department of Computational Biology, Cornell UniversityIthacaUnited States
- Institut für Populationsgenetik, Vetmeduni ViennaViennaAustria
- Vienna Graduate School of Population Genetics, Vetmeduni ViennaViennaAustria
| | - Jackson Champer
- Department of Computational Biology, Cornell UniversityIthacaUnited States
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
- Center for Bioinformatics, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking UniversityBeijingChina
| | - Sandra Lapinska
- Department of Computational Biology, Cornell UniversityIthacaUnited States
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Lin Xie
- Department of Computational Biology, Cornell UniversityIthacaUnited States
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Matthew Metzloff
- Department of Computational Biology, Cornell UniversityIthacaUnited States
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Samuel E Champer
- Department of Computational Biology, Cornell UniversityIthacaUnited States
| | - Jingxian Liu
- Department of Computational Biology, Cornell UniversityIthacaUnited States
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Yineng Xu
- Department of Computational Biology, Cornell UniversityIthacaUnited States
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Jie Du
- Center for Bioinformatics, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking UniversityBeijingChina
| | - Andrew G Clark
- Department of Computational Biology, Cornell UniversityIthacaUnited States
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Philipp W Messer
- Department of Computational Biology, Cornell UniversityIthacaUnited States
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29
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Wise IJ, Borry P. An Ethical Overview of the CRISPR-Based Elimination of Anopheles gambiae to Combat Malaria. J Bioeth Inq 2022; 19:371-380. [PMID: 35175513 PMCID: PMC9463432 DOI: 10.1007/s11673-022-10172-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 12/02/2021] [Indexed: 05/07/2023]
Abstract
Approximately a quarter of a billion people around the world suffer from malaria each year. Most cases are located in sub-Saharan Africa where Anopheles gambiae mosquitoes are the principal vectors of this public health problem. With the use of CRISPR-based gene drives, the population of mosquitoes can be modified, eventually causing their extinction. First, we discuss the moral status of the organism and argue that using genetically modified mosquitoes to combat malaria should not be abandoned based on some moral value of A. gambiae. Secondly, we argue that environmental impact studies should be performed to obtain an accurate account of the possible effects of a potential eradication of the organism. However, the risks from the purposeful extinction of A. gambiae should not overtake the benefits of eradicating malaria and risk assessments should be used to determine acceptable risks. Thirdly, we argue that the eventual release of the genetically modified mosquitoes will depend on transparency, community involvement, and cooperation between different nations.
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Affiliation(s)
- India Jane Wise
- Centre for Biomedical Ethics and Law (CBMER), Department of Public Health and Primary Care, Faculty of Medicine, KU Leuven, Kapucijnenvoer 35 Box, 7001 3000 Leuven, Belgium
| | - Pascal Borry
- Centre for Biomedical Ethics and Law (CBMER), Department of Public Health and Primary Care, Faculty of Medicine, KU Leuven, Kapucijnenvoer 35 Box, 7001 3000 Leuven, Belgium
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30
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Khatri BS, Burt A. A theory of resistance to multiplexed gene drive demonstrates the significant role of weakly deleterious natural genetic variation. Proc Natl Acad Sci U S A 2022; 119:e2200567119. [PMID: 35914131 PMCID: PMC9371675 DOI: 10.1073/pnas.2200567119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 06/28/2022] [Indexed: 11/18/2022] Open
Abstract
Evolution of resistance is a major barrier to successful deployment of gene-drive systems to suppress natural populations, which could greatly reduce the burden of many vector-borne diseases. Multiplexed guide RNAs (gRNAs) that require resistance mutations in all target cut sites are a promising antiresistance strategy since, in principle, resistance would only arise in unrealistically large populations. Using stochastic simulations that accurately model evolution at very large population sizes, we explore the probability of resistance due to three important mechanisms: 1) nonhomologous end-joining mutations, 2) single-nucleotide mutants arising de novo, or 3) single-nucleotide polymorphisms preexisting as standing variation. Our results explore the relative importance of these mechanisms and highlight a complexity of the mutation-selection-drift balance between haplotypes with complete resistance and those with an incomplete number of resistant alleles. We find that this leads to a phenomenon where weakly deleterious naturally occurring variants greatly amplify the probability of multisite resistance compared to de novo mutation. This key result provides design criterion for antiresistance multiplexed systems, which, in general, will need a larger number of gRNAs compared to de novo expectations. This theory may have wider application to the evolution of resistance or evolutionary rescue when multiple changes are required before selection can act.
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Affiliation(s)
- Bhavin S. Khatri
- Department of Life Sciences, Imperial College London, Ascot SL5 7PY, United Kingdom
- Chromosome Segregation Laboratory, and Mechanobiology and Biophysics Laboratory, The Francis Crick Institute, London, NW1 1AT, United Kingdom
| | - Austin Burt
- Department of Life Sciences, Imperial College London, Ascot SL5 7PY, United Kingdom
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31
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Gantz VM, Bier E. Active genetics comes alive: Exploring the broad applications of CRISPR-based selfish genetic elements (or gene-drives): Exploring the broad applications of CRISPR-based selfish genetic elements (or gene-drives). Bioessays 2022; 44:e2100279. [PMID: 35686327 PMCID: PMC9397133 DOI: 10.1002/bies.202100279] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 11/11/2022]
Abstract
Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based "active genetic" elements developed in 2015 bypassed the fundamental rules of traditional genetics. Inherited in a super-Mendelian fashion, such selfish genetic entities offered a variety of potential applications including: gene-drives to disseminate gene cassettes carrying desired traits throughout insect populations to control disease vectors or pest species, allelic drives biasing inheritance of preferred allelic variants, neutralizing genetic elements to delete and replace or to halt the spread of gene-drives, split-drives with the core constituent Cas9 endonuclease and guide RNA (gRNA) components inserted at separate genomic locations to accelerate assembly of complex arrays of genetic traits or to gain genetic entry into novel organisms (vertebrates, plants, bacteria), and interhomolog based copying systems in somatic cells to develop tools for treating inherited or infectious diseases. Here, we summarize the substantial advances that have been made on all of these fronts and look forward to the next phase of this rapidly expanding and impactful field.
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Affiliation(s)
- Valentino M Gantz
- Department of Cell and Developmental Biology, University of California, La Jolla, California, USA
| | - Ethan Bier
- Department of Cell and Developmental Biology, University of California, La Jolla, California, USA
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32
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Castle AR, Wohlgemuth S, Arce L, Westaway D. Investigating CRISPR/Cas9 gene drive for production of disease-preventing prion gene alleles. PLoS One 2022; 17:e0269342. [PMID: 35671288 PMCID: PMC9173614 DOI: 10.1371/journal.pone.0269342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 05/18/2022] [Indexed: 11/29/2022] Open
Abstract
Prion diseases are a group of fatal neurodegenerative disorders that includes chronic wasting disease, which affects cervids and is highly transmissible. Given that chronic wasting disease prevalence exceeds 30% in some endemic areas of North America, and that eventual transmission to other mammalian species, potentially including humans, cannot be ruled out, novel control strategies beyond population management via hunting and/or culling must be investigated. Prion diseases depend upon post-translational conversion of the cellular prion protein, encoded by the Prnp gene, into a disease-associated conformation; ablation of cellular prion protein expression, which is generally well-tolerated, eliminates prion disease susceptibility entirely. Inspired by demonstrations of gene drive in caged mosquito species, we aimed to test whether a CRISPR/Cas9-based gene drive mechanism could, in principle, promote the spread of a null Prnp allele among mammalian populations. First, we showed that transient co-expression of Cas9 and Prnp-directed guide RNAs in RK13 cells generates indels within the Prnp open-reading frame, indicating that repair of Cas9-induced double-strand breaks by non-homologous end-joining had taken place. Second, we integrated a ~1.2 kb donor DNA sequence into the Prnp open-reading frame in N2a cells by homology-directed repair following Cas9-induced cleavages and confirmed that integration occurred precisely in most cases. Third, we demonstrated that electroporation of Cas9/guide RNA ribonucleoprotein complexes into fertilised mouse oocytes resulted in pups with a variety of disruptions to the Prnp open reading frame, with a new coisogenic line of Prnp-null mice obtained as part of this work. However, a technical challenge in obtaining expression of Cas9 in the male germline prevented implementation of a complete gene drive mechanism in mice.
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Affiliation(s)
- Andrew R. Castle
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Serene Wohlgemuth
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Luis Arce
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - David Westaway
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
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Bishop AL, López Del Amo V, Okamoto EM, Bodai Z, Komor AC, Gantz VM. Double-tap gene drive uses iterative genome targeting to help overcome resistance alleles. Nat Commun 2022; 13:2595. [PMID: 35534475 PMCID: PMC9085836 DOI: 10.1038/s41467-022-29868-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 02/28/2022] [Indexed: 01/07/2023] Open
Abstract
Homing CRISPR gene drives could aid in curbing the spread of vector-borne diseases and controlling crop pest and invasive species populations due to an inheritance rate that surpasses Mendelian laws. However, this technology suffers from resistance alleles formed when the drive-induced DNA break is repaired by error-prone pathways, which creates mutations that disrupt the gRNA recognition sequence and prevent further gene-drive propagation. Here, we attempt to counteract this by encoding additional gRNAs that target the most commonly generated resistance alleles into the gene drive, allowing a second opportunity at gene-drive conversion. Our presented "double-tap" strategy improved drive efficiency by recycling resistance alleles. The double-tap drive also efficiently spreads in caged populations, outperforming the control drive. Overall, this double-tap strategy can be readily implemented in any CRISPR-based gene drive to improve performance, and similar approaches could benefit other systems suffering from low HDR frequencies, such as mammalian cells or mouse germline transformations.
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Affiliation(s)
- Alena L Bishop
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Víctor López Del Amo
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Emily M Okamoto
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Zsolt Bodai
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Alexis C Komor
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Valentino M Gantz
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA.
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Kokotovich AE, Barnhill-Dilling SK, Elsensohn JE, Li R, Delborne JA, Burrack H. Stakeholder engagement to inform the risk assessment and governance of gene drive technology to manage spotted-wing drosophila. J Environ Manage 2022; 307:114480. [PMID: 35085964 DOI: 10.1016/j.jenvman.2022.114480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 12/31/2021] [Accepted: 01/08/2022] [Indexed: 06/14/2023]
Abstract
Emerging biotechnologies, such as gene drive technology, are increasingly being proposed to manage a variety of pests and invasive species. As one method of genetic biocontrol, gene drive technology is currently being developed to manage the invasive agricultural pest spotted-wing drosophila (Drosophila suzukii, SWD). While there have been calls for stakeholder engagement on gene drive technology, there has been a lack of empirical work, especially concerning stakeholder engagement to inform risk assessment. To help address this gap and inform future risk assessments and governance decisions for SWD gene drive technology, we conducted a survey of 184 SWD stakeholders to explore how they define and prioritize potential benefits and potential adverse effects from proposed SWD gene drive technology. We found that stakeholders considered the most important potential benefits of SWD gene drive technology to be: 1) Decrease in the quantity or toxicity of pesticides used, and 2) Decrease in SWD populations. Stakeholders were most concerned about the potential adverse effects of: 1) Decrease in beneficial insects, 2) Increase in non-SWD secondary pest infestations, and 3) Decrease in grower profits. Notably, we found that even stakeholders who expressed support for the use of SWD gene drive technology expressed concerns about potential adverse effects from the technology, emphasizing the need to move past simplistic, dichotomous views of what it means to support or oppose a technology. These findings suggest that instead of focusing on the binary question of whether stakeholders support or oppose SWD gene drive technology, it is more important to identify and assess the factors that are consequential to stakeholder decision making - including, for example, exploring whether and under what conditions key potential adverse effects and potential benefits would result from the use of SWD gene drive technology.
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Affiliation(s)
- Adam E Kokotovich
- Department of Forestry and Environmental Resources, Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC, USA.
| | - S Kathleen Barnhill-Dilling
- Department of Forestry and Environmental Resources, Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC, USA
| | - Johanna E Elsensohn
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, USA
| | - Richard Li
- Department of Agricultural and Resource Economics, North Carolina State University, Raleigh, NC, USA
| | - Jason A Delborne
- Department of Forestry and Environmental Resources, Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC, USA
| | - Hannah Burrack
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, USA
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35
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Wong JKL, Aichmüller C, Schulze M, Hlevnjak M, Elgaafary S, Lichter P, Zapatka M. Association of mutation signature effectuating processes with mutation hotspots in driver genes and non-coding regions. Nat Commun 2022; 13:178. [PMID: 35013316 PMCID: PMC8748499 DOI: 10.1038/s41467-021-27792-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 12/09/2021] [Indexed: 02/06/2023] Open
Abstract
Cancer driving mutations are difficult to identify especially in the non-coding part of the genome. Here, we present sigDriver, an algorithm dedicated to call driver mutations. Using 3813 whole-genome sequenced tumors from International Cancer Genome Consortium, The Cancer Genome Atlas Program, and a childhood pan-cancer cohort, we employ mutational signatures based on single-base substitution in the context of tri- and penta-nucleotide motifs for hotspot discovery. Knowledge-based annotations on mutational hotspots reveal enrichment in coding regions and regulatory elements for 6 mutational signatures, including APOBEC and somatic hypermutation signatures. APOBEC activity is associated with 32 hotspots of which 11 are known and 11 are putative regulatory drivers. Somatic single nucleotide variants clusters detected at hypermutation-associated hotspots are distinct from translocation or gene amplifications. Patients carrying APOBEC induced PIK3CA driver mutations show lower occurrence of signature SBS39. In summary, sigDriver uncovers mutational processes associated with known and putative tumor drivers and hotspots particularly in the non-coding regions of the genome.
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Affiliation(s)
- John K L Wong
- Division of Molecular Genetics and German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Christian Aichmüller
- Division of Molecular Genetics and German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Markus Schulze
- Computational Oncology Group, Molecular Precision Oncology Program, National Center for Tumor Diseases (NCT) and DKFZ, Heidelberg, Germany
| | - Mario Hlevnjak
- Computational Oncology Group, Molecular Precision Oncology Program, National Center for Tumor Diseases (NCT) and DKFZ, Heidelberg, Germany
| | - Shaymaa Elgaafary
- Gynecologic Oncology, National Center for Tumor Diseases (NCT) and University of Heidelberg, Heidelberg, Germany
- Molecular Precision Oncology Program at the National Center for Tumor Diseases (NCT) and DKFZ, Heidelberg, Germany
| | - Peter Lichter
- Division of Molecular Genetics and German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Molecular Precision Oncology Program at the National Center for Tumor Diseases (NCT) and DKFZ, Heidelberg, Germany
| | - Marc Zapatka
- Division of Molecular Genetics and German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany.
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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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Abstract
This paper is concerned with a reaction-diffusion system modeling the fixation and the invasion in a population of a gene drive (an allele biasing inheritance, increasing its own transmission to offspring). In our model, the gene drive has a negative effect on the fitness of individuals carrying it, and is therefore susceptible of decreasing the total carrying capacity of the population locally in space. This tends to generate an opposing demographic advection that the gene drive has to overcome in order to invade. While previous reaction-diffusion models neglected this aspect, here we focus on it and try to predict the sign of the traveling wave speed. It turns out to be an analytical challenge, only partial results being within reach, and we complete our theoretical analysis by numerical simulations. Our results indicate that taking into account the interplay between population dynamics and population genetics might actually be crucial, as it can effectively reverse the direction of the invasion and lead to failure. Our findings can be extended to other bistable systems, such as the spread of cytoplasmic incompatibilities caused by Wolbachia.
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Affiliation(s)
- Léo Girardin
- CNRS, Institut Camille Jordan, Université Claude Bernard Lyon-1, 43 Boulevard du 11 Novembre 1918, 69622, Villeurbanne Cedex, France.
| | - Florence Débarre
- CNRS, Sorbonne Université, Université Paris Est Creteil, INRAE, IRD, Institute of Ecology and Environmental Sciences, Paris, IEES-Paris, 4 Place Jussieu, 75005, Paris, France
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38
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Siddiqui HA, Harvey-Samuel T, Mansoor S. Gene drive: a faster route to plant improvement. Trends Plant Sci 2021; 26:1204-1206. [PMID: 34625344 DOI: 10.1016/j.tplants.2021.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/16/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
Gene drives for control of vector-borne diseases have been demonstrated in insects but remain challenging in plants. Theoretically, they could be transformative in speeding breeding programs and contributing to food security through providing novel weed control methods. Zhang et al. now report the possibility of implementing gene drive in plants for the first time.
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Affiliation(s)
- Hamid Anees Siddiqui
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, a constituent College of Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | | | - Shahid Mansoor
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, a constituent College of Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan.
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39
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James S, O’Brochta D. New Arthropod Containment Recommendations Provide Essential Guidance for Safety of Gene Drive Research. Am J Trop Med Hyg 2021; 106:1-2. [PMID: 34847531 PMCID: PMC8733505 DOI: 10.4269/ajtmh.21-1148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 11/01/2021] [Indexed: 11/09/2022] Open
Affiliation(s)
- Stephanie James
- Address correspondence to Stephanie James, Foundation for the National Institutes of Health, 11400 Rockville Pike, Suite 600, North Bethesda, MD 20852. E-mail:
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40
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Reid WR, Olson KE, Franz AWE. Current Effector and Gene-Drive Developments to Engineer Arbovirus-Resistant Aedes aegypti (Diptera: Culicidae) for a Sustainable Population Replacement Strategy in the Field. J Med Entomol 2021; 58:1987-1996. [PMID: 33704462 PMCID: PMC8421695 DOI: 10.1093/jme/tjab030] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Indexed: 05/13/2023]
Abstract
Arthropod-borne viruses (arboviruses) such as dengue, Zika, and chikungunya viruses cause morbidity and mortality among human populations living in the tropical regions of the world. Conventional mosquito control efforts based on insecticide treatments and/or the use of bednets and window curtains are currently insufficient to reduce arbovirus prevalence in affected regions. Novel, genetic strategies that are being developed involve the genetic manipulation of mosquitoes for population reduction and population replacement purposes. Population replacement aims at replacing arbovirus-susceptible wild-type mosquitoes in a target region with those that carry a laboratory-engineered antiviral effector to interrupt arboviral transmission in the field. The strategy has been primarily developed for Aedes aegypti (L.), the most important urban arbovirus vector. Antiviral effectors based on long dsRNAs, miRNAs, or ribozymes destroy viral RNA genomes and need to be linked to a robust gene drive to ensure their fixation in the target population. Synthetic gene-drive concepts are based on toxin/antidote, genetic incompatibility, and selfish genetic element principles. The CRISPR/Cas9 gene editing system can be configurated as a homing endonuclease gene (HEG) and HEG-based drives became the preferred choice for mosquitoes. HEGs are highly allele and nucleotide sequence-specific and therefore sensitive to single-nucleotide polymorphisms/resistant allele formation. Current research efforts test new HEG-based gene-drive designs that promise to be less sensitive to resistant allele formation. Safety aspects in conjunction with gene drives are being addressed by developing procedures that would allow a recall or overwriting of gene-drive transgenes once they have been released.
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Affiliation(s)
- William R Reid
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, USA
| | - Ken E Olson
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Alexander W E Franz
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, USA
- Corresponding author, e-mail:
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Abstract
In response to growing concerns regarding mosquito-borne diseases, scientists are developing novel systems of vector control. Early examples include Oxitec's OX513A genetically-engineered mosquito and MosquitoMate's Wolbachia-infected mosquito, and systems using 'gene-drive' are in development. Systems based on genetic engineering are controversial and institutions around the world are grappling with the question of who should have a say in how such technologies are field-tested and used. Based on media coverage and public records, we created comparative timelines of the efforts of Oxitec and MosquitoMate to navigate federal and local governance and bring their products to market in the United States. We analyze these timelines with particular attention to the role of public input in technology governance. These cases illustrate how governance of technology in the US is diverse, complex, and opaque. Further, the public response to proposed field trials of the Oxitec product highlights inconsistencies between public expectations for governance and actual practice. As gene-drive mosquito control products develop, both federal and local agencies will find their legitimacy tested without a better procedure for transparently integrating public input.
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Affiliation(s)
- Cynthia E. Schairer
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - James Najera
- Department of Biology, University of California, San Diego, La Jolla, CA, USA
| | - Anthony A. James
- Departments of Microbiology & Molecular Genetics and Molecular Biology & Biochemistry, University of California, Irvine, CA, USA
| | - Omar S. Akbari
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, USA
- Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, USA
| | - Cinnamon S. Bloss
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
- Department of Family Medicine and Public Health, School of Medicine, University of California, San Diego, La Jolla, CA, USA
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Wu SL, Bennett JB, Sánchez C. HM, Dolgert AJ, León TM, Marshall JM. MGDrivE 2: A simulation framework for gene drive systems incorporating seasonality and epidemiological dynamics. PLoS Comput Biol 2021; 17:e1009030. [PMID: 34019537 PMCID: PMC8186770 DOI: 10.1371/journal.pcbi.1009030] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 06/08/2021] [Accepted: 05/02/2021] [Indexed: 12/30/2022] Open
Abstract
Interest in gene drive technology has continued to grow as promising new drive systems have been developed in the lab and discussions are moving towards implementing field trials. The prospect of field trials requires models that incorporate a significant degree of ecological detail, including parameters that change over time in response to environmental data such as temperature and rainfall, leading to seasonal patterns in mosquito population density. Epidemiological outcomes are also of growing importance, as: i) the suitability of a gene drive construct for release will depend on its expected impact on disease transmission, and ii) initial field trials are expected to have a measured entomological outcome and a modeled epidemiological outcome. We present MGDrivE 2 (Mosquito Gene Drive Explorer 2): a significant development from the MGDrivE 1 simulation framework that investigates the population dynamics of a variety of gene drive architectures and their spread through spatially-explicit mosquito populations. Key strengths and fundamental improvements of the MGDrivE 2 framework are: i) the ability of parameters to vary with time and induce seasonal population dynamics, ii) an epidemiological module accommodating reciprocal pathogen transmission between humans and mosquitoes, and iii) an implementation framework based on stochastic Petri nets that enables efficient model formulation and flexible implementation. Example MGDrivE 2 simulations are presented to demonstrate the application of the framework to a CRISPR-based split gene drive system intended to drive a disease-refractory gene into a population in a confinable and reversible manner, incorporating time-varying temperature and rainfall data. The simulations also evaluate impact on human disease incidence and prevalence. Further documentation and use examples are provided in vignettes at the project’s CRAN repository. MGDrivE 2 is freely available as an open-source R package on CRAN (https://CRAN.R-project.org/package=MGDrivE2). We intend the package to provide a flexible tool capable of modeling gene drive constructs as they move closer to field application and to infer their expected impact on disease transmission. Malaria, dengue and other mosquito-borne diseases continue to pose a major global health burden through much of the world. Currently available tools, such as insecticides and antimalarial drugs, are not expected to be sufficient to eliminate these diseases from highly-endemic areas, hence there is interest in novel strategies including genetics-based approaches. In recent years, the advent of CRISPR-based gene-editing has greatly expanded the range of genetic control tools available, and MGDrivE 1 (Mosquito Gene Drive Explorer 1) was proposed to simulate the dynamics of these systems through spatially-structured mosquito populations. As the technology has advanced and potential field trials are being discussed, models are now needed that incorporate additional details, such as life history parameters that respond to daily and seasonal environmental fluctuations, and transmission of pathogens between mosquito and vertebrate hosts. Here, we present MGDrivE 2, a gene drive simulation framework that significantly improves upon MGDrivE 1 by addressing these modeling needs. MGDrivE 2 has also been reformulated as a stochastic Petri net, enabling model specification to be decoupled from simulation, making it easier to adapt the model for application to other insect and mammalian species.
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Affiliation(s)
- Sean L. Wu
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
- * E-mail: (SLW); (JMM)
| | - Jared B. Bennett
- Biophysics Graduate Group, Division of Biological Sciences, College of Letters and Science, University of California, Berkeley, California, United States of America
| | - Héctor M. Sánchez C.
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - Andrew J. Dolgert
- Institute for Health Metrics and Evaluation, Seattle, Washington, United States of America
| | - Tomás M. León
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - John M. Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
- Innovative Genomics Institute, University of California, Berkeley, California, United States of America
- * E-mail: (SLW); (JMM)
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43
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Hartley S, Ledingham K, Owen R, Leonelli S, Diarra S, Diop S. Experimenting with co-development: A qualitative study of gene drive research for malaria control in Mali. Soc Sci Med 2021; 276:113850. [PMID: 33839526 DOI: 10.1016/j.socscimed.2021.113850] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/12/2021] [Accepted: 03/13/2021] [Indexed: 11/17/2022]
Abstract
We investigate how technology 'co-development' (between researchers, stakeholders and local communities) is framed in practice by those developing gene drive mosquitos for malaria eradication. Our case study focuses on UK and Mali-based researchers planning to undertake the first field trials in Mali of gene drive mosquitos for malaria control. While they and the wider gene drive research community are explicitly committed to the principle of co-development, how this is framed and practiced is not clear. Through qualitative analysis of 34 interviews complemented by observation and documentary research conducted in 2018, we identify and compare ten framings of co-development mobilised by UK and Malian researchers and stakeholders. For Malians, co-development reflected Mali's broader socio-political context and a desire for African scientific independence and leadership. It was mobilised to secure community and stakeholder support for gene drive mosquito field trials, through outreach, building local scientific capacity and developing those institutions (e.g. regulatory) necessary for field trials to go ahead. For UK participants, co-development was also concerned with scientific capacity-building, knowledge exchange between researchers, and stakeholder and community outreach to secure consent for field trials. Overall, our findings suggest co-development is opening up previously expert-dominated spaces as researchers attempt to take responsibility for the societal implications of their work. However, its main function is as a project management tool to enable and instrumentally support technological development, field trials and eventual deployment. This function extends into areas which are traditionally the responsibility of the state, such as regulatory development, facilitated by Mali's fragile political and economic situation. Paradoxically, co-development simultaneously depoliticises gene drive, masking power relations and closing down substantive debate and agency. Characterised by extreme poverty, conflict and weak institutions, Mali may become a site for technological experimentation where there is little interrogation of gene drive or its governance.
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Affiliation(s)
- Sarah Hartley
- Department of Science, Innovation, Technology and Entrepreneurship, University of Exeter, UK.
| | - Katie Ledingham
- Department of Science, Innovation, Technology and Entrepreneurship, University of Exeter, UK
| | - Richard Owen
- School of Economics, Finance and Management, University of Bristol, UK
| | - Sabina Leonelli
- Department of Sociology, Philosophy and Anthropology, University of Exeter, UK
| | - Samba Diarra
- Faculty of Medicine, University of Sciences, Techniques and Technologies of Bamako, Mali
| | - Samba Diop
- Faculty of Medicine, University of Sciences, Techniques and Technologies of Bamako, Mali
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44
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Connolly JB, Mumford JD, Fuchs S, Turner G, Beech C, North AR, Burt A. Systematic identification of plausible pathways to potential harm via problem formulation for investigational releases of a population suppression gene drive to control the human malaria vector Anopheles gambiae in West Africa. Malar J 2021; 20:170. [PMID: 33781254 PMCID: PMC8006393 DOI: 10.1186/s12936-021-03674-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Population suppression gene drive has been proposed as a strategy for malaria vector control. A CRISPR-Cas9-based transgene homing at the doublesex locus (dsxFCRISPRh) has recently been shown to increase rapidly in frequency in, and suppress, caged laboratory populations of the malaria mosquito vector Anopheles gambiae. Here, problem formulation, an initial step in environmental risk assessment (ERA), was performed for simulated field releases of the dsxFCRISPRh transgene in West Africa. METHODS Building on consultative workshops in Africa that previously identified relevant environmental and health protection goals for ERA of gene drive in malaria vector control, 8 potentially harmful effects from these simulated releases were identified. These were stratified into 46 plausible pathways describing the causal chain of events that would be required for potential harms to occur. Risk hypotheses to interrogate critical steps in each pathway, and an analysis plan involving experiments, modelling and literature review to test each of those risk hypotheses, were developed. RESULTS Most potential harms involved increased human (n = 13) or animal (n = 13) disease transmission, emphasizing the importance to subsequent stages of ERA of data on vectorial capacity comparing transgenics to non-transgenics. Although some of the pathways (n = 14) were based on known anatomical alterations in dsxFCRISPRh homozygotes, many could also be applicable to field releases of a range of other transgenic strains of mosquito (n = 18). In addition to population suppression of target organisms being an accepted outcome for existing vector control programmes, these investigations also revealed that the efficacy of population suppression caused by the dsxFCRISPRh transgene should itself directly affect most pathways (n = 35). CONCLUSIONS Modelling will play an essential role in subsequent stages of ERA by clarifying the dynamics of this relationship between population suppression and reduction in exposure to specific potential harms. This analysis represents a comprehensive identification of plausible pathways to potential harm using problem formulation for a specific gene drive transgene and organism, and a transparent communication tool that could inform future regulatory studies, guide subsequent stages of ERA, and stimulate further, broader engagement on the use of population suppression gene drive to control malaria vectors in West Africa.
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Affiliation(s)
- John B Connolly
- Department of Life Sciences, Imperial College London, London, UK.
| | - John D Mumford
- Centre for Environmental Policy, Imperial College London, London, UK
| | - Silke Fuchs
- Department of Life Sciences, Imperial College London, London, UK
| | - Geoff Turner
- Department of Life Sciences, Imperial College London, London, UK
| | | | - Ace R North
- Department of Zoology, University of Oxford, Oxford, UK
| | - Austin Burt
- Department of Life Sciences, Imperial College London, London, UK
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Abstract
Gene drives are selfish genetic elements that can be re-designed to invade a population and they hold tremendous potential for the control of mosquitoes that transmit disease. Much progress has been made recently in demonstrating proof of principle for gene drives able to suppress populations of malarial mosquitoes, or to make them refractory to the Plasmodium parasites they transmit. This has been achieved using CRISPR-based gene drives. In this article, I will discuss the relative merits of this type of gene drive, as well as barriers to its technical development and to its deployment in the field as malaria control. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.
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Affiliation(s)
- Tony Nolan
- Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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Abstract
Insects play important roles as predators, prey, pollinators, recyclers, hosts, parasitoids, and sources of economically important products. They can also destroy crops; wound animals; and serve as vectors for plant, animal, and human diseases. Gene drive-a process by which genes, gene complexes, or chromosomes encoding specific traits are made to spread through wild populations, even if these traits result in a fitness cost to carriers-provides new opportunities for altering populations to benefit humanity and the environment in ways that are species specific and sustainable. Gene drive can be used to alter the genetic composition of an existing population, referred to as population modification or replacement, or to bring about population suppression or elimination. We describe technologies under consideration, progress that has been made, and remaining technological hurdles, particularly with respect to evolutionary stability and our ability to control the spread and ultimate fate of genes introduced into populations.
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Affiliation(s)
- Bruce A Hay
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA; ,
- St. John's College, University of Cambridge, Cambridge CB2 1TP, United Kingdom
| | - Georg Oberhofer
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA; ,
| | - Ming Guo
- Departments of Neurology and Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA;
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Devos Y, Bonsall MB, Firbank LG, Mumford J, Nogué F, Wimmer EA. Gene Drive-Modified Organisms: Developing Practical Risk Assessment Guidance. Trends Biotechnol 2020; 39:853-856. [PMID: 33342557 DOI: 10.1016/j.tibtech.2020.11.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 12/23/2022]
Abstract
Risk assessors, risk managers, developers, potential applicants, and other stakeholders at many levels discuss the need for new or further risk assessment guidance for deliberate environmental releases of gene drive-modified organisms. However, preparing useful and practical guidance entails challenges, to which we offer recommendations based on our experience drafting guidance.
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Affiliation(s)
- Yann Devos
- GMO Unit, European Food Safety Authority (EFSA), Parma, Italy.
| | | | | | - John Mumford
- Centre for Environmental Policy, Imperial College London, Ascot, UK
| | - Fabien Nogué
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Ernst A Wimmer
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, GZMB, Georg August University, Göttingen, Germany
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48
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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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49
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Schairer CE, Triplett C, Buchman A, Akbari OS, Bloss CS. Interdisciplinary development of a standardized introduction to gene drives for lay audiences. BMC Med Res Methodol 2020; 20:273. [PMID: 33153449 PMCID: PMC7643426 DOI: 10.1186/s12874-020-01146-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 10/12/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND While there is wide consensus that the public should be consulted about emerging technology early in development, it is difficult to elicit public opinion about innovations unfamiliar to lay audiences. We sought public input on a program of research on genetic engineering to control mosquito vectors of disease that is led by scientists at the University of California and funded by the U.S. Defense Advanced Research Projects Agency (DARPA). In preparation for this effort, we developed a series of narrated slideshows to prompt responses to the development of gene drive mosquito control strategies among lay people. We describe the development and content of these slideshows and evaluate their ability to elicit discussions among focus group participants. METHODS In developing these materials, we used an iterative process involving input from experts in molecular genetics and vector control. Topics were chosen for their relevance to the goals of the scientists leading the program of research. Significant time was devoted to crafting explanations that would be accessible to uninitiated members of the public but still represent the science accurately. Through qualitative analysis of focus group discussions prompted by the slideshows, we evaluated the success of these slideshows in imparting clear technical information sufficient to inform lay discussion. RESULTS The collaboration resulted in a series of four narrated slideshows that were used to anchor discussions in online focus groups. Many participants described the slideshows as interesting and informative, while also raising concerns and possible risks that were not directly addressed in the material presented. Open-ended comments from participants suggest that the slideshows inspired critical questions, reflection, and conversation about genetically engineered and gene drive mosquitoes. After the final and most technically complex slideshow, however, some respondents made comments suggestive of overwhelm or confusion. CONCLUSION Our narrated slideshows prompted engaged conversations about genetically engineered mosquitoes among members of the public who were generally naïve to this technology. Narrated slideshows may serve as viable and useful tools for future public engagement on other controversial emerging medical and public health technologies.
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Affiliation(s)
- Cynthia E Schairer
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, MC 0811, La Jolla, California, 92093-0811, USA
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, USA
| | - Cynthia Triplett
- Center for Wireless and Population Health Systems, The Qualcomm Institute of Calit2, University of California, San Diego, La Jolla, CA, USA
| | - Anna Buchman
- Section of Cell and Developmental Biology, Division of Biology, University of California, San Diego, La Jolla, CA, USA
| | - Omar S Akbari
- Section of Cell and Developmental Biology, Division of Biology, University of California, San Diego, La Jolla, CA, USA
- Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, USA
| | - Cinnamon S Bloss
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, MC 0811, La Jolla, California, 92093-0811, USA.
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, USA.
- Center for Wireless and Population Health Systems, The Qualcomm Institute of Calit2, University of California, San Diego, La Jolla, CA, USA.
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50
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Gardiner DM, Rusu A, Barrett L, Hunter GC, Kazan K. Can natural gene drives be part of future fungal pathogen control strategies in plants? New Phytol 2020; 228:1431-1439. [PMID: 32593207 DOI: 10.1111/nph.16779] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 06/15/2020] [Indexed: 06/11/2023]
Abstract
Globally, fungal pathogens cause enormous crop losses and current control practices are not always effective, economical or environmentally sustainable. Tools enabling genetic management of wild pathogen populations could potentially solve many problems associated with plant diseases. A natural gene drive from a heterologous species can be used in the globally important cereal pathogen Fusarium graminearum to remove pathogenic traits from contained populations of the fungus. The gene drive element became fixed in a freely crossing population in only three generations. Repeat-induced point mutation (RIP), a natural genome defence mechanism in fungi that causes C to T mutations during meiosis in highly similar sequences, may be useful to recall the gene drive following release, should a failsafe mechanism be required. We propose that gene drive technology is a potential tool to control plant pathogens once its efficacy is demonstrated under natural settings.
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Affiliation(s)
- Donald M Gardiner
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation (CSIRO), 306 Carmody Road, St Lucia, Queensland, 4067, Australia
| | - Anca Rusu
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation (CSIRO), 306 Carmody Road, St Lucia, Queensland, 4067, Australia
| | - Luke Barrett
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clunies Ross Street, Acton, ACT, 2601, Australia
| | - Gavin C Hunter
- Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clunies Ross Street, Acton, ACT, 2601, Australia
| | - Kemal Kazan
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation (CSIRO), 306 Carmody Road, St Lucia, Queensland, 4067, Australia
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