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Wudarski J, Aliabadi S, Gulia-Nuss M. Arthropod promoters for genetic control of disease vectors. Trends Parasitol 2024; 40:619-632. [PMID: 38824066 PMCID: PMC11223965 DOI: 10.1016/j.pt.2024.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/15/2024] [Accepted: 04/15/2024] [Indexed: 06/03/2024]
Abstract
Vector-borne diseases (VBDs) impose devastating effects on human health and a heavy financial burden. Malaria, Lyme disease, and dengue fever are just a few examples of VBDs that cause severe illnesses. The current strategies to control VBDs consist mainly of environmental modification and chemical use, and to a small extent, genetic approaches. The genetic approaches, including transgenesis/genome modification and gene-drive technologies, provide the basis for developing new tools for VBD prevention by suppressing vector populations or reducing their capacity to transmit pathogens. The regulatory elements such as promoters are required for a robust sex-, tissue-, and stage-specific transgene expression. As discussed in this review, information on the regulatory elements is available for mosquito vectors but is scant for other vectors.
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Affiliation(s)
- Jakub Wudarski
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, USA
| | - Simindokht Aliabadi
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, USA
| | - Monika Gulia-Nuss
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, USA.
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2
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Kefi M, Cardoso-Jaime V, Saab SA, Dimopoulos G. Curing mosquitoes with genetic approaches for malaria control. Trends Parasitol 2024; 40:487-499. [PMID: 38760256 DOI: 10.1016/j.pt.2024.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/15/2024] [Accepted: 04/15/2024] [Indexed: 05/19/2024]
Abstract
Malaria remains a persistent global public health challenge because of the limitations of current prevention tools. The use of transgenic mosquitoes incapable of transmitting malaria, in conjunction with existing methods, holds promise for achieving elimination of malaria and preventing its reintroduction. In this context, population modification involves the spread of engineered genetic elements through mosquito populations that render them incapable of malaria transmission. Significant progress has been made in this field over the past decade in revealing promising targets, optimizing genetic tools, and facilitating the transition from the laboratory to successful field deployments, which are subject to regulatory scrutiny. This review summarizes recent advances and ongoing challenges in 'curing' Anopheles vectors of the malaria parasite.
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Affiliation(s)
- Mary Kefi
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Victor Cardoso-Jaime
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Sally A Saab
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - George Dimopoulos
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
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3
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Du J, Chen W, Jia X, Xu X, Yang E, Zhou R, Zhang Y, Metzloff M, Messer PW, Champer J. Germline Cas9 promoters with improved performance for homing gene drive. Nat Commun 2024; 15:4560. [PMID: 38811556 PMCID: PMC11137117 DOI: 10.1038/s41467-024-48874-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 05/16/2024] [Indexed: 05/31/2024] Open
Abstract
Gene drive systems could be a viable strategy to prevent pathogen transmission or suppress vector populations by propagating drive alleles with super-Mendelian inheritance. CRISPR-based homing gene drives convert wild type alleles into drive alleles in heterozygotes with Cas9 and gRNA. It is thus desirable to identify Cas9 promoters that yield high drive conversion rates, minimize the formation rate of resistance alleles in both the germline and the early embryo, and limit somatic Cas9 expression. In Drosophila, the nanos promoter avoids leaky somatic expression, but at the cost of high embryo resistance from maternally deposited Cas9. To improve drive efficiency, we test eleven Drosophila melanogaster germline promoters. Some achieve higher drive conversion efficiency with minimal embryo resistance, but none completely avoid somatic expression. However, such somatic expression often does not carry detectable fitness costs for a rescue homing drive targeting a haplolethal gene, suggesting somatic drive conversion. Supporting a 4-gRNA suppression drive, one promoter leads to a low drive equilibrium frequency due to fitness costs from somatic expression, but the other outperforms nanos, resulting in successful suppression of the cage population. Overall, these Cas9 promoters hold advantages for homing drives in Drosophila species and may possess valuable homologs in other organisms.
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Affiliation(s)
- Jie Du
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, 100871, Beijing, China.
| | - Weizhe Chen
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, 100871, Beijing, China
- School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Xihua Jia
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, 100871, Beijing, China
| | - Xuejiao Xu
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, 100871, Beijing, China
| | - Emily Yang
- Department of Computational Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Ruizhi Zhou
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, 100871, Beijing, China
| | - Yuqi Zhang
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, 100871, Beijing, China
| | - Matt Metzloff
- Department of Computational Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Philipp W Messer
- Department of Computational Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Jackson Champer
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, 100871, Beijing, China.
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4
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Chae K, Contreras B, Romanowski JS, Dawson C, Myles KM, Adelman ZN. Transgene removal using an in cis programmed homing endonuclease via single-strand annealing in the mosquito Aedes aegypti. Commun Biol 2024; 7:660. [PMID: 38811748 PMCID: PMC11137009 DOI: 10.1038/s42003-024-06348-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 05/17/2024] [Indexed: 05/31/2024] Open
Abstract
While gene drive strategies have been proposed to aid in the control of mosquito-borne diseases, additional genome engineering technologies may be required to establish a defined end-of-product-life timeline. We previously demonstrated that single-strand annealing (SSA) was sufficient to program the scarless elimination of a transgene while restoring a disrupted gene in the disease vector mosquito Aedes aegypti. Here, we extend these findings by establishing that complete transgene removal (four gene cassettes comprising ~8-kb) can be programmed in cis. Reducing the length of the direct repeat from 700-bp to 200-bp reduces, but does not eliminate, SSA activity. In contrast, increasing direct repeat length to 1.5-kb does not increase SSA rates, suggesting diminishing returns above a certain threshold size. Finally, we show that while the homing endonuclease Y2-I-AniI triggered both SSA and NHEJ at significantly higher rates than I-SceI at one genomic locus (P5-EGFP), repair events are heavily skewed towards NHEJ at another locus (kmo), suggesting the nuclease used and the genomic region targeted have a substantial influence on repair outcomes. Taken together, this work establishes the feasibility of engineering temporary transgenes in disease vector mosquitoes, while providing critical details concerning important operational parameters.
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Affiliation(s)
- Keun Chae
- Department of Entomology, Texas A&M University, College Station, TX, 77843, USA
| | - Bryan Contreras
- Department of Entomology, Texas A&M University, College Station, TX, 77843, USA
| | - Joseph S Romanowski
- Department of Entomology, Texas A&M University, College Station, TX, 77843, USA
| | - Chanell Dawson
- Department of Entomology, Texas A&M University, College Station, TX, 77843, USA
| | - Kevin M Myles
- Department of Entomology, Texas A&M University, College Station, TX, 77843, USA
| | - Zach N Adelman
- Department of Entomology, Texas A&M University, College Station, TX, 77843, USA.
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5
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Ambrose L, Allen SL, Iro'ofa C, Butafa C, Beebe NW. Genetic and geographic population structure in the malaria vector, Anopheles farauti, provides a candidate system for pioneering confinable gene-drive releases. Heredity (Edinb) 2024; 132:232-246. [PMID: 38494530 DOI: 10.1038/s41437-024-00677-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 02/27/2024] [Accepted: 02/29/2024] [Indexed: 03/19/2024] Open
Abstract
Indoor insecticide applications are the primary tool for reducing malaria transmission in the Solomon Archipelago, a region where Anopheles farauti is the only common malaria vector. Due to the evolution of behavioural resistance in some An. farauti populations, these applications have become less effective. New malaria control interventions are therefore needed in this region, and gene-drives provide a promising new technology. In considering developing a population-specific (local) gene-drive in An. farauti, we detail the species' population genetic structure using microsatellites and whole mitogenomes, finding many spatially confined populations both within and between landmasses. This strong population structure suggests that An. farauti would be a useful system for developing a population-specific, confinable gene-drive for field release, where private alleles can be used as Cas9 targets. Previous work on Anopheles gambiae has used the Cardinal gene for the development of a global population replacement gene-drive. We therefore also analyse the Cardinal gene to assess whether it may be a suitable target to engineer a gene-drive for the modification of local An. farauti populations. Despite the extensive population structure observed in An. farauti for microsatellites, only one remote island population from Vanuatu contained fixed and private alleles at the Cardinal locus. Nonetheless, this study provides an initial framework for further population genomic investigations to discover high-frequency private allele targets in localized An. farauti populations. This would enable the development of gene-drive strains for modifying localised populations with minimal chance of escape and may provide a low-risk route to field trial evaluations.
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Affiliation(s)
- Luke Ambrose
- School of the Environment, University of Queensland, St Lucia, Brisbane, QLD, Australia.
| | - Scott L Allen
- School of the Environment, University of Queensland, St Lucia, Brisbane, QLD, Australia
| | - Charlie Iro'ofa
- Solomon Islands Ministry of Health, Honiara, Guadalcanal, Solomon Islands
| | - Charles Butafa
- Solomon Islands Ministry of Health, Honiara, Guadalcanal, Solomon Islands
| | - Nigel W Beebe
- School of the Environment, University of Queensland, St Lucia, Brisbane, QLD, Australia.
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6
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Sánchez C. HM, Smith DL, Marshall JM. MGSurvE: A framework to optimize trap placement for genetic surveillance of mosquito populations. PLoS Comput Biol 2024; 20:e1012046. [PMID: 38709820 PMCID: PMC11098508 DOI: 10.1371/journal.pcbi.1012046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 05/16/2024] [Accepted: 04/02/2024] [Indexed: 05/08/2024] Open
Abstract
Genetic surveillance of mosquito populations is becoming increasingly relevant as genetics-based mosquito control strategies advance from laboratory to field testing. Especially applicable are mosquito gene drive projects, the potential scale of which leads monitoring to be a significant cost driver. For these projects, monitoring will be required to detect unintended spread of gene drive mosquitoes beyond field sites, and the emergence of alternative alleles, such as drive-resistant alleles or non-functional effector genes, within intervention sites. This entails the need to distribute mosquito traps efficiently such that an allele of interest is detected as quickly as possible-ideally when remediation is still viable. Additionally, insecticide-based tools such as bednets are compromised by insecticide-resistance alleles for which there is also a need to detect as quickly as possible. To this end, we present MGSurvE (Mosquito Gene SurveillancE): a computational framework that optimizes trap placement for genetic surveillance of mosquito populations such that the time to detection of an allele of interest is minimized. A key strength of MGSurvE is that it allows important biological features of mosquitoes and the landscapes they inhabit to be accounted for, namely: i) resources required by mosquitoes (e.g., food sources and aquatic breeding sites) can be explicitly distributed through a landscape, ii) movement of mosquitoes may depend on their sex, the current state of their gonotrophic cycle (if female) and resource attractiveness, and iii) traps may differ in their attractiveness profile. Example MGSurvE analyses are presented to demonstrate optimal trap placement for: i) an Aedes aegypti population in a suburban landscape in Queensland, Australia, and ii) an Anopheles gambiae population on the island of São Tomé, São Tomé and Príncipe. Further documentation and use examples are provided in project's documentation. MGSurvE is intended as a resource for both field and computational researchers interested in mosquito gene surveillance.
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Affiliation(s)
- Héctor M. Sánchez C.
- Divisions of Epidemiology and Biostatistics, University of California Berkeley, Berkeley, California, United States of America
| | - David L. Smith
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington, United States of America
- Department of Health Metrics Sciences, School of Medicine, University of Washington, Seattle, Washington, United States of America
| | - John M. Marshall
- Divisions of Epidemiology and Biostatistics, University of California Berkeley, Berkeley, California, United States of America
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7
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Erriah B, Shtukenberg AG, Aronin R, McCarthy D, Brázda P, Ward MD, Kahr B. ROY Crystallization on Poly(ethylene) Fibers, a Model for Bed Net Crystallography. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2024; 36:2432-2440. [PMID: 38495899 PMCID: PMC10938503 DOI: 10.1021/acs.chemmater.3c03188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/13/2024] [Accepted: 02/14/2024] [Indexed: 03/19/2024]
Abstract
Many long-lasting insecticidal bed nets for protection against disease vectors consist of poly(ethylene) fibers in which insecticide is incorporated during manufacture. Insecticide molecules diffuse from within the supersaturated polymers to surfaces where they become bioavailable to insects and often crystallize, a process known as blooming. Recent studies revealed that contact insecticides can be highly polymorphic. Moreover, insecticidal activity is polymorph-dependent, with forms having a higher crystal free energy yielding faster insect knockdown and mortality. Consequently, the crystallographic characterization of insecticide crystals that form on fibers is critical to understanding net function and improving net performance. Structural characterization of insecticide crystals on bed net fiber surfaces, let alone their polymorphs, has been elusive owing to the minute size of the crystals, however. Using the highly polymorphous compound ROY (5-methyl-2-[(2-nitrophenyl)-amino]thiophene-3-carbonitrile) as a proxy for insecticide crystallization, we investigated blooming and crystal formation on the surface of extruded poly(ethylene) fibers containing ROY. The blooming rates, tracked from the time of extrusion, were determined by UV-vis spectroscopy after successive washes. Six crystalline polymorphs (of the 13 known) were observed on poly(ethylene) fiber surfaces, and they were identified and characterized by Raman microscopy, scanning electron microscopy, and 3D electron diffraction. These observations reveal that the crystallization and phase behavior of polymorphs forming on poly(ethylene) fibers is complex and dynamic. The characterization of blooming and microcrystals underscores the importance of bed net crystallography for the optimization of bed net performance.
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Affiliation(s)
- Bryan Erriah
- Department
of Chemistry and Molecular Design Institute, New York University, New York, 29 Washington Place, New York City, New York 10003, United States
| | - Alexander G. Shtukenberg
- Department
of Chemistry and Molecular Design Institute, New York University, New York, 29 Washington Place, New York City, New York 10003, United States
| | - Reese Aronin
- Department
of Chemistry and Molecular Design Institute, New York University, New York, 29 Washington Place, New York City, New York 10003, United States
| | - Derik McCarthy
- Department
of Chemistry and Molecular Design Institute, New York University, New York, 29 Washington Place, New York City, New York 10003, United States
| | - Petr Brázda
- Department
of Structure Analysis, Institute of Physics, Czech Academy of Sciences, Na Slovance 2/1999, Prague 8 18221, Czech Republic
| | - Michael D. Ward
- Department
of Chemistry and Molecular Design Institute, New York University, New York, 29 Washington Place, New York City, New York 10003, United States
| | - Bart Kahr
- Department
of Chemistry and Molecular Design Institute, New York University, New York, 29 Washington Place, New York City, New York 10003, United States
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8
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Coutinho-Abreu IV, Jamshidi O, Raban R, Atabakhsh K, Merriman JA, Akbari OS. Identification of human skin microbiome odorants that manipulate mosquito landing behavior. Sci Rep 2024; 14:1631. [PMID: 38238397 PMCID: PMC10796395 DOI: 10.1038/s41598-023-50182-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 12/16/2023] [Indexed: 01/22/2024] Open
Abstract
The resident human skin microbiome is responsible for the production of most of the human scents that are attractive to mosquitoes. Hence, engineering the human skin microbiome to synthesize less of mosquito attractants or produce repellents could potentially reduce bites and prevent the transmission of deadly mosquito-borne pathogens. In order to further characterize the human skin volatilome, we quantified the major volatiles of 39 strains of skin commensals (Staphylococci and Corynebacterium). Importantly, to validate the behavioral activity of these volatiles, we first assessed landing behavior triggered by human skin volatiles. We demonstrated that landing behavior is gated by the presence of carbon dioxide and L-(+)-lactic acid. This is similar to the combinatorial coding triggering mosquito short range attraction. Repellency behavior to selected skin volatiles and terpenes was tested in the presence of carbon dioxide and L-(+)-lactic acid. In a 2-choice landing behavior context, the skin volatiles 2- and 3-methyl butyric acids reduced mosquito landing by 62.0-81.6% and 87.1-99.6%, respectively. Similarly, the terpene geraniol was capable of reducing mosquito landing behavior by 74.9%. We also tested the potential repellency effects of terpenes in mosquitoes at short-range using a 4-port olfactometer. In these assays, geraniol reduced mosquito attraction (69-78%) to a mixture of key human kairomones carbon dioxide, L-(+)-lactic acid, and ammonia. These findings demonstrate that carbon dioxide and L-(+)-lactic acid change the valence of other skin volatiles towards mosquito landing behavior. Moreover, this study offers candidate odorants to be targeted in a novel strategy to reduce attractants or produce repellents by the human skin microbiota that may curtail mosquito bites, and subsequent mosquito-borne disease.
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Affiliation(s)
- Iliano V Coutinho-Abreu
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Omid Jamshidi
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Robyn Raban
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Katayoon Atabakhsh
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Joseph A Merriman
- Sarafan ChEM-H, Stanford University, Stanford, CA, 94305, USA
- Microbiome Therapies Initiative, Stanford University, Palo Alto, CA, 94305, USA
| | - Omar S Akbari
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093, USA.
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9
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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] [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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Terradas G, Macias VM, Peterson H, McKeand S, Krawczyk G, Rasgon JL. The Development and Expansion of in vivo Germline Editing Technologies in Arthropods: Receptor-Mediated Ovary Transduction of Cargo (ReMOT Control) and Beyond. Integr Comp Biol 2023; 63:1550-1563. [PMID: 37742320 PMCID: PMC10755176 DOI: 10.1093/icb/icad123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 08/04/2023] [Accepted: 09/07/2023] [Indexed: 09/26/2023] Open
Abstract
In the past 20 years, sequencing technologies have led to easy access to genomic data from nonmodel organisms in all biological realms. Insect genetic manipulation, however, continues to be a challenge due to various factors, including technical and cost-related issues. Traditional techniques such as microinjection of gene-editing vectors into early stage embryos have been used for arthropod transgenesis and the discovery of Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein (CRISPR-Cas) technologies allowed for targeted mutagenesis and the creation of knockouts or knock-ins in arthropods. Receptor-Mediated Ovary Transduction of Cargo (ReMOT Control) acts as an alternative to embryonic microinjections, which require expensive equipment and extensive hands-on training. ReMOT Control's main advantage is its ease of use coupled with the ability to hypothetically target any vitellogenic species, as injections are administered to the egg-laying adult rather than embryos. After its initial application in the mosquito Aedes aegypti, ReMOT Control has successfully produced mutants not only for mosquitoes but for multiple arthropod species from diverse orders, such as ticks, mites, wasps, beetles, and true bugs, and is being extended to crustaceans, demonstrating the versatility of the technique. In this review, we discuss the current state of ReMOT Control from its proof-of-concept to the advances and challenges in the application across species after 5 years since its development, including novel extensions of the technique such as direct parental (DIPA)-CRISPR.
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Affiliation(s)
- Gerard Terradas
- Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park Pennsylvania, 16802, USA
| | - Vanessa M Macias
- Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park Pennsylvania, 16802, USA
| | - Hillary Peterson
- Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park Pennsylvania, 16802, USA
| | - Sage McKeand
- Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park Pennsylvania, 16802, USA
| | - Grzegorz Krawczyk
- Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park Pennsylvania, 16802, USA
| | - Jason L Rasgon
- Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park Pennsylvania, 16802, USA
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11
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Finda MF, Juma EO, Kahamba NF, Mthawanji RS, Sambo M, Emidi B, Wiener S, O'Brochta D, Santos M, James S, Okumu FO. Perspectives of African stakeholders on gene drives for malaria control and elimination: a multi-country survey. Malar J 2023; 22:384. [PMID: 38129897 PMCID: PMC10740233 DOI: 10.1186/s12936-023-04787-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 11/09/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND Gene drive modified mosquitoes (GDMMs) have the potential to address Africa's persistent malaria problem, but are still in early stages of development and testing. Continuous engagement of African stakeholders is crucial for successful evaluation and implementation of these technologies. The aim of this multi-country study was, therefore, to explore the insights and recommendations of key stakeholders across Africa on the potential of GDMMs for malaria control and elimination in the continent. METHODS A concurrent mixed-methods study design was used, involving a structured survey administered to 180 stakeholders in 25 countries in sub-Saharan Africa, followed by 18 in-depth discussions with selected groups and individuals. Stakeholders were drawn from academia, research and regulatory institutions, government ministries of health and environment, media and advocacy groups. Thematic content analysis was used to identify key topics from the in-depth discussions, and descriptive analysis was done to summarize information from the survey data. RESULTS Despite high levels of awareness of GDMMs among the stakeholders (76.7%), there was a relatively low-level of understanding of their key attributes and potential for malaria control (28.3%). When more information about GDMMs was provided to the stakeholders, they readily discussed their insights and concerns, and offered several recommendations to ensure successful research and implementation of the technology. These included: (i) increasing relevant technical expertise within Africa, (ii) generating local evidence on safety, applicability, and effectiveness of GDMMs, and (iii) developing country-specific regulations for safe and effective governance of GDMMs. A majority of the respondents (92.9%) stated that they would support field trials or implementation of GDMMs in their respective countries. This study also identified significant misconceptions regarding the phase of GDMM testing in Africa, as several participants incorrectly asserted that GDMMs were already present in Africa, either within laboratories or released into the field. CONCLUSION Incorporating views and recommendations of African stakeholders in the ongoing research and development of GDMMs is crucial for instilling stakeholder confidence on their potential application. These findings will enable improved planning for GDMMs in Africa as well as improved target product profiles for the technologies to maximize their potential for solving Africa's enduring malaria challenge.
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Affiliation(s)
- Marceline F Finda
- Environmental Health and Ecological Sciences, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania.
| | - Elijah O Juma
- Pan-African Mosquito Control Association (PAMCA), Off Mbagathi Road, PO Box 44455-00100, Nairobi, Kenya
| | - Najat F Kahamba
- Environmental Health and Ecological Sciences, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania
| | - Rhosheen S Mthawanji
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre 3, PO Box 30096, Chichiri, Malawi
| | - Maganga Sambo
- Environmental Health and Ecological Sciences, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania
| | - Basiliana Emidi
- National Institute for Medical Research, PO Box 1462, Mwanza, Tanzania
| | - Susan Wiener
- Foundation for the National Institutes of Health, 11400 Rockville Pike, Suite 600, North Bethesda, MD, 20852, USA
| | - David O'Brochta
- Foundation for the National Institutes of Health, 11400 Rockville Pike, Suite 600, North Bethesda, MD, 20852, USA
| | - Michael Santos
- Foundation for the National Institutes of Health, 11400 Rockville Pike, Suite 600, North Bethesda, MD, 20852, USA
| | - Stephanie James
- Foundation for the National Institutes of Health, 11400 Rockville Pike, Suite 600, North Bethesda, MD, 20852, USA
| | - Fredros O Okumu
- Environmental Health and Ecological Sciences, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania
- School of Life Science and Bioengineering, The Nelson Mandela African Institution of Science and Technology, P. O. Box 447, Arusha, Tanzania
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, G128QQ, UK
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, 1 Smuts Avenue, Braamofontein, 2000, South Africa
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12
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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] [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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13
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Raban R, Marshall JM, Hay BA, Akbari OS. Manipulating the Destiny of Wild Populations Using CRISPR. Annu Rev Genet 2023; 57:361-390. [PMID: 37722684 PMCID: PMC11064769 DOI: 10.1146/annurev-genet-031623-105059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
Genetic biocontrol aims to suppress or modify populations of species to protect public health, agriculture, and biodiversity. Advancements in genome engineering technologies have fueled a surge in research in this field, with one gene editing technology, CRISPR, leading the charge. This review focuses on the current state of CRISPR technologies for genetic biocontrol of pests and highlights the progress and ongoing challenges of using these approaches.
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Affiliation(s)
- Robyn Raban
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California, San Diego, La Jolla, California, USA;
| | - John M Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, USA
| | - Bruce A Hay
- Division of Biology and Biological Engineering (BBE), California Institute of Technology, Pasadena, California, USA
| | - Omar S Akbari
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California, San Diego, La Jolla, California, USA;
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14
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Chennuri PR, Zapletal J, Monfardini RD, Ndeffo-Mbah ML, Adelman ZN, Myles KM. Repeat mediated excision of gene drive elements for restoring wild-type populations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.23.568397. [PMID: 38045402 PMCID: PMC10690251 DOI: 10.1101/2023.11.23.568397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
We demonstrate here that single strand annealing (SSA) repair can be co-opted for the precise autocatalytic excision of a drive element. Although SSA is not the predominant form of DNA repair in eukaryotic organisms, we increased the likelihood of its use by engineering direct repeats at sites flanking the drive allele, and then introducing a double-strand DNA break (DSB) at a second endonuclease target site encoded within the drive allele. We have termed this technology Re peat M ediated E xcision of a D rive E lement (ReMEDE). Incorporation of ReMEDE into the previously described mutagenic chain reaction (MCR) gene drive, targeting the yellow gene of Drosophila melanogaster , replaced drive alleles with wild-type alleles demonstrating proof-of-principle. Although the ReMEDE system requires further research and development, the technology has a number of attractive features as a gene drive mitigation strategy, chief among these the potential to restore a wild-type population without releasing additional transgenic organisms or large-scale environmental engineering efforts.
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15
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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: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [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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16
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Kormos A, Dimopoulos G, Bier E, Lanzaro GC, Marshall JM, James AA. Conceptual risk assessment of mosquito population modification gene-drive systems to control malaria transmission: preliminary hazards list workshops. Front Bioeng Biotechnol 2023; 11:1261123. [PMID: 37965050 PMCID: PMC10641379 DOI: 10.3389/fbioe.2023.1261123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 10/09/2023] [Indexed: 11/16/2023] Open
Abstract
The field-testing and eventual adoption of genetically-engineered mosquitoes (GEMs) to control vector-borne pathogen transmission will require them meeting safety criteria specified by regulatory authorities in regions where the technology is being considered for use and other locales that might be impacted. Preliminary risk considerations by researchers and developers may be useful for planning the baseline data collection and field research used to address the anticipated safety concerns. Part of this process is to identify potential hazards (defined as the inherent ability of an entity to cause harm) and their harms, and then chart the pathways to harm and evaluate their probability as part of a risk assessment. The University of California Malaria Initiative (UCMI) participated in a series of workshops held to identify potential hazards specific to mosquito population modification strains carrying gene-drive systems coupled to anti-parasite effector genes and their use in a hypothetical island field trial. The hazards identified were placed within the broader context of previous efforts discussed in the scientific literature. Five risk areas were considered i) pathogens, infections and diseases, and the impacts of GEMs on human and animal health, ii) invasiveness and persistence of GEMs, and interactions of GEMs with target organisms, iii) interactions of GEMs with non-target organisms including horizontal gene transfer, iv) impacts of techniques used for the management of GEMs and v) evolutionary and stability considerations. A preliminary hazards list (PHL) was developed and is made available here. This PHL is useful for internal project risk evaluation and is available to regulators at prospective field sites. UCMI project scientists affirm that the subsequent processes associated with the comprehensive risk assessment for the application of this technology should be driven by the stakeholders at the proposed field site and areas that could be affected by this intervention strategy.
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Affiliation(s)
- Ana Kormos
- Vector Genetics Laboratory, University of California, Davis, Davis, CA, United States
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Malaria Research Institute, Johns Hopkins University, Baltimore, MD, United States
| | - Ethan Bier
- Department of Cell and Developmental Biology, University of California, San Diego, San Diego, CA, United States
| | - Gregory C. Lanzaro
- Vector Genetics Laboratory, University of California, Davis, Davis, CA, United States
| | - John M. Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, CA, United States
| | - Anthony A. James
- Departments of Microbiology and Molecular Genetics and Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, United States
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17
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Sanz Juste S, Okamoto EM, Nguyen C, Feng X, López Del Amo V. Next-generation CRISPR gene-drive systems using Cas12a nuclease. Nat Commun 2023; 14:6388. [PMID: 37821497 PMCID: PMC10567717 DOI: 10.1038/s41467-023-42183-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 10/03/2023] [Indexed: 10/13/2023] Open
Abstract
One method for reducing the impact of vector-borne diseases is through the use of CRISPR-based gene drives, which manipulate insect populations due to their ability to rapidly propagate desired genetic traits into a target population. However, all current gene drives employ a Cas9 nuclease that is constitutively active, impeding our control over their propagation abilities and limiting the generation of alternative gene drive arrangements. Yet, other nucleases such as the temperature sensitive Cas12a have not been explored for gene drive designs in insects. To address this, we herein present a proof-of-concept gene-drive system driven by Cas12a that can be regulated via temperature modulation. Furthermore, we combined Cas9 and Cas12a to build double gene drives capable of simultaneously spreading two independent engineered alleles. The development of Cas12a-mediated gene drives provides an innovative option for designing next-generation vector control strategies to combat disease vectors and agricultural pests.
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Affiliation(s)
- Sara Sanz Juste
- Department of Epigenetics & Molecular Carcinogenesis at MD Anderson, The University of Texas MD Anderson Cancer Center, Houston, TX, 77054, USA
- Center for Cancer Epigenetics, MD Anderson Cancer Center, Houston, TX, 77054, USA
| | - Emily M Okamoto
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Christina Nguyen
- University of Texas Health Science Center, School of Public Health, Department of Epidemiology, Human Genetics, and Environmental Sciences, Center for Infectious Diseases, Houston, TX, 77030, USA
| | - 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, Shenzhen, Guangdong, 518106, China.
| | - Víctor López Del Amo
- University of Texas Health Science Center, School of Public Health, Department of Epidemiology, Human Genetics, and Environmental Sciences, Center for Infectious Diseases, Houston, TX, 77030, USA.
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18
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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] [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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19
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Pan M, Champer J. Making waves: Comparative analysis of gene drive spread characteristics in a continuous space model. Mol Ecol 2023; 32:5673-5694. [PMID: 37694511 DOI: 10.1111/mec.17131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 08/16/2023] [Accepted: 08/31/2023] [Indexed: 09/12/2023]
Abstract
With their ability to rapidly increase in frequency, gene drives can be used to modify or suppress target populations after an initial release of drive individuals. Recent advances have revealed many possibilities for different types of drives, and several of these have been realized in experiments. These drives have advantages and disadvantages related to their ease of construction, confinement and capacity to be used for modification or suppression. Though characteristics of these drives have been explored in modelling studies, assessment in continuous space environments has been limited, often focusing on outcomes rather than fundamental properties. Here, we conduct a comparative analysis of many different gene drive types that have the capacity to form a wave of advance in continuous space using individual-based simulations in continuous space. We evaluate the drive wave speed as a function of drive performance and ecological parameters, which reveals substantial differences between drive performance in panmictic versus spatial environments. In particular, we find that suppression drive waves are uniquely vulnerable to fitness costs and undesired CRISPR cleavage activity in embryos by maternal deposition. Some drives, however, retain robust performance even with widely varying efficiency parameters. To gain a better understanding of drive waves, we compare their panmictic performance and find that the rate of wild-type allele removal is correlated with drive wave speed, though this is also affected by other factors. Overall, our results provide a useful resource for understanding the performance of drives in spatially continuous environments, which may be most representative of potential drive deployment in many relevant scenarios.
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Affiliation(s)
- Mingzuyu Pan
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, Beijing, China
| | - Jackson Champer
- Center for Bioinformatics, School of Life Sciences, Center for Life Sciences, Peking University, Beijing, China
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20
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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 ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2023; 43:1921-1932. [PMID: 36693350 DOI: 10.1111/risa.14096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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21
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Menchaca A. Assisted Reproductive Technologies (ART) and genome editing to support a sustainable livestock. Anim Reprod 2023; 20:e20230074. [PMID: 37720722 PMCID: PMC10503885 DOI: 10.1590/1984-3143-ar2023-0074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/21/2023] [Indexed: 09/19/2023] Open
Abstract
This article provides an overview of assisted reproductive technologies (ART) and genome engineering to improve livestock production systems for the contribution of global sustainability. Most ruminant production systems are conducted on grassland conditions, as is the case of South American countries that are leaders in meat and milk production worldwide with a well-established grass-feed livestock. These systems have many strengths from an environmental perspective and consumer preferences but requires certain improvements to enhance resource efficiency. Reproductive performance is one of the main challenges particularly in cow-calf operations that usually are conducted under adverse conditions and thus ART can make a great contribution. Fixed-time artificial insemination is applied in South America in large scale programs as 20 to 30% of cows receive this technology every year in each country, with greater calving rate and significant herd genetic gain occurred in this region. Sexed semen has also been increasingly implemented, enhancing resource efficiency by a) obtaining desired female replacement and improving animal welfare by avoiding newborn male sacrifice in dairy industry, or b) alternatively producing male calves for beef industry. In vitro embryo production has been massively applied, with this region showing the greatest number of embryos produced worldwide leading to significant improvement in herd genetics and productivity. Although the contribution of these technologies is considerable, further improvements will be required for a significant livestock transformation and novel biotechnologies such as genome editing are already available. Through the CRISPR/Cas-based system it is possible to enhance food yield and quality, avoid animal welfare concerns, overcome animal health threats, and control pests and invasive species harming food production. In summary, a significant enhancement in livestock productivity and resource efficiency can be made through reproductive technologies and genome editing, improving at the same time profitability for farmers, and global food security and sustainability.
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Affiliation(s)
- Alejo Menchaca
- Plataforma de Salud Animal, Instituto Nacional de Investigación Agropecuaria, Montevideo, Uruguay
- Fundación Instituto de Reproducción Animal Uruguay, Montevideo, Uruguay
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22
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Coutinho-Abreu IV, Jamshidi O, Raban R, Atabakhsh K, Merriman JA, Fischbach MA, Akbari OS. Identification of human skin microbiome odorants that manipulate mosquito landing behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.19.553996. [PMID: 37662338 PMCID: PMC10473644 DOI: 10.1101/2023.08.19.553996] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
The resident human skin microbiome is responsible for the production of most of the human scents that are attractive to mosquitoes. Hence, engineering the human skin microbiome to synthesize less of mosquito attractants or produce repellents could potentially reduce bites and prevent the transmission of deadly mosquito-borne pathogens. In order to further characterize the human skin volatilome, we quantified the major volatiles of 39 strains of skin commensals (Staphylococci and Corynebacterium). Importantly, to validate the behavioral activity of these volatiles, we first assessed landing behavior triggered by human skin bacteria volatiles. We demonstrated that this behavioral step is gated by the presence of carbon dioxide and L-(+)-lactic acid, similar to the combinatorial coding triggering short range attraction. Repellency behavior to selected skin volatiles and the geraniol terpene was tested in the presence of carbon dioxide and L-(+)-lactic acid. In a 2-choice landing behavior context, the skin volatiles 2- and 3-methyl butyric acids reduced mosquito landing by 62.0-81.6% and 87.1-99.6%, respectively. Similarly, geraniol was capable of reducing mosquito landing behavior by 74.9%. We also tested the potential repellency effects of geraniol on mosquitoes at short-range using a 4-port olfactometer. In these assays, geraniol reduced mosquito attraction (69-78%) to a mixture of key human kairomones carbon dioxide, L-(+)-lactic acid, and ammonia. These findings demonstrate that carbon dioxide and L-(+)-lactic acid changes the valence of other skin volatiles towards mosquito landing behavior. Moreover, this study offers candidate odorants to be targeted in a novel strategy to reduce attractants or produce repellents by the human skin microbiota that may curtail mosquito bites, and subsequent mosquito-borne disease.
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Affiliation(s)
- Iliano V. Coutinho-Abreu
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093
| | - Omid Jamshidi
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093
| | - Robyn Raban
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093
| | - Katayoon Atabakhsh
- Department of Bioengineering Stanford University, Stanford, CA 94305, USA
| | - Joseph A. Merriman
- Sarafan ChEM-H, Stanford University, Stanford, CA 94305, USA
- Microbiome Therapies Initiative, Stanford University, Palo Alto, CA 94305, USA
| | - Michael A. Fischbach
- Department of Bioengineering Stanford University, Stanford, CA 94305, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA 94305, USA
- Microbiome Therapies Initiative, Stanford University, Palo Alto, CA 94305, USA
| | - Omar S. Akbari
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093
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23
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Page N, Taxiarchi C, Tonge D, Kuburic J, Chesters E, Kriezis A, Kyrou K, Game L, Nolan T, Galizi R. Single-cell profiling of Anopheles gambiae spermatogenesis defines the onset of meiotic silencing and premeiotic overexpression of the X chromosome. Commun Biol 2023; 6:850. [PMID: 37582841 PMCID: PMC10427639 DOI: 10.1038/s42003-023-05224-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/07/2023] [Indexed: 08/17/2023] Open
Abstract
Understanding development and genetic regulation in the Anopheles gambiae germline is essential to engineer effective genetic control strategies targeting this malaria mosquito vector. These include targeting the germline to induce sterility or using regulatory sequences to drive transgene expression for applications such as gene drive. However, only very few germline-specific regulatory elements have been characterised with the majority showing leaky expression. This has been shown to considerably reduce the efficiency of current genetic control strategies, which rely on regulatory elements with more tightly restricted spatial and/or temporal expression. Meiotic silencing of the sex chromosomes limits the flexibility of transgene expression to develop effective sex-linked genetic control strategies. Here, we build on our previous study, dissecting gametogenesis into four distinct cell populations, using single-cell RNA sequencing to define eight distinct cell clusters and associated germline cell-types using available marker genes. We reveal overexpression of X-linked genes in a distinct cluster of pre-meiotic cells and document the onset of meiotic silencing of the X chromosome in a subcluster of cells in the latter stages of spermatogenesis. This study provides a comprehensive dataset, characterising the expression of distinct cell types through spermatogenesis and widening the toolkit for genetic control of malaria mosquitoes.
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Affiliation(s)
- Nicole Page
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Daniel Tonge
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Keele, UK
| | - Jasmina Kuburic
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Keele, UK
| | - Emily Chesters
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Keele, UK
| | - Antonios Kriezis
- Department of Life Sciences, Imperial College London, London, UK
| | - Kyros Kyrou
- Department of Life Sciences, Imperial College London, London, UK
| | - Laurence Game
- Genomics Facility, MRC London Institute of Medical Sciences, Imperial College London, London, United Kingdom
| | - Tony Nolan
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Roberto Galizi
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Keele, UK.
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Carballar-Lejarazú R, Dong Y, Pham TB, Tushar T, Corder RM, Mondal A, Sánchez C. HM, Lee HF, Marshall JM, Dimopoulos G, James AA. Dual effector population modification gene-drive strains of the African malaria mosquitoes, Anopheles gambiae and Anopheles coluzzii. Proc Natl Acad Sci U S A 2023; 120:e2221118120. [PMID: 37428915 PMCID: PMC10629562 DOI: 10.1073/pnas.2221118120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 06/05/2023] [Indexed: 07/12/2023] Open
Abstract
Proposed genetic approaches for reducing human malaria include population modification, which introduces genes into vector mosquitoes to reduce or prevent parasite transmission. We demonstrate the potential of Cas9/guide RNA (gRNA)-based gene-drive systems linked to dual antiparasite effector genes to spread rapidly through mosquito populations. Two strains have an autonomous gene-drive system coupled to dual anti-Plasmodium falciparum effector genes comprising single-chain variable fragment monoclonal antibodies targeting parasite ookinetes and sporozoites in the African malaria mosquitoes Anopheles gambiae (AgTP13) and Anopheles coluzzii (AcTP13). The gene-drive systems achieved full introduction within 3 to 6 mo after release in small cage trials. Life-table analyses revealed no fitness loads affecting AcTP13 gene-drive dynamics but AgTP13 males were less competitive than wild types. The effector molecules reduced significantly both parasite prevalence and infection intensities. These data supported transmission modeling of conceptual field releases in an island setting that shows meaningful epidemiological impacts at different sporozoite threshold levels (2.5 to 10 k) for human infection by reducing malaria incidence in optimal simulations by 50 to 90% within as few as 1 to 2 mo after a series of releases, and by ≥90% within 3 mo. Modeling outcomes for low sporozoite thresholds are sensitive to gene-drive system fitness loads, gametocytemia infection intensities during parasite challenges, and the formation of potentially drive-resistant genome target sites, extending the predicted times to achieve reduced incidence. TP13-based strains could be effective for malaria control strategies following validation of sporozoite transmission threshold numbers and testing field-derived parasite strains. These or similar strains are viable candidates for future field trials in a malaria-endemic region.
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Affiliation(s)
| | - Yuemei Dong
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Malaria Research Institute, Johns Hopkins University, Baltimore, MD21205
| | - Thai Binh Pham
- Department of Microbiology & Molecular Genetics, University of California, Irvine, CA92697-4025
| | - Taylor Tushar
- Department of Microbiology & Molecular Genetics, University of California, Irvine, CA92697-4025
| | - Rodrigo M. Corder
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA94720
| | - Agastya Mondal
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA94720
| | - Héctor M. Sánchez C.
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA94720
| | - Hsu-Feng Lee
- Department of Microbiology & Molecular Genetics, University of California, Irvine, CA92697-4025
| | - John M. Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA94720
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Malaria Research Institute, Johns Hopkins University, Baltimore, MD21205
| | - Anthony A. James
- Department of Microbiology & Molecular Genetics, University of California, Irvine, CA92697-4025
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA92697-3900
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Jia Z, Hasi S, Zhan D, Hou B, Vogl C, Burger PA. Genome and Transcriptome Analyses Facilitate Genetic Control of Wohlfahrtia magnifica, a Myiasis-Causing Flesh Fly. INSECTS 2023; 14:620. [PMID: 37504626 PMCID: PMC10380434 DOI: 10.3390/insects14070620] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/29/2023] [Accepted: 07/04/2023] [Indexed: 07/29/2023]
Abstract
Myiasis caused by Wohlfahrtia magnifica is a widespread parasitic infestation in mammals. The infested host suffers from damage as the developing larvae feed on its tissues. For the control of myiasis infestation, genetic methods have been shown to be effective and promising as an alternative to insecticides. Combining genome, isoform sequencing (Iso-Seq), and RNA sequencing (RNA-seq) data, we isolated and characterized two sex-determination genes, W. magnifica transformer (Wmtra) and W. magnifica transformer2 (Wmtra2), whose orthologs in a number of insect pests have been utilized to develop genetic control approaches. Wmtra transcripts are sex-specifically spliced; only the female transcript encodes a full-length functional protein, while the male transcript encodes a truncated and non-functional polypeptide due to the presence of the male-specific exon containing multiple in-frame stop codons. The existence of five predicted TRA/TRA2 binding sites in the male-specific exon and the surrounding intron of Wmtra, as well as the presence of an RNA-recognition motif in WmTRA2 may suggest the auto-regulation of Wmtra by its own protein interacting with WmTRA2. This results in the skipping of the male-specific exon and translation of the full-length functional protein only in females. Our comparative study in dipteran species showed that both the WmTRA and WmTRA2 proteins exhibit a high degree of similarity to their orthologs in the myiasis-causing blow flies. Additionally, transcriptome profiling performed between adult females and adult males reported 657 upregulated and 365 downregulated genes. Functional analysis showed that among upregulated genes those related to meiosis and mitosis Gene Ontology (GO) terms were enriched, while, among downregulated genes, those related to muscle cell development and aerobic metabolic processes were enriched. Among the female-biased gene set, we detected five candidate genes, vasa (vas), nanos (nanos), bicoid (bcd), Bicaudal C (BicC), and innexin5 (inx5). The promoters of these genes may be able to upregulate Cas9 expression in the germline in Cas9-based homing gene drive systems as established in some flies and mosquitoes. The isolation and characterization of these genes is an important step toward the development of genetic control programs against W. magnifica infestation.
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Affiliation(s)
- Zhipeng Jia
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Savoyenstrasse 1, 1160 Vienna, Austria
| | - Surong Hasi
- Key Laboratory of Clinical Diagnosis and Treatment Technology in Animal Disease, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Deng Zhan
- Key Laboratory of Clinical Diagnosis and Treatment Technology in Animal Disease, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Bin Hou
- Key Laboratory of Clinical Diagnosis and Treatment Technology in Animal Disease, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Claus Vogl
- Institute of Animal Breeding and Genetics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria
| | - Pamela A Burger
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Savoyenstrasse 1, 1160 Vienna, Austria
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Sánchez C. HM, Smith DL, Marshall JM. MGSurvE: A framework to optimize trap placement for genetic surveillance of mosquito population. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.26.546301. [PMID: 37425729 PMCID: PMC10327167 DOI: 10.1101/2023.06.26.546301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Genetic surveillance of mosquito populations is becoming increasingly relevant as genetics-based mosquito control strategies advance from laboratory to field testing. Especially applicable are mosquito gene drive projects, the potential scale of which leads monitoring to be a significant cost driver. For these projects, monitoring will be required to detect unintended spread of gene drive mosquitoes beyond field sites, and the emergence of alternative alleles, such as drive-resistant alleles or non-functional effector genes, within intervention sites. This entails the need to distribute mosquito traps efficiently such that an allele of interest is detected as quickly as possible - ideally when remediation is still viable. Additionally, insecticide-based tools such as bednets are compromised by insecticide-resistance alleles for which there is also a need to detect as quickly as possible. To this end, we present MGSurvE (Mosquito Gene SurveillancE): a computational framework that optimizes trap placement for genetic surveillance of mosquito populations such that the time to detection of an allele of interest is minimized. A key strength of MGSurvE is that it allows important biological features of mosquitoes and the landscapes they inhabit to be accounted for, namely: i) resources required by mosquitoes (e.g., food sources and aquatic breeding sites) can be explicitly distributed through a landscape, ii) movement of mosquitoes may depend on their sex, the current state of their gonotrophic cycle (if female) and resource attractiveness, and iii) traps may differ in their attractiveness profile. Example MGSurvE analyses are presented to demonstrate optimal trap placement for: i) an Aedes aegypti population in a suburban landscape in Queensland, Australia, and ii) an Anopheles gambiae population on the island of São Tomé, São Tomé and Príncipe. Further documentation and use examples are provided in project's documentation. MGSurvE is freely available as an open-source Python package on pypi (https://pypi.org/project/MGSurvE/). It is intended as a resource for both field and computational researchers interested in mosquito gene surveillance.
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Affiliation(s)
- Héctor M. Sánchez C.
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - David L. Smith
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
- Department of Health Metrics Sciences, School of Medicine, University of Washington, Seattle, WA, USA
| | - John M. Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
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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. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.12.544656. [PMID: 37398284 PMCID: PMC10312623 DOI: 10.1101/2023.06.12.544656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
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 the first CRISPR-based homing gene drive for Culex quinquefasciatus, demonstrating the possibility of using this technology to control Culex mosquitoes. Our results 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, UK, GU24 0NF
| | - Xuechun Feng
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA 92093
| | - Emily M Okamoto
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA 92093
| | - Deepak-Kumar Purusothaman
- Arthropod Genetics Group, The Pirbright Institute, Woking, UK, GU24 0NF
- Present address: MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, UK G12 8QQ
| | - Philip T Leftwich
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK, NR4 7TJ
| | - Luke Alphey
- Present address: Biology Department, University of York, York, UK, YO10 5DD
| | - Valentino M Gantz
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA 92093
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James SL, Quemada H, Benedict MQ, Dass B. Requirements for market entry of gene drive-modified mosquitoes for control of vector-borne diseases: analogies to other biologic and biotechnology products. Front Bioeng Biotechnol 2023; 11:1205865. [PMID: 37362219 PMCID: PMC10285705 DOI: 10.3389/fbioe.2023.1205865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/25/2023] [Indexed: 06/28/2023] Open
Abstract
Gene drive-modified mosquitoes (GDMMs) are proposed as new tools for control and elimination of malaria and other mosquito-borne diseases, and promising results have been observed from testing conducted in containment. Although still at an early stage of development, it is important to begin now to consider approval procedures and market entry strategies for the eventual implementation of GDMMs in the context of disease control programs, as these could impact future research plans. It is expected that, as for other types of new products, those seeking to bring GDMMs to market will be required to provide sufficient information to allow the regulator(s) to determine whether the product is safe and effective for its proposed use. There already has been much emphasis on developing requirements for the biosafety components of the "safe and effective" benchmark, largely concerned with their regulation as genetically modified organisms. Other potential approval requirements have received little attention, however. Although GDMMs are expected to be implemented primarily in the context of public health programs, any regulatory analogies to other public health products, such as pharmaceuticals, vaccines, or chemical pesticides, must take into account the characteristics of live mosquito products. Typical manufacturing standards related to product identity, potency or quality will need to be adapted to GDMMs. Valuable lessons can be drawn from the regulatory approval processes for other whole organism and genetically modified (GM) organism products. Supply chain requirements, such as scale of production, location and design of production facilities, and methods of distribution and delivery, will be dependent upon the characteristics of the particular GDMM product, the conditions of use, and the region to be served. Plans for fulfilling supply chain needs can build upon experience in the development of other live insect products for use in public health and agriculture. Implementation of GDMMs would benefit from additional research on enabling technologies for long-term storage of mosquito life stages, efficient mass production, and area-wide delivery of GDMMs. Early consideration of these practical requirements for market entry will help to mitigate downstream delays in the development of these promising new technologies.
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Affiliation(s)
- Stephanie L. James
- GeneConvene Global Collaborative, Foundation for the NIH, Bethesda, MD, United States
| | | | | | - Brinda Dass
- GeneConvene Global Collaborative, Foundation for the NIH, Bethesda, MD, United States
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Nourani L, Mehrizi AA, Pirahmadi S, Pourhashem Z, Asadollahi E, Jahangiri B. CRISPR/Cas advancements for genome editing, diagnosis, therapeutics, and vaccine development for Plasmodium parasites, and genetic engineering of Anopheles mosquito vector. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2023; 109:105419. [PMID: 36842543 DOI: 10.1016/j.meegid.2023.105419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/30/2023] [Accepted: 02/21/2023] [Indexed: 02/28/2023]
Abstract
Malaria as vector-borne disease remains important health concern with over 200 million cases globally. Novel antimalarial medicines and more effective vaccines must be developed to eliminate and eradicate malaria. Appraisal of preceding genome editing approaches confirmed the CRISPR/Cas nuclease system as a novel proficient genome editing system and a tool for species-specific diagnosis, and drug resistance researches for Plasmodium species, and gene drive to control Anopheles population. CRISPR/Cas technology, as a handy tool for genome editing can be justified for the production of transgenic malaria parasites like Plasmodium transgenic lines expressing Cas9, chimeric Plasmodium transgenic lines, knockdown and knockout transgenic parasites, and transgenic parasites expressing alternative alleles, and also mutant strains of Anopheles such as only male mosquito populations, generation of wingless mosquitoes, and creation of knock-out/ knock-in mutants. Though, the incorporation of traditional methods and novel molecular techniques could noticeably enhance the quality of results. The striking development of a CRISPR/Cas-based diagnostic kit that can specifically diagnose the Plasmodium species or drug resistance markers is highly required in malaria settings with affordable cost and high-speed detection. Furthermore, the advancement of genome modifications by CRISPR/Cas technologies resolves contemporary restrictions to culturing, maintaining, and analyzing these parasites, and the aptitude to investigate parasite genome functions opens up new vistas in the better understanding of pathogenesis.
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Affiliation(s)
- Leila Nourani
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Akram Abouie Mehrizi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran.
| | - Sakineh Pirahmadi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Zeinab Pourhashem
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Elahe Asadollahi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Babak Jahangiri
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
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James S, Santos M. The Promise and Challenge of Genetic Biocontrol Approaches for Malaria Elimination. Trop Med Infect Dis 2023; 8:201. [PMID: 37104327 PMCID: PMC10140850 DOI: 10.3390/tropicalmed8040201] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/15/2023] [Accepted: 03/23/2023] [Indexed: 04/03/2023] Open
Abstract
Malaria remains an ongoing public health challenge, with over 600,000 deaths in 2021, of which approximately 96% occurred in Africa. Despite concerted efforts, the goal of global malaria elimination has stalled in recent years. This has resulted in widespread calls for new control methods. Genetic biocontrol approaches, including those focused on gene-drive-modified mosquitoes (GDMMs), aim to prevent malaria transmission by either reducing the population size of malaria-transmitting mosquitoes or making the mosquitoes less competent to transmit the malaria parasite. The development of both strategies has advanced considerably in recent years, with successful field trials of several biocontrol methods employing live mosquito products and demonstration of the efficacy of GDMMs in insectary-based studies. Live mosquito biocontrol products aim to achieve area-wide control with characteristics that differ substantially from current insecticide-based vector control methods, resulting in some different considerations for approval and implementation. The successful field application of current biocontrol technologies against other pests provides evidence for the promise of these approaches and insights into the development pathway for new malaria control agents. The status of technical development as well as current thinking on the implementation requirements for genetic biocontrol approaches are reviewed, and remaining challenges for public health application in malaria prevention are discussed.
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Affiliation(s)
- Stephanie James
- Foundation for the National Institutes of Health, North Bethesda, MD 20852, USA
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Zhu Y, Champer J. Simulations Reveal High Efficiency and Confinement of a Population Suppression CRISPR Toxin-Antidote Gene Drive. ACS Synth Biol 2023; 12:809-819. [PMID: 36825354 DOI: 10.1021/acssynbio.2c00611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Though engineered gene drives hold great promise for spreading through and suppressing populations of disease vectors or invasive species, complications such as resistance alleles and spatial population structure can prevent their success. Additionally, most forms of suppression drives, such as homing drives or driving Y chromosomes, will generally spread uncontrollably between populations with even small levels of migration. The previously proposed CRISPR-based toxin-antidote system called toxin-antidote dominant embryo (TADE) suppression drive could potentially address the issues of confinement and resistance. However, it is a relatively weak form of drive compared to homing drives, which might make it particularly vulnerable to spatial population structure. In this study, we investigate TADE suppression drive using individual-based simulations in a continuous spatial landscape. We find that the drive is actually more confined than in simple models without space, even in its most efficient form with low cleavage rate in embryos from maternally deposited Cas9. Furthermore, the drive performed well in continuous space scenarios if the initial release requirements were met, suppressing the population in a timely manner without being severely affected by chasing, a phenomenon in which wild-type individuals avoid the drive by recolonizing empty areas. At higher embryo cut rates, the drive loses its ability to spread, but a single, widespread release can often still induce rapid population collapse. Thus, if TADE suppression gene drives can be successfully constructed, they may play an important role in control of disease vectors and invasive species when stringent confinement to target populations is desired.
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Affiliation(s)
- Yutong Zhu
- Center for Bioinformatics, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Jackson Champer
- Center for Bioinformatics, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
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Das S, Máquina M, Phillips K, Cuamba N, Marrenjo D, Saúte F, Paaijmans KP, Huijben S. Fine-scale spatial distribution of deltamethrin resistance and population structure of Anopheles funestus and Anopheles arabiensis populations in Southern Mozambique. Malar J 2023; 22:94. [PMID: 36915131 PMCID: PMC10010967 DOI: 10.1186/s12936-023-04522-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/03/2023] [Indexed: 03/16/2023] Open
Abstract
BACKGROUND Insecticide resistance in malaria vectors can be spatially highly heterogeneous, yet population structure analyses frequently find relatively high levels of gene flow among mosquito populations. Few studies have contemporaneously assessed phenotypic, genotypic and population structure analysis on mosquito populations and none at fine geographical scales. In this study, genetic diversity, population structure, and insecticide resistance profiles of Anopheles funestus and Anopheles arabiensis were examined across mosquito populations from and within neighbouring villages. METHODS Mosquitoes were collected from 11 towns in southern Mozambique, as well as from different neighbourhoods within the town of Palmeira, during the peak malaria transmission season in 2016. CDC bottle bioassay and PCR assays were performed with Anopheles mosquitoes at each site to determine phenotypic and molecular insecticide resistance profiles, respectively. Microsatellite analysis was conducted on a subsample of mosquitoes to estimate genetic diversity and population structure. RESULTS Phenotypic insecticide resistance to deltamethrin was observed in An. funestus sensu stricto (s.s.) throughout the area, though a high level of mortality variation was seen. However, 98% of An. funestus s.s. were CYP6P9a homozygous resistant. An. arabiensis was phenotypically susceptible to deltamethrin and 99% were kdr homozygous susceptible. Both Anopheles species exhibited high allelic richness and heterozygosity. Significant deviations from Hardy-Weinberg equilibrium were observed, and high linkage disequilibrium was seen for An. funestus s.s., supporting population subdivision. However, the FST values were low for both anophelines (- 0.00457 to 0.04213), Nm values were high (9.4-71.8 migrants per generation), AMOVA results showed almost 100% genetic variation among and within individuals, and Structure analysis showed no clustering of An. funestus s.s. and An. arabiensis populations. These results suggest high gene flow among mosquito populations. CONCLUSION Despite a relatively high level of phenotypic variation in the An. funestus population, molecular analysis shows the population is admixed. These data indicate that CYP6P9a resistance markers do not capture all phenotypic variation in the area, but also that resistance genes of high impact are likely to easily spread in the area. Conversely, other strategies, such as transgenic mosquito release programmes will likely not face challenges in this locality.
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Affiliation(s)
- Smita Das
- The Center for Evolution & Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, USA
- PATH, Seattle, WA, USA
| | - Mara Máquina
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Manhica, Mozambique
| | - Keeley Phillips
- The Center for Evolution & Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Nelson Cuamba
- Programa Nacional de Controlo da Malária, Ministério da Saúde, Maputo, Mozambique
- PMI VectorLink Project, Abt Associates Inc., Maputo, Mozambique
| | - Dulcisaria Marrenjo
- Programa Nacional de Controlo da Malária, Ministério da Saúde, Maputo, Mozambique
| | - Francisco Saúte
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Manhiça, Manhica, Mozambique
| | - Krijn P Paaijmans
- The Center for Evolution & Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Simon A. Levin Mathematical, Computational and Modeling Sciences Center, Arizona State University, Tempe, AZ, USA
- The Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ, USA
- ISGlobal, Barcelona, Spain
| | - Silvie Huijben
- The Center for Evolution & Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, USA.
- Simon A. Levin Mathematical, Computational and Modeling Sciences Center, Arizona State University, Tempe, AZ, USA.
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Fu J, Li L, Dai C, Zhang Y, Hu Y, Hu C, Li H. Transcriptomic analysis of Mythimna separata ovaries and identification of genes involved in reproduction. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY PART D: GENOMICS AND PROTEOMICS 2023; 46:101075. [PMID: 37031498 DOI: 10.1016/j.cbd.2023.101075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023]
Abstract
The migratory insect Mythimna separata is a major pest of grain crops in Asia. Unfortunately, the molecular mechanisms that control and regulate reproduction in this species remain unclear. In this study, transcriptome sequencing was utilized to identify genes associated with ovary development and oogenesis. Clean sequences totaling 117.71 Gb were assembled into 178,534 unigenes with a mean length of 647.37 bp and N50 length of 837 bp. Transcriptome analysis showed that 7921 unigenes were significantly expressed in ovaries with 4403 and 3518 unigenes up- and down-regulated, respectively. Enrichment analysis with the Kyoto Encyclopedia of Genes and Genomes database suggested that 729 differentially expressed genes were significantly enriched in the top 20 pathways (q-values <0.05). Twenty genes were associated with ovary development and oogenesis and included lipases, Nanos, small heat shock proteins (sHsps) and histones; these were further verified by qRT-PCR and may play essential roles in M. separata reproduction. Collectively, our findings reveal underlying mechanisms of M.separata reproduction and may lead to RNAi-based management strategies targeting reproductive physiology.
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Contreras B, Adelman ZN, Chae K. Evaluating the Mating Competency of Genetically Modified Male Mosquitoes in Laboratory Conditions. FRONTIERS IN TROPICAL DISEASES 2023; 4:1106671. [PMID: 37860147 PMCID: PMC10586724 DOI: 10.3389/fitd.2023.1106671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023] Open
Abstract
Efforts to eradicate mosquito-borne diseases have increased the demand for genetic control strategies, many of which involve the release of genetically modified (GM) mosquito males into natural populations. The first hurdle for GM males is to compete with their wild-type counterparts for access to females. Here, we introduce an eye color-based mating assay, in which both Lvp wild-type and kynurenine 3-monooxygenase (kmo)-null males compete for access to kmo-null females, and therefore the eye color phenotype (black or white) of the progeny is dependent on the parental mating pair. A series of tests addressed that male mating competitiveness between the two strains can significantly be influenced by adult density, light intensity, and mating duration. Interestingly, the mating competitiveness of males was not correlated with body size, which was negatively influenced by a high larval density. Lastly, this eye color-associated assay was applied to characterize GM mosquitoes in their mating competitiveness, establishing this method as a fast and precise way of benchmarking this fitness parameter for laboratory-raised males.
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Affiliation(s)
- Bryan Contreras
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Zach N. Adelman
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Keun Chae
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
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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: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [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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36
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Terradas G, Bennett JB, Li Z, Marshall JM, Bier E. Genetic conversion of a split-drive into a full-drive element. Nat Commun 2023; 14:191. [PMID: 36635291 PMCID: PMC9837192 DOI: 10.1038/s41467-022-35044-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 11/16/2022] [Indexed: 01/13/2023] Open
Abstract
The core components of CRISPR-based gene drives, Cas9 and guide RNA (gRNA), either can be linked within a self-contained single cassette (full gene-drive, fGD) or be provided in two separate elements (split gene-drive, sGD), the latter offering greater control options. We previously engineered split systems that could be converted genetically into autonomous full drives. Here, we examine such dual systems inserted at the spo11 locus that are recoded to restore gene function and thus organismic fertility. Despite minimal differences in transmission efficiency of the sGD or fGD drive elements in single generation crosses, the reconstituted spo11 fGD cassette surprisingly exhibits slower initial drive kinetics than the unlinked sGD element in multigenerational cage studies, but then eventually catches up to achieve a similar level of final introduction. These unexpected kinetic behaviors most likely reflect differing transient fitness costs associated with individuals co-inheriting Cas9 and gRNA transgenes during the drive process.
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Affiliation(s)
- Gerard Terradas
- Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093, USA.,Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, 92093, USA.,Department of Entomology, The Center for Infectious Disease Dynamics, and the Huck Institutes for the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Jared B Bennett
- Biophysics Graduate Group, Division of Biological Sciences, College of Letters and Science, University of California, Berkeley, CA, 94720, USA
| | - Zhiqian Li
- Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093, USA.,Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, 92093, USA
| | - John M Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA, 94720, USA.,Innovative Genomics Institute, Berkeley, CA, 94720, USA
| | - Ethan Bier
- Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093, USA. .,Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, 92093, USA.
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37
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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] [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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38
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Bottino-Rojas V, James AA. Use of Insect Promoters in Genetic Engineering to Control Mosquito-Borne Diseases. Biomolecules 2022; 13:biom13010016. [PMID: 36671401 PMCID: PMC9855440 DOI: 10.3390/biom13010016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 12/16/2022] [Accepted: 12/18/2022] [Indexed: 12/24/2022] Open
Abstract
Mosquito transgenesis and gene-drive technologies provide the basis for developing promising new tools for vector-borne disease prevention by either suppressing wild mosquito populations or reducing their capacity from transmitting pathogens. Many studies of the regulatory DNA and promoters of genes with robust sex-, tissue- and stage-specific expression profiles have supported the development of new tools and strategies that could bring mosquito-borne diseases under control. Although the list of regulatory elements available is significant, only a limited set of those can reliably drive spatial-temporal expression. Here, we review the advances in our ability to express beneficial and other genes in mosquitoes, and highlight the information needed for the development of new mosquito-control and anti-disease strategies.
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Affiliation(s)
- Vanessa Bottino-Rojas
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697, USA
| | - Anthony A. James
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697, USA
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
- Correspondence:
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39
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Morianou I, Crisanti A, Nolan T, Hammond AM. CRISPR-Mediated Cassette Exchange (CriMCE): A Method to Introduce and Isolate Precise Marker-Less Edits. CRISPR J 2022; 5:868-876. [PMID: 36378258 DOI: 10.1089/crispr.2022.0026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The introduction of small unmarked edits to the genome of insects is essential to study the molecular underpinnings of important biological traits, such as resistance to insecticides and genetic control strategies. Advances in CRISPR genome engineering have made this possible, but prohibitively laborious for most laboratories due to low rates of editing and the lack of a selectable marker. To facilitate the generation and isolation of precise marker-less edits we have developed a two-step method based on CRISPR-mediated cassette exchange (CriMCE) of a marked placeholder for a variant of interest. This strategy can be used to introduce a wider range of potential edits compared with previous approaches while consolidating the workflow. We present proof-of-principle that CriMCE is a powerful tool by engineering three single nucleotide polymorphism variants into the genome of Anopheles gambiae, with 5-41 × higher rates of editing than homology-directed repair or prime editing.
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Affiliation(s)
- Ioanna Morianou
- Department of Life Sciences, Imperial College London, London, United Kingdom; S.r.l., Terni, Italy
| | - Andrea Crisanti
- Department of Life Sciences, Imperial College London, London, United Kingdom; S.r.l., Terni, Italy.,Department of Molecular Medicine, University of Padova, Padua, Italy; S.r.l., Terni, Italy
| | - Tony Nolan
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom; S.r.l., Terni, Italy
| | - Andrew M Hammond
- Department of Life Sciences, Imperial College London, London, United Kingdom; S.r.l., Terni, Italy.,Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA; and S.r.l., Terni, Italy.,Biocentis, S.r.l., Terni, Italy
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40
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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, MD.) 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] [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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41
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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] [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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42
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Chen C, Compton A, Nikolouli K, Wang A, Aryan A, Sharma A, Qi Y, Dellinger C, Hempel M, Potters M, Augustinos A, Severson DW, Bourtzis K, Tu Z. Marker-assisted mapping enables forward genetic analysis in Aedes aegypti, an arboviral vector with vast recombination deserts. Genetics 2022; 222:iyac140. [PMID: 36083009 PMCID: PMC9630976 DOI: 10.1093/genetics/iyac140] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 08/29/2022] [Indexed: 11/14/2022] Open
Abstract
Aedes aegypti is a major vector of arboviruses that cause dengue, chikungunya, yellow fever, and Zika. Although recent success in reverse genetics has facilitated rapid progress in basic and applied research, integration of forward genetics with modern technologies remains challenging in this important species, as up to 47% of its chromosome is refractory to genetic mapping due to extremely low rate of recombination. Here, we report the development of a marker-assisted mapping strategy to readily screen for and genotype only the rare but informative recombinants, drastically increasing both the resolution and signal-to-noise ratio. Using marker-assisted mapping, we mapped a transgene that was inserted in a >100-Mb recombination desert and a sex-linked spontaneous red-eye (re) mutation just outside the region. We subsequently determined, by CRISPR/Cas9-mediated knockout, that cardinal is the causal gene of re, which is the first forward genetic identification of a causal gene in Ae. aegypti. The identification of the causal gene of the sex-linked re mutation provides the molecular foundation for using gene editing to develop versatile and stable genetic sexing methods. To facilitate genome-wide forward genetics in Ae. aegypti, we generated and compiled a number of lines with markers throughout the genome. Thus, by overcoming the challenges presented by the vast recombination deserts and the scarcity of markers, we have shown that effective forward genetic analysis is increasingly feasible in this important arboviral vector species.
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Affiliation(s)
- Chujia Chen
- Genetics Bioinformatics and Computational Biology Program, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Austin Compton
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Katerina Nikolouli
- Insect Pest Control Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, IAEA Laboratories, 2444 Seibersdorf, Austria
| | - Aihua Wang
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Azadeh Aryan
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Atashi Sharma
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Yumin Qi
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Camden Dellinger
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Melanie Hempel
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Mark Potters
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Antonios Augustinos
- Insect Pest Control Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, IAEA Laboratories, 2444 Seibersdorf, Austria
| | - David W Severson
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Kostas Bourtzis
- Insect Pest Control Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, IAEA Laboratories, 2444 Seibersdorf, Austria
| | - Zhijian Tu
- Genetics Bioinformatics and Computational Biology Program, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
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43
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Huang W, Vega-Rodriguez J, Kizito C, Cha SJ, Jacobs-Lorena M. Combining transgenesis with paratransgenesis to fight malaria. eLife 2022; 11:e77584. [PMID: 36281969 PMCID: PMC9596157 DOI: 10.7554/elife.77584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 10/02/2022] [Indexed: 11/13/2022] Open
Abstract
Malaria is among the deadliest infectious diseases, and Plasmodium, the causative agent, needs to complete a complex development cycle in its vector mosquito for transmission to occur. Two promising strategies to curb transmission are transgenesis, consisting of genetically engineering mosquitoes to express antimalarial effector molecules, and paratransgenesis, consisting of introducing into the mosquito commensal bacteria engineered to express antimalarial effector molecules. Although both approaches restrict parasite development in the mosquito, it is not known how their effectiveness compares. Here we provide an in-depth assessment of transgenesis and paratransgenesis and evaluate the combination of the two approaches. Using the Q-system to drive gene expression, we engineered mosquitoes to produce and secrete two effectors - scorpine and the MP2 peptide - into the mosquito gut and salivary glands. We also engineered Serratia, a commensal bacterium capable of spreading through mosquito populations to secrete effectors into the mosquito gut. Whereas both mosquito-based and bacteria-based approaches strongly reduced the oocyst and sporozoite intensity, a substantially stronger reduction of Plasmodium falciparum development was achieved when transgenesis and paratransgenesis were combined. Most importantly, transmission of Plasmodium berghei from infected to naïve mice was maximally inhibited by the combination of the two approaches. Combining these two strategies promises to become a powerful approach to combat malaria.
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Affiliation(s)
- Wei Huang
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public HealthBaltimoreUnited States
| | - Joel Vega-Rodriguez
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthRockvilleUnited States
| | - Chritopher Kizito
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public HealthBaltimoreUnited States
| | - Sung-Jae Cha
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public HealthBaltimoreUnited States
| | - Marcelo Jacobs-Lorena
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public HealthBaltimoreUnited States
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44
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Blouin MS, Bollmann SR, Tennessen JA. PTC2 region genotypes counteract Biomphalaria glabrata population differences between M-line and BS90 in resistance to infection by Schistosoma mansoni. PeerJ 2022; 10:e13971. [PMID: 36117535 PMCID: PMC9480060 DOI: 10.7717/peerj.13971] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/09/2022] [Indexed: 01/19/2023] Open
Abstract
Background Biomphalaria glabrata is a snail intermediate host for Schistosoma mansoni, a trematode responsible for human schistosomiasis. BS90 is one of the most well studied strains of B. glabrata owing to its high resistance to infection by most strains of S. mansoni. An F2 mapping study from 1999 identified two RAPD markers that associated with what appeared to be single-locus, dominant resistance by the BS90 population relative to the susceptible M-line population. One marker cannot be mapped, but the other, OPM-04, maps to within 5 Mb of PTC2, a region we recently showed has a very large effect on resistance within another snail population challenged by the same strain of parasite (PR1). Here we tested the hypothesis that the PTC2 region contains the causal gene/s that explain the iconic resistance of BS90 snails. Methods We used marker-assisted backcrossing to drive the BS90 version of the PTC2 region (+/-~1 Mb on either side) into an M-line (susceptible strain) genetic background, and the M-line version into a BS90 genetic background. We challenged the offspring with PR1-strain schistosomes and tested for effects of allelic variation in the PTC2 region in a common genetic background. Results Relative to M-line haplotypes, the BS90 haplotype actually confers enhanced susceptibility. So we reject our original hypothesis. One possible explanation for our result was that the causal gene linked to OPM-04 is near, but not in the PTC2 block that we introgressed into each line. So we used an F2 cross to independently test the effects of the PTC2 and OPM-04 regions in a randomized genetic background. We confirmed that the BS90 haplotype confers increased susceptibility, and we see a similar, although non-significant effect at OPM-04. We discuss possible reasons why our results differed so dramatically from those of the 1999 study. We also present Pacbio assemblies of the PTC2 and flanking region in BS90 and M-line, compare with previously published PTC2 haplotypes, and discuss candidate genes that might be behind the enhanced susceptibility of the BS90 haplotype.
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Affiliation(s)
- Michael S. Blouin
- Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Stephanie R. Bollmann
- Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Jacob A. Tennessen
- Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
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45
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Melesse Vergara M, Labbé J, Tannous J. Reflection on the Challenges, Accomplishments, and New Frontiers of Gene Drives. BIODESIGN RESEARCH 2022; 2022:9853416. [PMID: 37850135 PMCID: PMC10521683 DOI: 10.34133/2022/9853416] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/19/2022] [Indexed: 10/19/2023] Open
Abstract
Ongoing pest and disease outbreaks pose a serious threat to human, crop, and animal lives, emphasizing the need for constant genetic discoveries that could serve as mitigation strategies. Gene drives are genetic engineering approaches discovered decades ago that may allow quick, super-Mendelian dissemination of genetic modifications in wild populations, offering hopes for medicine, agriculture, and ecology in combating diseases. Following its first discovery, several naturally occurring selfish genetic elements were identified and several gene drive mechanisms that could attain relatively high threshold population replacement have been proposed. This review provides a comprehensive overview of the recent advances in gene drive research with a particular emphasis on CRISPR-Cas gene drives, the technology that has revolutionized the process of genome engineering. Herein, we discuss the benefits and caveats of this technology and place it within the context of natural gene drives discovered to date and various synthetic drives engineered. Later, we elaborate on the strategies for designing synthetic drive systems to address resistance issues and prevent them from altering the entire wild populations. Lastly, we highlight the major applications of synthetic CRISPR-based gene drives in different living organisms, including plants, animals, and microorganisms.
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Affiliation(s)
| | - Jesse Labbé
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Invaio Sciences, Cambridge, MA 02138USA
| | - Joanna Tannous
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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46
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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: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [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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Leung S, Windbichler N, Wenger EA, Bever CA, Selvaraj P. Population replacement gene drive characteristics for malaria elimination in a range of seasonal transmission settings: a modelling study. Malar J 2022; 21:226. [PMID: 35883100 PMCID: PMC9327287 DOI: 10.1186/s12936-022-04242-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 07/11/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Gene drives are a genetic engineering method where a suite of genes is inherited at higher than Mendelian rates and has been proposed as a promising new vector control strategy to reinvigorate the fight against malaria in sub-Saharan Africa. METHODS Using an agent-based model of malaria transmission with vector genetics, the impacts of releasing population-replacement gene drive mosquitoes on malaria transmission are examined and the population replacement gene drive system parameters required to achieve local elimination within a spatially-resolved, seasonal Sahelian setting are quantified. The performance of two different gene drive systems-"classic" and "integral"-are evaluated. Various transmission regimes (low, moderate, and high-corresponding to annual entomological inoculation rates of 10, 30, and 80 infectious bites per person) and other simultaneous interventions, including deployment of insecticide-treated nets (ITNs) and passive healthcare-seeking, are also simulated. RESULTS Local elimination probabilities decreased with pre-existing population target site resistance frequency, increased with transmission-blocking effectiveness of the introduced antiparasitic gene and drive efficiency, and were context dependent with respect to fitness costs associated with the introduced gene. Of the four parameters, transmission-blocking effectiveness may be the most important to focus on for improvements to future gene drive strains because a single release of classic gene drive mosquitoes is likely to locally eliminate malaria in low to moderate transmission settings only when transmission-blocking effectiveness is very high (above ~ 80-90%). However, simultaneously deploying ITNs and releasing integral rather than classic gene drive mosquitoes significantly boosts elimination probabilities, such that elimination remains highly likely in low to moderate transmission regimes down to transmission-blocking effectiveness values as low as ~ 50% and in high transmission regimes with transmission-blocking effectiveness values above ~ 80-90%. CONCLUSION A single release of currently achievable population replacement gene drive mosquitoes, in combination with traditional forms of vector control, can likely locally eliminate malaria in low to moderate transmission regimes within the Sahel. In a high transmission regime, higher levels of transmission-blocking effectiveness than are currently available may be required.
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Affiliation(s)
- Shirley Leung
- Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Nikolai Windbichler
- Department of Life Sciences, Imperial College London, South Kensington, London, UK
| | - Edward A Wenger
- Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Caitlin A Bever
- Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Prashanth Selvaraj
- Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, WA, USA.
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Roy S, Juste SS, Sneider M, Auradkar A, Klanseck C, Li Z, Julio AHF, Lopez del Amo V, Bier E, Guichard A. Cas9/Nickase-induced allelic conversion by homologous chromosome-templated repair in Drosophila somatic cells. SCIENCE ADVANCES 2022; 8:eabo0721. [PMID: 35776792 PMCID: PMC10883370 DOI: 10.1126/sciadv.abo0721] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Repair of double-strand breaks (DSBs) in somatic cells is primarily accomplished by error-prone nonhomologous end joining and less frequently by precise homology-directed repair preferentially using the sister chromatid as a template. Here, a Drosophila system performs efficient somatic repair of both DSBs and single-strand breaks (SSBs) using intact sequences from the homologous chromosome in a process we refer to as homologous chromosome-templated repair (HTR). Unexpectedly, HTR-mediated allelic conversion at the white locus was more efficient (40 to 65%) in response to SSBs induced by Cas9-derived nickases D10A or H840A than to DSBs induced by fully active Cas9 (20 to 30%). Repair phenotypes elicited by Nickase versus Cas9 differ in both developmental timing (late versus early stages, respectively) and the production of undesired mutagenic events (rare versus frequent). Nickase-mediated HTR represents an efficient and unanticipated mechanism for allelic correction, with far-reaching potential applications in the field of gene editing.
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Affiliation(s)
- Sitara Roy
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Sara Sanz Juste
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Marketta Sneider
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Ankush Auradkar
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Carissa Klanseck
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Zhiqian Li
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Alison Henrique Ferreira Julio
- Instituto de Ciências Biomédicas (ICB), Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-902 RJ, Brazil
| | - Victor Lopez del Amo
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Ethan Bier
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
- Tata Institute for Genetics and Society-UCSD, La Jolla, CA 92093-0335, USA
| | - Annabel Guichard
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
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Chennuri PR, Adelman ZN, Myles KM. Genetic Approaches for Controlling CRISPR-based Autonomous Homing Gene Drives. Front Bioeng Biotechnol 2022; 10:897231. [PMID: 35782500 PMCID: PMC9240394 DOI: 10.3389/fbioe.2022.897231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/18/2022] [Indexed: 11/13/2022] Open
Abstract
CRISPR-based autonomous homing gene drives are a potentially transformative technology with the power to reduce the prevalence of, or even eliminate, vector-borne diseases, agricultural pests, and invasive species. However, there are a number of regulatory, ethical, environmental, and sociopolitical concerns surrounding the potential use of gene drives, particularly regarding the possibility for any unintended outcomes that might result from such a powerful technology. Therefore, there is an imminent need for countermeasures or technologies capable of exerting precise spatiotemporal control of gene drives, if their transformative potential is ever to be fully realized. This review summarizes the current state of the art in the development of technologies to prevent the uncontrolled spread of CRISPR-based autonomous homing gene drives.
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Filipović I, Rašić G, Hereward J, Gharuka M, Devine GJ, Furlong MJ, Etebari K. A high-quality de novo genome assembly based on nanopore sequencing of a wild-caught coconut rhinoceros beetle (Oryctes rhinoceros). BMC Genomics 2022; 23:426. [PMID: 35672676 PMCID: PMC9172067 DOI: 10.1186/s12864-022-08628-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 05/03/2022] [Indexed: 11/10/2022] Open
Abstract
Background An optimal starting point for relating genome function to organismal biology is a high-quality nuclear genome assembly, and long-read sequencing is revolutionizing the production of this genomic resource in insects. Despite this, nuclear genome assemblies have been under-represented for agricultural insect pests, particularly from the order Coleoptera. Here we present a de novo genome assembly and structural annotation for the coconut rhinoceros beetle, Oryctes rhinoceros (Coleoptera: Scarabaeidae), based on Oxford Nanopore Technologies (ONT) long-read data generated from a wild-caught female, as well as the assembly process that also led to the recovery of the complete circular genome assemblies of the beetle’s mitochondrial genome and that of the biocontrol agent, Oryctes rhinoceros nudivirus (OrNV). As an invasive pest of palm trees, O. rhinoceros is undergoing an expansion in its range across the Pacific Islands, requiring new approaches to management that may include strategies facilitated by genome assembly and annotation. Results High-quality DNA isolated from an adult female was used to create four ONT libraries that were sequenced using four MinION flow cells, producing a total of 27.2 Gb of high-quality long-read sequences. We employed an iterative assembly process and polishing with one lane of high-accuracy Illumina reads, obtaining a final size of the assembly of 377.36 Mb that had high contiguity (fragment N50 length = 12 Mb) and accuracy, as evidenced by the exceptionally high completeness of the benchmarked set of conserved single-copy orthologous genes (BUSCO completeness = 99.1%). These quality metrics place our assembly ahead of the published Coleopteran genomes, including that of an insect model, the red flour beetle (Tribolium castaneum). The structural annotation of the nuclear genome assembly contained a highly-accurate set of 16,371 protein-coding genes, with only 2.8% missing BUSCOs, and the expected number of non-coding RNAs. The number and structure of paralogous genes in a gene family like Sigma GST is lower than in another scarab beetle (Onthophagus taurus), but higher than in the red flour beetle (Tribolium castaneum), which suggests expansion of this GST class in Scarabaeidae. The quality of our gene models was also confirmed with the correct placement of O. rhinoceros among other members of the rhinoceros beetles (subfamily Dynastinae) in a phylogeny based on the sequences of 95 protein-coding genes in 373 beetle species from all major lineages of Coleoptera. Finally, we provide a list of 30 candidate dsRNA targets whose orthologs have been experimentally validated as highly effective targets for RNAi-based control of several beetles. Conclusions The genomic resources produced in this study form a foundation for further functional genetic research and management programs that may inform the control and surveillance of O. rhinoceros populations, and we demonstrate the efficacy of de novo genome assembly using long-read ONT data from a single field-caught insect. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08628-z.
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Affiliation(s)
- Igor Filipović
- School of Biological Sciences, The University of Queensland, St. Lucia, Australia. .,Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
| | - Gordana Rašić
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - James Hereward
- School of Biological Sciences, The University of Queensland, St. Lucia, Australia
| | - Maria Gharuka
- Research Division, Ministry of Agriculture and Livestock, Honiara, Solomon Islands
| | - Gregor J Devine
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Michael J Furlong
- School of Biological Sciences, The University of Queensland, St. Lucia, Australia
| | - Kayvan Etebari
- School of Biological Sciences, The University of Queensland, St. Lucia, Australia
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