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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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2
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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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3
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Li Z, You L, Hermann A, Bier E. Developmental progression of DNA double-strand break repair deciphered by a single-allele resolution mutation classifier. Nat Commun 2024; 15:2629. [PMID: 38521791 PMCID: PMC10960810 DOI: 10.1038/s41467-024-46479-2] [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: 11/13/2023] [Accepted: 02/27/2024] [Indexed: 03/25/2024] Open
Abstract
DNA double-strand breaks (DSBs) are repaired by a hierarchically regulated network of pathways. Factors influencing the choice of particular repair pathways, however remain poorly characterized. Here we develop an Integrated Classification Pipeline (ICP) to decompose and categorize CRISPR/Cas9 generated mutations on genomic target sites in complex multicellular insects. The ICP outputs graphic rank ordered classifications of mutant alleles to visualize discriminating DSB repair fingerprints generated from different target sites and alternative inheritance patterns of CRISPR components. We uncover highly reproducible lineage-specific mutation fingerprints in individual organisms and a developmental progression wherein Microhomology-Mediated End-Joining (MMEJ) or Insertion events predominate during early rapid mitotic cell cycles, switching to distinct subsets of Non-Homologous End-Joining (NHEJ) alleles, and then to Homology-Directed Repair (HDR)-based gene conversion. These repair signatures enable marker-free tracking of specific mutations in dynamic populations, including NHEJ and HDR events within the same samples, for in-depth analysis of diverse gene editing events.
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Affiliation(s)
- 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
| | - Lang You
- 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
| | - Anita Hermann
- 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
| | - 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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4
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Bai X, Yu K, Xiong S, Chen J, Yang Y, Ye X, Yao H, Wang F, Fang Q, Song Q, Ye G. CRISPR/Cas9-mediated mutagenesis of the white gene in an ectoparasitic wasp, Habrobracon hebetor. PEST MANAGEMENT SCIENCE 2024; 80:1219-1227. [PMID: 37899674 DOI: 10.1002/ps.7851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 09/25/2023] [Accepted: 10/30/2023] [Indexed: 10/31/2023]
Abstract
BACKGROUND The ectoparasitic wasp Habrobracon hebetor (Hymenoptera, Braconidae) can parasitize various species of lepidopteran pests. To maximize its potential for biological control, it is necessary to investigate its gene function through genome engineering. RESULTS To test the effectiveness of genome engineering system in H. hebetor, we injected the mixture of clustered regularly interspaced short palindromic repeats (CRISPR) -associated (Cas) 9 protein and single guide RNA(s) targeting gene white into embryos. The resulting mutants display a phenotype of eye pigment loss. The phenotype was caused by small indel and is heritable. Then, we compared some biological parameters between wildtype and mutant, and found there were no significant differences in other parameters except for the offspring female rate and adult longevity. In addition, cocoons could be used to extract genomic DNA for genotype during the gene editing process without causing unnecessary harm to H. hebetor. CONCLUSION Our results demonstrate that the CRISPR/Cas9 system can be used for H. hebetor genome editing and it does not adversely affect biological parameters of the parasitoid wasps. We also provide a feasible non-invasive genotype detection method using genomic DNA extracted from cocoons. Our study introduces a novel tool and method for studying gene function in H. hebetor, and may contribute to better application of H. hebetor in biocontrol. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Xue Bai
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Kaili Yu
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Shijiao Xiong
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Jin Chen
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Yi Yang
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Xinhai Ye
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Hongwei Yao
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Fang Wang
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Qi Fang
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Qisheng Song
- Division of Plant Science and Technology, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, MO, USA
| | - Gongyin Ye
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
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5
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D'Amato R, Taxiarchi C, Galardini M, Trusso A, Minuz RL, Grilli S, Somerville AGT, Shittu D, Khalil AS, Galizi R, Crisanti A, Simoni A, Müller R. Anti-CRISPR Anopheles mosquitoes inhibit gene drive spread under challenging behavioural conditions in large cages. Nat Commun 2024; 15:952. [PMID: 38296981 PMCID: PMC10830555 DOI: 10.1038/s41467-024-44907-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 01/10/2024] [Indexed: 02/02/2024] Open
Abstract
CRISPR-based gene drives have the potential to spread within populations and are considered as promising vector control tools. A doublesex-targeting gene drive was able to suppress laboratory Anopheles mosquito populations in small and large cages, and it is considered for field application. Challenges related to the field-use of gene drives and the evolving regulatory framework suggest that systems able to modulate or revert the action of gene drives, could be part of post-release risk-mitigation plans. In this study, we challenge an AcrIIA4-based anti-drive to inhibit gene drive spread in age-structured Anopheles gambiae population under complex feeding and behavioural conditions. A stochastic model predicts the experimentally-observed genotype dynamics in age-structured populations in medium-sized cages and highlights the necessity of large-sized cage trials. These experiments and experimental-modelling framework demonstrate the effectiveness of the anti-drive in different scenarios, providing further corroboration for its use in controlling the spread of gene drive in Anopheles.
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Affiliation(s)
- Rocco D'Amato
- Genetics and Ecology Research Centre, Polo of Genomics, Genetics and Biology (Polo GGB), Terni, Italy
| | | | - Marco Galardini
- Biological Design Center, Boston University, Boston, MA, USA
- Institute for Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, a joint venture between the Hannover Medical School (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School (MHH), Hannover, Germany
| | - Alessandro Trusso
- Genetics and Ecology Research Centre, Polo of Genomics, Genetics and Biology (Polo GGB), Terni, Italy
| | - Roxana L Minuz
- Genetics and Ecology Research Centre, Polo of Genomics, Genetics and Biology (Polo GGB), Terni, Italy
| | - Silvia Grilli
- Department of Life Sciences, Imperial College London, London, UK
| | | | - Dammy Shittu
- Department of Life Sciences, Imperial College London, London, UK
| | - Ahmad S Khalil
- Biological Design Center, Boston University, Boston, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Roberto Galizi
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Keele, UK
| | - Andrea Crisanti
- Department of Life Sciences, Imperial College London, London, UK
- Department of Molecular Medicine, University of Padova, Padua, Italy
| | - Alekos Simoni
- Genetics and Ecology Research Centre, Polo of Genomics, Genetics and Biology (Polo GGB), Terni, Italy.
- Department of Life Sciences, Imperial College London, London, UK.
| | - Ruth Müller
- Genetics and Ecology Research Centre, Polo of Genomics, Genetics and Biology (Polo GGB), Terni, Italy.
- Unit of Entomology, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
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6
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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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7
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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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8
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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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9
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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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10
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Hernández Elizárraga VH, Ballantyne S, O'Brien LG, Americo JA, Suhr ST, Senut MC, Minerich B, Merkes CM, Edwards TM, Klymus K, Richter CA, Waller DL, Passamaneck YJ, Rebelo MF, Gohl DM. Toward invasive mussel genetic biocontrol: Approaches, challenges, and perspectives. iScience 2023; 26:108027. [PMID: 37860763 PMCID: PMC10583111 DOI: 10.1016/j.isci.2023.108027] [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] [Indexed: 10/21/2023] Open
Abstract
Invasive freshwater mussels, such as the zebra (Dreissena polymorpha), quagga (Dreissena rostriformis bugensis), and golden (Limnoperna fortunei) mussel have spread outside their native ranges throughout many regions of the North American, South American, and European continents in recent decades, damaging infrastructure and the environment. This review describes ongoing efforts by multiple groups to develop genetic biocontrol methods for invasive mussels. First, we provide an overview of genetic biocontrol strategies that have been applied in other invasive or pest species. Next, we summarize physical and chemical methods that are currently in use for invasive mussel control. We then describe the multidisciplinary approaches our groups are employing to develop genetic biocontrol tools for invasive mussels. Finally, we discuss the challenges and limitations of applying genetic biocontrol tools to invasive mussels. Collectively, we aim to openly share information and combine expertise to develop practical tools to enable the management of invasive freshwater mussels.
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Affiliation(s)
| | - Scott Ballantyne
- Department of Biology, University of Wisconsin River Falls, River Falls, WI, USA
| | | | | | | | | | | | - Christopher M. Merkes
- U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, WI, USA
| | - Thea M. Edwards
- U.S. Geological Survey, Columbia Environmental Research Center, Columbia, MO, USA
| | - Katy Klymus
- U.S. Geological Survey, Columbia Environmental Research Center, Columbia, MO, USA
| | - Catherine A. Richter
- U.S. Geological Survey, Columbia Environmental Research Center, Columbia, MO, USA
| | - Diane L. Waller
- U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, WI, USA
| | - Yale J. Passamaneck
- Bureau of Reclamation, Technical Service Center, Hydraulic Investigations and Laboratory Services, Ecological Research Laboratory, Denver, CO, USA
| | - Mauro F. Rebelo
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Daryl M. Gohl
- University of Minnesota Genomics Center, Minneapolis, MN, USA
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
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11
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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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12
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Ning SF, Huo LX, Lv L, Wang Y, Zhang LS, Che WN, Dong H, Zhou JC. The identification and expression pattern of the sex determination genes and their sex-specific variants in the egg parasitoid Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae). Front Physiol 2023; 14:1243753. [PMID: 37693004 PMCID: PMC10485257 DOI: 10.3389/fphys.2023.1243753] [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: 06/21/2023] [Accepted: 08/10/2023] [Indexed: 09/12/2023] Open
Abstract
Introduction: Trichogramma wasps are egg parasitoids of agricultural lepidopteran pests. The sex of Trichogramma is determined by its ploidy as well as certain sex ratio distorters, such as the endosymbiotic bacteria Wolbachia spp. and the paternal sex ratio (PSR) chromosome. The sex determination systems of hymenopterans, such as Trichogramma spp., involve cascades of the genes transformer (tra), transformer-2 (tra2), and doublesex (dsx) and are associated with sex-specific tra and dsx splicing. First, these genes and their sex-specific variants must be identified to elucidate the interactions between the sex ratio disorders and the sex determination mechanism of Trichogramma. Methods: Here, we characterized the sex determination genes tra, tra2, and dsx in Trichogramma dendrolimi. Sex-specific tra and dsx variants were detected in cDNA samples obtained from both male and female Trichogramma wasps. They were observed in the early embryos (1-10 h), late embryos (12-20 h), larvae (32 h and 48 h), pre-pupae (96 h), and pupae (144 h, 168 h, 192 h, and 216 h) of both male and female T. dendrolimi offspring. Results: We detected female-specific tra variants throughout the entire early female offspring stage. The male-specific variant began to express at 9-10 h as the egg was not fertilized. However, we did not find any maternally derived, female-specific tra variant in the early male embryo. This observation suggests that the female-specific tra variant expressed in the female embryo at 1-9 h may not have originated from the maternal female wasp. Discussion: The present study might be the first to identify the sex determination genes and sex-specific gene splicing in Trichogramma wasps. The findings of this study lay the foundation for investigating the sex determination mechanisms of Trichogramma and other wasps. They also facilitate sex identification in immature T. dendrolimi and the application of this important egg parasitoid in biological insect pest control programs.
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Affiliation(s)
- Su-Fang Ning
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Liang-Xiao Huo
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Lin Lv
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Ying Wang
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Li-Sheng Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Wu-Nan Che
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Hui Dong
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Jin-Cheng Zhou
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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13
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Wang C, Wang J, Lu J, Xiong Y, Zhao Z, Yu X, Zheng X, Li J, Lin Q, Ren Y, Hu Y, He X, Li C, Zeng Y, Miao R, Guo M, Zhang B, Zhu Y, Zhang Y, Tang W, Wang Y, Hao B, Wang Q, Cheng S, He X, Yao B, Gao J, Zhu X, Yu H, Wang Y, Sun Y, Zhou C, Dong H, Ma X, Guo X, Liu X, Tian Y, Liu S, Wang C, Cheng Z, Jiang L, Zhou J, Guo H, Jiang L, Tao D, Chai J, Zhang W, Wang H, Wu C, Wan J. A natural gene drive system confers reproductive isolation in rice. Cell 2023; 186:3577-3592.e18. [PMID: 37499659 DOI: 10.1016/j.cell.2023.06.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 02/02/2023] [Accepted: 06/28/2023] [Indexed: 07/29/2023]
Abstract
Hybrid sterility restricts the utilization of superior heterosis of indica-japonica inter-subspecific hybrids. In this study, we report the identification of RHS12, a major locus controlling male gamete sterility in indica-japonica hybrid rice. We show that RHS12 consists of two genes (iORF3/DUYAO and iORF4/JIEYAO) that confer preferential transmission of the RHS12-i type male gamete into the progeny, thereby forming a natural gene drive. DUYAO encodes a mitochondrion-targeted protein that interacts with OsCOX11 to trigger cytotoxicity and cell death, whereas JIEYAO encodes a protein that reroutes DUYAO to the autophagosome for degradation via direct physical interaction, thereby detoxifying DUYAO. Evolutionary trajectory analysis reveals that this system likely formed de novo in the AA genome Oryza clade and contributed to reproductive isolation (RI) between different lineages of rice. Our combined results provide mechanistic insights into the genetic basis of RI as well as insights for strategic designs of hybrid rice breeding.
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Affiliation(s)
- Chaolong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jian Wang
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jiayu Lu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yehui Xiong
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhigang Zhao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaowen Yu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaoming Zheng
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jing Li
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Qibing Lin
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yulong Ren
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yang Hu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaodong He
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chao Li
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yonglun Zeng
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Rong Miao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Mali Guo
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Bosen Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ying Zhu
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Yunhui Zhang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Weijie Tang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yunlong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Benyuan Hao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Qiming Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Siqi Cheng
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaojuan He
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Bowen Yao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Junwen Gao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xufei Zhu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Hao Yu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yong Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yan Sun
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chunlei Zhou
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Hui Dong
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaoding Ma
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiuping Guo
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xi Liu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yunlu Tian
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Shijia Liu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Chunming Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhijun Cheng
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Ling Jiang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Jiawu Zhou
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Huishan Guo
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Liwen Jiang
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Dayun Tao
- Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China
| | - Jijie Chai
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Wei Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Haiyang Wang
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Chuanyin Wu
- State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Jianmin Wan
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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14
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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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15
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Kou Z, Luo X, Jiang Y, Chen B, Song Y, Wang Y, Xu J, Tomberlin JK, Huang Y. Establishment of highly efficient transgenic system for black soldier fly (Hermetia illucens). INSECT SCIENCE 2023; 30:888-900. [PMID: 36624657 DOI: 10.1111/1744-7917.13147] [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: 09/04/2022] [Revised: 10/21/2022] [Accepted: 11/07/2022] [Indexed: 06/17/2023]
Abstract
The black soldier fly (BSF), Hermetia illucens, is a promising insect for mitigating solid waste problems as its larvae are able to bioconvert organic waste into valuable biomass. We recently reported a high-quality genome assembly of the BSF; analysis of this genome sequence will further the understanding of insect biology and identify genes that can be manipulated to improve efficiency of bioconversion. To enable genetic manipulation of the BSF, we have established the first transgenic methods for this economically important insect. We cloned and identified the ubiquitous actin5C promoter (Hiactin5C-p3k) and 3 endogenous U6 promoters (HiU6:1, HiU6:2, and HiU6:3). The Hiactin5C promoter was used to drive expression of a hyperactive variant of the piggyBac transposase, which exhibited up to 6-fold improvement in transformation rate when compared to the wild-type transposase. Furthermore, we evaluated the 3 HiU6 promoters using this transgenic system. HiU6:1 and HiU6:2 promoters provided the highest knockdown efficiency with RNAi and are thus promising candidates for future Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) development. Overall, our findings provide valuable genetic engineering toolkits for basic research and genetic manipulation of the BSF.
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Affiliation(s)
- Zongqing Kou
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xingyu Luo
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yuguo Jiang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bihui Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yu Song
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yaohui Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Jun Xu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | | | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
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16
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Smidler AL, Pai JJ, Apte RA, Sánchez C. HM, Corder RM, Jeffrey Gutiérrez E, Thakre N, Antoshechkin I, Marshall JM, Akbari OS. A confinable female-lethal population suppression system in the malaria vector, Anopheles gambiae. SCIENCE ADVANCES 2023; 9:eade8903. [PMID: 37406109 PMCID: PMC10321730 DOI: 10.1126/sciadv.ade8903] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 06/01/2023] [Indexed: 07/07/2023]
Abstract
Malaria is among the world's deadliest diseases, predominantly affecting Sub-Saharan Africa and killing over half a million people annually. Controlling the principal vector, the mosquito Anopheles gambiae, as well as other anophelines, is among the most effective methods to control disease spread. Here, we develop a genetic population suppression system termed Ifegenia (inherited female elimination by genetically encoded nucleases to interrupt alleles) in this deadly vector. In this bicomponent CRISPR-based approach, we disrupt a female-essential gene, femaleless (fle), demonstrating complete genetic sexing via heritable daughter gynecide. Moreover, we demonstrate that Ifegenia males remain reproductively viable and can load both fle mutations and CRISPR machinery to induce fle mutations in subsequent generations, resulting in sustained population suppression. Through modeling, we demonstrate that iterative releases of nonbiting Ifegenia males can act as an effective, confinable, controllable, and safe population suppression and elimination system.
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Affiliation(s)
- Andrea L. Smidler
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - James J. Pai
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Reema A. Apte
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Héctor M. Sánchez C.
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA 94720, USA
| | - Rodrigo M. Corder
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA 94720, USA
| | - Eileen Jeffrey Gutiérrez
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA 94720, USA
- Oxitec Ltd., Abingdon, OX14 4RQ, UK
| | - Neha Thakre
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Igor Antoshechkin
- Division of Biology and Biological Engineering (BBE), California Institute of Technology, Pasadena, CA 91125, USA
| | - John M. Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA 94720, USA
- Innovative Genomics Institute, University of California, Berkeley, CA 94720, 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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17
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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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18
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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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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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20
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Li J, Champer J. Harnessing Wolbachia cytoplasmic incompatibility alleles for confined gene drive: A modeling study. PLoS Genet 2023; 19:e1010591. [PMID: 36689491 PMCID: PMC9894560 DOI: 10.1371/journal.pgen.1010591] [Citation(s) in RCA: 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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21
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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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22
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Chen H, Sun H, Xie J, Yao Z, Zheng W, Li Z, Deng Z, Li X, Zhang H. CRISPR/Cas9-induced Mutation of Sex Peptide Receptor Gene Bdspr Affects Ovary, Egg Laying, and Female Fecundity in Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). JOURNAL OF INSECT SCIENCE (ONLINE) 2023; 23:2. [PMID: 36640045 PMCID: PMC9840094 DOI: 10.1093/jisesa/ieac078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Indexed: 06/17/2023]
Abstract
The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is an invasive and polyphagous pest of horticultural crops, and it can cause huge economic losses in agricultural production. The rapid development of CRISPR/Cas9 gene editing technology has provided new opportunities for the scientific control of agricultural pests. Here, we explore the applicability of the B. dorsalis sex peptide receptor (Bdspr) as a target gene for the CRISPR/Cas9-based sterile insect technique (SIT) in B. dorsalis. We screened two high-efficient single guide RNAs (sgRNAs) for gene editing. The results showed that both mutation efficiency and germline transmission rate were 100% in the surviving G0 females (8/8) from injected embryos, and that 75% of mosaically mutated G0 females (6/8) were sterile. The 50% of heterozygous G1 females (4/8) could not lay eggs; 100% of eggs laid by them could not survive; and 62.5% of individual females (5/8) had abnormal ovaries. These results indicate that Bdspr plays an important role in regulating fertility, egg viability, and ovary development in female B. dorsalis, suggesting that the spr gene can be used for CRISPR/Cas9-based SIT in B. dorsalis.
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Affiliation(s)
| | | | - Junfei Xie
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Zhichao Yao
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Wenping Zheng
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Ziniu Li
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Zhurong Deng
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Xiaoxue Li
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
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23
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Geci R, Willis K, Burt A. Gene drive designs for efficient and localisable population suppression using Y-linked editors. PLoS Genet 2022; 18:e1010550. [PMID: 36574454 PMCID: PMC9829173 DOI: 10.1371/journal.pgen.1010550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 01/09/2023] [Accepted: 11/29/2022] [Indexed: 12/28/2022] Open
Abstract
The sterile insect technique (SIT) has been successful in controlling some pest species but is not practicable for many others due to the large number of individuals that need to be reared and released. Previous computer modelling has demonstrated that the release of males carrying a Y-linked editor that kills or sterilises female descendants could be orders of magnitude more efficient than SIT while still remaining spatially restricted, particularly if combined with an autosomal sex distorter. In principle, further gains in efficiency could be achieved by using a self-propagating double drive design, in which each of the two components (the Y-linked editor and the sex ratio distorter) boosted the transmission of the other. To better understand the expected dynamics and impact of releasing constructs of this new design we have analysed a deterministic population genetic and population dynamic model. Our modelling demonstrates that this design can suppress a population from very low release rates, with no invasion threshold. Importantly, the design can work even if homing rates are low and sex chromosomes are silenced at meiosis, potentially expanding the range of species amenable to such control. Moreover, the predicted dynamics and impacts can be exquisitely sensitive to relatively small (e.g., 25%) changes in allele frequencies in the target population, which could be exploited for sequence-based population targeting. Analysis of published Anopheles gambiae genome sequences indicates that even for weakly differentiated populations with an FST of 0.02 there may be thousands of suitably differentiated genomic sites that could be used to restrict the spread and impact of a release. Our proposed design, which extends an already promising development pathway based on Y-linked editors, is therefore a potentially useful addition to the menu of options for genetic biocontrol.
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Affiliation(s)
- René Geci
- Dept. of Life Sciences, Imperial College London, Silwood Park, United Kingdom
| | - Katie Willis
- Dept. of Life Sciences, Imperial College London, Silwood Park, United Kingdom
| | - Austin Burt
- Dept. of Life Sciences, Imperial College London, Silwood Park, United Kingdom
- * E-mail:
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24
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Resnik DB, Medina RF, Gould F, Church G, Kuzma J. Genes drive organisms and slippery slopes. Pathog Glob Health 2022:1-10. [PMID: 36562087 DOI: 10.1080/20477724.2022.2160895] [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: 12/24/2022] Open
Abstract
The bioethical debate about using gene drives to alter or eradicate wild populations has focused mostly on issues concerning short-term risk assessment and management, governance and oversight, and public and community engagement, but has not examined big-picture- 'where is this going?'-questions in great depth. In other areas of bioethical controversy, big-picture questions often enter the public forum via slippery slope arguments. Given the incredible potential of gene drive organisms to alter the Earth's biota, it is somewhat surprising that slippery slope arguments have not played a more prominent role in ethical and policy debates about these emerging technologies. In this article, we examine a type of slippery slope argument against using gene drives to alter or suppress wild pest populations and consider whether it has a role to play in ethical and policy debates. Although we conclude that this argument does not provide compelling reasons for banning the use of gene drives in wild pest populations, we believe that it still has value as a morally instructive cautionary narrative that can motivate scientists, ethicists, and members of the public to think more clearly about appropriate vs. inappropriate uses of gene drive technologies, the long-term and cumulative and emergent risks of using gene drives in wild populations, and steps that can be taken to manage these risks, such as protecting wilderness areas where people can enjoy life forms that have not been genetically engineered.
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Affiliation(s)
- David B Resnik
- National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Raul F Medina
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Fred Gould
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, USA
| | - George Church
- Wyss Institute for Biologically Inspired Engineering, Harvard Medical School, Boston, MA, USA
| | - Jennifer Kuzma
- School of Public and International Affairs, North Carolina State University, Raleigh, NC, USA
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25
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CRISPR/Cas9-Mediated Mutagenesis of Sex-Specific Doublesex Splicing Variants Leads to Sterility in Spodoptera frugiperda, a Global Invasive Pest. Cells 2022; 11:cells11223557. [PMID: 36428986 PMCID: PMC9688123 DOI: 10.3390/cells11223557] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/06/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022] Open
Abstract
Spodoptera frugiperda (J. E. Smith), an emerging invasive pest worldwide, has posed a serious agricultural threat to the newly invaded areas. Although somatic sex differentiation is fundamentally conserved among insects, the sex determination cascade in S. frugiperda is largely unknown. In this study, we cloned and functionally characterized Doublesex (dsx), a "molecular switch" modulating sexual dimorphism in S. frugiperda using male- and female-specific isoforms. Given that Lepidoptera is recalcitrant to RNAi, CRISPR/Cas9-mediated mutagenesis was employed to construct S. frugiperda mutants. Specifically, we designed target sites on exons 2, 4, and 5 to eliminate the common, female-specific, and male-specific regions of S. frugiperda dsx (Sfdsx), respectively. As expected, abnormal development of both the external and internal genitalia was observed during the pupal and adult stages. Interestingly, knocking out sex-specific dsx variants in S. frugiperda led to significantly reduced fecundity and fertility in adults of corresponding sex. Our combined results not only confirm the conserved function of dsx in S. frugiperda sex differentiation but also provide empirical evidence for dsx as a potential target for the Sterile Insect Technique (SIT) to combat this globally invasive pest in a sustainable and environmentally friendly way.
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26
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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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27
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Kojin BB, Compton A, Adelman ZN, Tu Z. Selective targeting of biting females to control mosquito-borne infectious diseases. Trends Parasitol 2022; 38:791-804. [PMID: 35952630 PMCID: PMC9372635 DOI: 10.1016/j.pt.2022.05.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/20/2022] [Accepted: 05/23/2022] [Indexed: 10/18/2022]
Abstract
Mosquitoes are vectors for a number of infectious diseases. Only females feed on blood to provision for their embryos and, in doing so, transmit pathogens to the associated vertebrate hosts. Therefore, sex is an important phenotype in the context of genetic control programs, both for sex separation in the rearing facilities to avoid releasing biting females and for ways to distort the sex ratio towards nonbiting males. We review recent progress in the fundamental knowledge of sex determination and sex chromosomes in mosquitoes and discuss new methods to achieve sex separation and sex ratio distortion to help control mosquito-borne infectious diseases. We conclude by suggesting a few critical areas for future research.
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Affiliation(s)
- Bianca B Kojin
- Department of Entomology and Agrilife Research, Texas A&M University, College Station, TX, USA
| | - Austin Compton
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA; Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Zach N Adelman
- Department of Entomology and Agrilife Research, Texas A&M University, College Station, TX, USA.
| | - Zhijian Tu
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA; Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA.
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28
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Belavilas-Trovas A, Gregoriou ME, Tastsoglou S, Soukia O, Giakountis A, Mathiopoulos K. A species-specific lncRNA modulates the reproductive ability of the asian tiger mosquito. Front Bioeng Biotechnol 2022; 10:885767. [PMID: 36091452 PMCID: PMC9448860 DOI: 10.3389/fbioe.2022.885767] [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: 02/28/2022] [Accepted: 07/11/2022] [Indexed: 11/21/2022] Open
Abstract
Long non-coding RNA (lncRNA) research has emerged as an independent scientific field in recent years. Despite their association with critical cellular and metabolic processes in plenty of organisms, lncRNAs are still a largely unexplored area in mosquito research. We propose that they could serve as exceptional tools for pest management due to unique features they possess. These include low inter-species sequence conservation and high tissue specificity. In the present study, we investigated the role of ovary-specific lncRNAs in the reproductive ability of the Asian tiger mosquito, Aedes albopictus. Through the analysis of transcriptomic data, we identified several lncRNAs that were differentially expressed upon blood feeding; we called these genes Norma (NOn-coding RNA in Mosquito ovAries). We observed that silencing some of these Normas resulted in significant impact on mosquito fecundity and fertility. We further focused on Norma3 whose silencing resulted in 43% oviposition reduction, in smaller ovaries and 53% hatching reduction of the laid eggs, compared to anti-GFP controls. Moreover, a significant downregulation of 2 mucins withing a neighboring (∼100 Kb) mucin cluster was observed in smaller anti-Norma3 ovaries, indicating a potential mechanism of in-cis regulation between Norma3 and the mucins. Our work constitutes the first experimental proof-of-evidence connecting lncRNAs with mosquito reproduction and opens a novel path for pest management.
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Affiliation(s)
- Alexandros Belavilas-Trovas
- Laboratory of Molecular Biology and Genomics, Department of Biochemistry & Biotechnology, University of Thessaly, Larissa, Greece
| | - Maria-Eleni Gregoriou
- Laboratory of Molecular Biology and Genomics, Department of Biochemistry & Biotechnology, University of Thessaly, Larissa, Greece
| | - Spyros Tastsoglou
- DIANA-Lab, Department of Computer Science and Biomedical Informatics, University of Thessaly, Lamia, Greece
- Hellenic Pasteur Institute, Athens, Greece
| | - Olga Soukia
- Laboratory of Molecular Biology and Genomics, Department of Biochemistry & Biotechnology, University of Thessaly, Larissa, Greece
| | - Antonis Giakountis
- Laboratory of Molecular Biology and Genomics, Department of Biochemistry & Biotechnology, University of Thessaly, Larissa, Greece
| | - Kostas Mathiopoulos
- Laboratory of Molecular Biology and Genomics, Department of Biochemistry & Biotechnology, University of Thessaly, Larissa, Greece
- *Correspondence: Kostas Mathiopoulos,
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29
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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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30
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Finney M, Romanowski J, Adelman ZN. Strategies to improve homology-based repair outcomes following CRISPR-based gene editing in mosquitoes: lessons in how to keep any repair disruptions local. Virol J 2022; 19:128. [PMID: 35908059 PMCID: PMC9338592 DOI: 10.1186/s12985-022-01859-2] [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: 02/22/2022] [Accepted: 07/18/2022] [Indexed: 11/10/2022] Open
Abstract
Programmable gene editing systems such as CRISPR-Cas have made mosquito genome engineering more practical and accessible, catalyzing the development of cutting-edge genetic methods of disease vector control. This progress, however, has been limited by the low efficiency of homology-directed repair (HDR)-based sequence integration at DNA double-strand breaks (DSBs) and a lack of understanding about DSB repair in mosquitoes. Innovative efforts to optimize HDR sequence integration by inhibiting non-homologous end joining or promoting HDR have been performed in mammalian systems, however many of these approaches have not been applied to mosquitoes. Here, we review some of the most relevant steps of DNA DSB repair choice and highlight promising approaches that influence this choice to enhance HDR in the context of mosquito gene editing.
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Affiliation(s)
- Micaela Finney
- Department of Entomology, Texas A&M University, 329A Minnie Belle Heep Center, 370 Olsen Blvd, College Station, TX, 77843, USA
| | - Joseph Romanowski
- Department of Entomology, Texas A&M University, 329A Minnie Belle Heep Center, 370 Olsen Blvd, College Station, TX, 77843, USA
| | - Zach N Adelman
- Department of Entomology, Texas A&M University, 329A Minnie Belle Heep Center, 370 Olsen Blvd, College Station, TX, 77843, 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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Abstract
Insects have evolved highly diverse genetic sex-determination mechanisms and a relatively balanced male to female sex ratio is generally expected. However, selection may shift the optimal sex ratio while meiotic drive and endosymbiont manipulation can result in sex ratio distortion (SRD). Recent advances in sex chromosome genomics and CRISPR/Cas9-mediated genome editing brought significant insights into the molecular regulators of sex determination in an increasing number of insects and provided new ways to engineer SRD. We review these advances and discuss both naturally occurring and engineered SRD in the context of the Anthropocene. We emphasize SRD-mediated biological control of insects to help improve One Health, sustain agriculture, and conserve endangered species.
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Affiliation(s)
- Austin Compton
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Zhijian Tu
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
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Brozak SJ, Mohammed-Awel J, Gumel AB. Mathematics of a single-locus model for assessing the impacts of pyrethroid resistance and temperature on population abundance of malaria mosquitoes. Infect Dis Model 2022; 7:277-316. [PMID: 35782338 PMCID: PMC9234087 DOI: 10.1016/j.idm.2022.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/25/2022] [Accepted: 05/25/2022] [Indexed: 11/18/2022] Open
Abstract
This study presents a genetic-ecology modeling framework for assessing the combined impacts of insecticide resistance, temperature variability, and insecticide-based interventions on the population abundance and control of malaria mosquitoes by genotype. Rigorous analyses of the model we developed reveal that the boundary equilibrium with only mosquitoes of homozygous sensitive (resistant) genotype is locally-asymptotically stable whenever a certain ecological threshold, denoted by R0SS(R0RR), is less than one. Furthermore, genotype i drives genotype j to extinction whenever R0j>1 and R0i<1 (where i, j = SS or RR, with i ≠ j). The model exhibits the phenomenon of bistability when both thresholds are less than one. In such a bistable situation, convergence to any of the two boundary equilibria depends on the initial allele distribution in the state variables of the model. Furthermore, in this bistable case, where max{R0SS,R0RR}<1, the basin of attraction of the boundary equilibrium of the mosquito genotype with lower value of the ecological threshold is larger. Specifically, the basin of attraction of the boundary equilibrium for genotype i is larger than that of genotype j if R0i<R0j<1. When both ecological thresholds exceed one (min{R0SS,R0RR}>1), the two boundary equilibria lose their stability, and a coexistence equilibrium (where all three mosquito genotypes coexist) becomes locally-asymptotically stable. Global sensitivity analysis shows that the key parameters that greatly influence the dynamics and population abundance of resistant mosquitoes include the proportion of new adult mosquitoes that are females, the insecticide-induced mortality rate of adult female mosquitoes, the coverage level and efficacy of adulticides used in the community, the oviposition rates for eggs of heterozygous and homozygous resistant genotypes, and the modification parameter accounting for the reduction in insecticide-induced mortality due to resistance. Numerical simulations show that the adult mosquito population increases with increasing temperature until a peak is reached at 31 °C, and declines thereafter. Simulating the model for moderate and high adulticide coverage, together with varying fitness costs of resistance, shows a switch in the dominant genotype at equilibrium as temperature is varied. In other words, this study shows that, for certain combinations of adulticide coverage and fitness costs of insecticide resistance, increases in temperature could result in effective management of resistance (by causing the switch from a stable resistant-only boundary equilibrium (at 18 °C) to a stable sensitive-only boundary equilibrium (at 25 °C)). Finally, this study shows that, for moderate fitness costs of resistance, density-dependent larval mortality suppresses the total population of adult mosquitoes with the resistant allele for all temperature values in the range [18 °C–36 °C].
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Affiliation(s)
- Samantha J. Brozak
- School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Jemal Mohammed-Awel
- Department of Mathematics, Morgan State University, Baltimore, MD, 21251, USA
| | - Abba B. Gumel
- School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, 85287, USA
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
- Department of Mathematics and Applied Mathematics, University of Pretoria, Pretoria, 0002, South Africa
- Corresponding author. School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, 85287, USA.
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A nickase Cas9 gene-drive system promotes super-Mendelian inheritance in Drosophila. Cell Rep 2022; 39:110843. [PMID: 35613590 PMCID: PMC9190248 DOI: 10.1016/j.celrep.2022.110843] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/07/2022] [Accepted: 04/28/2022] [Indexed: 01/01/2023] Open
Abstract
CRISPR-based gene-drives have been proposed for managing insect populations, including disease-transmitting mosquitoes, due to their ability to bias their inheritance toward super-Mendelian rates (>50%). Current technologies use a Cas9 that introduces DNA double-strand breaks into the opposing wild-type allele to replace it with a copy of the gene-drive allele via DNA homology-directed repair. However, the use of different Cas9 versions is unexplored, and alternative approaches could increase the available toolkit for gene-drive designs. Here, we report a gene-drive that relies on Cas9 nickases that generate staggered paired nicks in DNA to propagate the engineered gene-drive cassette. We show that generating 5′ overhangs in the system yields efficient allelic conversion. The nickase gene-drive arrangement produces large, stereotyped deletions that are advantageous to eliminate viable animals carrying small mutations when targeting essential genes. Our nickase approach should expand the repertoire for gene-drive arrangements aimed at applications in mosquitoes and beyond. Gene-drives using wild-type Cas9 offer solutions to fight vector-borne diseases, yet alternative strategies are needed to increase the available toolkit. López Del Amo et al. describe a nickase-based gene-drive system that promotes super-Mendelian inheritance of an engineered cassette in the Drosophila germ line, providing alternative designs for CRISPR-based gene-drive.
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Metzloff M, Yang E, Dhole S, Clark AG, Messer PW, Champer J. Experimental demonstration of tethered gene drive systems for confined population modification or suppression. BMC Biol 2022; 20:119. [PMID: 35606745 PMCID: PMC9128227 DOI: 10.1186/s12915-022-01292-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 04/11/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Homing gene drives hold great promise for the genetic control of natural populations. However, current homing systems are capable of spreading uncontrollably between populations connected by even marginal levels of migration. This could represent a substantial sociopolitical barrier to the testing or deployment of such drives and may generally be undesirable when the objective is only local population control, such as suppression of an invasive species outside of its native range. Tethered drive systems, in which a locally confined gene drive provides the CRISPR nuclease needed for a homing drive, could provide a solution to this problem, offering the power of a homing drive and confinement of the supporting drive. RESULTS Here, we demonstrate the engineering of a tethered drive system in Drosophila, using a regionally confined CRISPR Toxin-Antidote Recessive Embryo (TARE) drive to support modification and suppression homing drives. Each drive was able to bias inheritance in its favor, and the TARE drive was shown to spread only when released above a threshold frequency in experimental cage populations. After the TARE drive had established in the population, it facilitated the spread of a subsequently released split homing modification drive (to all individuals in the cage) and of a homing suppression drive (to its equilibrium frequency). CONCLUSIONS Our results show that the tethered drive strategy is a viable and easily engineered option for providing confinement of homing drives to target populations.
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Affiliation(s)
- Matthew Metzloff
- Department of Computational Biology, Cornell University, Ithaca, NY, 14853, USA
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Emily Yang
- Department of Computational Biology, Cornell University, Ithaca, NY, 14853, USA
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Sumit Dhole
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, 27695, USA
| | - Andrew G Clark
- Department of Computational Biology, Cornell University, Ithaca, NY, 14853, USA
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Philipp W Messer
- Department of Computational Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Jackson Champer
- Department of Computational Biology, Cornell University, Ithaca, NY, 14853, USA.
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA.
- Present Address: Center for Bioinformatics, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.
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Nash A, Capriotti P, Hoermann A, Papathanos PA, Windbichler N. Intronic gRNAs for the Construction of Minimal Gene Drive Systems. Front Bioeng Biotechnol 2022; 10:857460. [PMID: 35646834 PMCID: PMC9133698 DOI: 10.3389/fbioe.2022.857460] [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: 01/18/2022] [Accepted: 03/24/2022] [Indexed: 11/17/2022] Open
Abstract
Gene drives are promising tools for the genetic control of insect vector or pest populations. CRISPR-based gene drives are generally highly complex synthetic constructs consisting of multiple transgenes and their respective regulatory elements. This complicates the generation of new gene drives and the testing of the behavior of their constituent functional modules. Here, we explored the minimal genetic components needed to constitute autonomous gene drives in Drosophila melanogaster. We first designed intronic gRNAs that can be located directly within coding transgene sequences and tested their functions in cell lines. We then integrated a Cas9 open reading frame hosting such an intronic gRNA within the Drosophila rcd-1r locus that drives the expression in the male and female germlines. We showed that upon removal of the fluorescent transformation marker, the rcd-1rd allele supports efficient gene drive. We assessed the propensity of this driver, designed to be neutral with regards to fitness and host gene function, to propagate in caged fly populations. Because of their simplicity, such integral gene drives could enable the modularization of drive and effector functions. We also discussed the possible biosafety implications of minimal and possibly recoded gene drives.
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Affiliation(s)
- Alexander Nash
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Paolo Capriotti
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Astrid Hoermann
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Phillipos Aris Papathanos
- Department of Entomology, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel
| | - Nikolai Windbichler
- Department of Life Sciences, Imperial College London, London, United Kingdom
- *Correspondence: Nikolai Windbichler,
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Ditter RE, Campos M, Pinto J, Cornel AJ, Rompão H, Lanzaro GC. Mitogenome Analyses Reveal Limited Introduction of Anopheles coluzzii Into the Central African Islands of São Tomé and Príncipe. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.855272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Islands possess physical characteristics that make them uniquely well-suited for initial field trials of new genetic-based technologies applied to African malaria vectors. This has led to efforts to characterize the degree of isolation of island mosquito populations. São Tomé and Príncipe (STP) is a country composed of two small islands in the Gulf of Guinea (Central Africa) where Anopheles coluzzii is the primary malaria vector. Several studies have shown a relatively high degree of genetic isolation between A. coluzzii populations in STP and the mainland compared with pairs of mainland populations separated by equivalent distances. Here, we analyzed complete mitochondrial genomes of individual A. coluzzii specimens from STP and neighboring mainland countries. The objectives are to describe the history of A. coluzzii establishment in STP, specifically to address several questions germane to their suitability as sites for a field trial release of genetically engineered mosquitoes (GEMs). These questions include: (i) What are the origins of A. coluzzii populations in STP?; (ii) How many introductions occurred?; (iii) When was A. coluzzii introduced into STP? and (iv) Is there ongoing, contemporary gene flow into STP from mainland populations? Phylogenetic analysis and haplotype networks were constructed from sequences of 345 A. coluzzii from STP, and 107 individuals from 10 countries on or near the west coast of Africa. Analysis of these data suggest that there have been two introductions of A. coluzzii onto the island of São Tomé that occurred roughly 500 years ago and that these originated from mainland West Africa. It appears that A. coluzzii has never been introduced into Príncipe Island directly from mainland Africa, but there have been at least four introductions originating from São Tomé. Our findings provide further support for the notion that contemporary populations of A. coluzzii on São Tomé and Príncipe are genetically isolated from mainland populations of this mosquito species.
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Liu C, Cao J, Zhang H, Wu J, Yin J. Profiling of Transcriptome-Wide N6-Methyladenosine (m6A) Modifications and Identifying m6A Associated Regulation in Sperm Tail Formation in Anopheles sinensis. Int J Mol Sci 2022; 23:ijms23094630. [PMID: 35563020 PMCID: PMC9101273 DOI: 10.3390/ijms23094630] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 04/19/2022] [Accepted: 04/19/2022] [Indexed: 12/13/2022] Open
Abstract
Recent discoveries of reversible N6-methyladenosine (m6A) methylation on messenger RNA (mRNA) and mapping of m6A methylomes in many species have revealed potential regulatory functions of this RNA modification by m6A players—writers, readers, and erasers. Here, we first profile transcriptome-wide m6A in female and male Anopheles sinensis and reveal that m6A is also a highly conserved modification of mRNA in mosquitoes. Distinct from mammals and yeast but similar to Arabidopsis thaliana, m6A in An. sinensis is enriched not only around the stop codon and within 3′-untranslated regions but also around the start codon and 5′-UTR. Gene ontology analysis indicates the unique distribution pattern of m6A in An. sinensis is associated with mosquito sex-specific pathways such as tRNA wobble uridine modification and phospholipid-binding in females, and peptidoglycan catabolic process, exosome and signal recognition particle, endoplasmic reticulum targeting, and RNA helicase activity in males. The positive correlation between m6A deposition and mRNA abundance indicates that m6A can play a role in regulating gene expression in mosquitoes. Furthermore, many spermatogenesis-associated genes, especially those related to mature sperm flagellum formation, are positively modulated by m6A methylation. A transcriptional regulatory network of m6A in An. sinensis is first profiled in the present study, especially in spermatogenesis, which may provide a new clue for the control of this disease-transmitting vector.
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Liu Y, Champer J. Modelling homing suppression gene drive in haplodiploid organisms. Proc Biol Sci 2022; 289:20220320. [PMID: 35414240 PMCID: PMC9006016 DOI: 10.1098/rspb.2022.0320] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 03/21/2022] [Indexed: 01/13/2023] Open
Abstract
Gene drives have shown great promise for suppression of pest populations. These engineered alleles can function by a variety of mechanisms, but the most common is the CRISPR homing drive, which converts wild-type alleles to drive alleles in the germline of heterozygotes. Some potential target species are haplodiploid, in which males develop from unfertilized eggs and thus have only one copy of each chromosome. This prevents drive conversion, a substantial disadvantage compared to diploids where drive conversion can take place in both sexes. Here, we study homing suppression gene drives in haplodiploids and find that a drive targeting a female fertility gene could still be successful. However, such drives are less powerful than in diploids and suffer more from functional resistance alleles. They are substantially more vulnerable to high resistance allele formation in the embryo owing to maternally deposited Cas9 and guide RNA and also to somatic cleavage activity. Examining spatial models where organisms move over a continuous landscape, we find that haplodiploid suppression drives surprisingly perform nearly as well as in diploids, possibly owing to their ability to spread further before inducing strong suppression. Together, these results indicate that gene drive can potentially be used to effectively suppress haplodiploid populations.
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Affiliation(s)
- Yiran Liu
- Center for Bioinformatics, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 People's Republic of China
| | - Jackson Champer
- Center for Bioinformatics, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 People's Republic of China
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40
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Carballar-Lejarazú R, Tushar T, Pham TB, James AA. Cas9-mediated maternal-effect and derived resistance alleles in a gene-drive strain of the African malaria vector mosquito, Anopheles gambiae. Genetics 2022; 221:6564662. [PMID: 35389492 PMCID: PMC9157122 DOI: 10.1093/genetics/iyac055] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 03/30/2022] [Indexed: 11/24/2022] Open
Abstract
CRISPR/Cas9 technologies are important tools for the development of gene-drive systems to modify mosquito vector populations to control the transmission of pathogens that cause diseases such as malaria. However, one of the challenges for current Cas9-based drive systems is their ability to produce drive-resistant alleles resulting from insertions and deletions (indels) caused principally by nonhomologous end-joining following chromosome cleavage. Rapid increases in the frequency of such alleles may impair gene-drive dynamics. We explored the generation of indels in the germline and somatic cells in female gene-drive lineages using a series of selective crosses between a gene-drive line, AgNosCd-1, and wild-type mosquitoes. We find that potential drive-resistant mutant alleles are generated largely during embryonic development, most likely caused by deposition of the Cas9 endonuclease and guide RNAs in oocytes and resulting embryos by homozygous and hemizygous gene-drive mothers.
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Affiliation(s)
- Rebeca Carballar-Lejarazú
- Department of Microbiology & Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA
| | - Taylor Tushar
- Department of Microbiology & Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA
| | - Thai Binh Pham
- Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA 92697-3900, USA
| | - Anthony A James
- Department of Microbiology & Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA.,Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA 92697-3900, USA
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Chae K, Dawson C, Valentin C, Contreras B, Zapletal J, Myles KM, Adelman ZN. Engineering a self-eliminating transgene in the yellow fever mosquito, Aedes aegypti. PNAS NEXUS 2022; 1:pgac037. [PMID: 36713320 PMCID: PMC9802104 DOI: 10.1093/pnasnexus/pgac037] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/22/2022] [Indexed: 02/01/2023]
Abstract
Promising genetics-based approaches are being developed to reduce or prevent the transmission of mosquito-vectored diseases. Less clear is how such transgenes can be removed from the environment, a concern that is particularly relevant for highly invasive gene drive transgenes. Here, we lay the groundwork for a transgene removal system based on single-strand annealing (SSA), a eukaryotic DNA repair mechanism. An SSA-based rescuer strain (kmoRG ) was engineered to have direct repeat sequences (DRs) in the Aedes aegypti kynurenine 3-monooxygenase (kmo) gene flanking the intervening transgenic cargo genes, DsRED and EGFP. Targeted induction of DNA double-strand breaks (DSBs) in the DsRED transgene successfully triggered complete elimination of the entire cargo from the kmoRG strain, restoring the wild-type kmo gene, and thereby, normal eye pigmentation. Our work establishes the framework for strategies to remove transgene sequences during the evaluation and testing of modified strains for genetics-based mosquito control.
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Affiliation(s)
- Keun Chae
- 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
| | - Collin Valentin
- 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
| | - Josef Zapletal
- Department of Industrial and Systems Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Kevin M Myles
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
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Verkuijl SAN, Ang JXD, Alphey L, Bonsall MB, Anderson MAE. The Challenges in Developing Efficient and Robust Synthetic Homing Endonuclease Gene Drives. Front Bioeng Biotechnol 2022; 10:856981. [PMID: 35419354 PMCID: PMC8996256 DOI: 10.3389/fbioe.2022.856981] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/04/2022] [Indexed: 11/13/2022] Open
Abstract
Making discrete and precise genetic changes to wild populations has been proposed as a means of addressing some of the world's most pressing ecological and public health challenges caused by insect pests. Technologies that would allow this, such as synthetic gene drives, have been under development for many decades. Recently, a new generation of programmable nucleases has dramatically accelerated technological development. CRISPR-Cas9 has improved the efficiency of genetic engineering and has been used as the principal effector nuclease in different gene drive inheritance biasing mechanisms. Of these nuclease-based gene drives, homing endonuclease gene drives have been the subject of the bulk of research efforts (particularly in insects), with many different iterations having been developed upon similar core designs. We chart the history of homing gene drive development, highlighting the emergence of challenges such as unintended repair outcomes, "leaky" expression, and parental deposition. We conclude by discussing the progress made in developing strategies to increase the efficiency of homing endonuclease gene drives and mitigate or prevent unintended outcomes.
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Affiliation(s)
- Sebald A. N. Verkuijl
- Arthropod Genetics, The Pirbright Institute, Pirbright, United Kingdom
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Joshua X. D. Ang
- Arthropod Genetics, The Pirbright Institute, Pirbright, United Kingdom
| | - Luke Alphey
- Arthropod Genetics, The Pirbright Institute, Pirbright, United Kingdom
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CRISPR-mediated knockout of cardinal and cinnabar eye pigmentation genes in the western tarnished plant bug. Sci Rep 2022; 12:4917. [PMID: 35322099 PMCID: PMC8943060 DOI: 10.1038/s41598-022-08908-4] [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: 11/22/2021] [Accepted: 03/11/2022] [Indexed: 11/08/2022] Open
Abstract
The western tarnished plant bug, Lygus hesperus, is a key hemipteran pest of numerous agricultural, horticultural, and industrial crops in the western United States and Mexico. A lack of genetic tools in L. hesperus hinders progress in functional genomics and in developing innovative pest control methods such as gene drive. Here, using RNA interference (RNAi) against cardinal (LhCd), cinnabar (LhCn), and white (LhW), we showed that knockdown of LhW was lethal to developing embryos, while knockdown of LhCd or LhCn produced bright red eye phenotypes, in contrast to wild-type brown eyes. We further used CRISPR/Cas9 (clustered regularly interspaced palindromic repeats/CRISPR-associated) genome editing to generate germline knockouts of both LhCd (Card) and LhCn (Cinn), producing separate strains of L. hesperus characterized by mutant eye phenotypes. Although the cardinal knockout strain Card exhibited a gradual darkening of the eyes to brown typical of the wild-type line later in nymphal development, we observed bright red eyes throughout all life stages in the cinnabar knockout strain Cinn, making it a viable marker for tracking gene editing in L. hesperus. These results provide evidence that CRISPR/Cas9 gene editing functions in L. hesperus and that eye pigmentation genes are useful for tracking the successful genetic manipulation of this insect.
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Cook F, Bull JJ, Gomulkiewicz R. Gene drive escape from resistance depends on mechanism and ecology. Evol Appl 2022; 15:721-734. [PMID: 35603023 PMCID: PMC9108321 DOI: 10.1111/eva.13358] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 11/26/2022] Open
Abstract
Gene drives can potentially be used to suppress pest populations, and the advent of CRISPR technology has made it feasible to engineer them in many species, especially insects. What remains largely unknown for implementations is whether antidrive resistance will evolve to block the population suppression. An especially serious threat to some kinds of drive is mutations in the CRISPR cleavage sequence that block the action of CRISPR, but designs have been proposed to avoid this type of resistance. Various types of resistance at loci away from the cleavage site remain a possibility, which is the focus here. It is known that modest‐effect suppression drives can essentially “outrun” unlinked resistance even when that resistance is present from the start. We demonstrate here how the risk of evolving (unlinked) resistance can be further reduced without compromising overall suppression by introducing multiple suppression drives or by designing drives with specific ecological effects. However, we show that even modest‐effect suppression drives remain vulnerable to the evolution of extreme levels of inbreeding, which halt the spread of the drive without actually interfering with its mechanism. The landscape of resistance evolution against suppression drives is therefore complex, but avenues exist for enhancing gene drive success.
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Affiliation(s)
- Forest Cook
- School of Electrical Engineering & Computer Science Washington State University Pullman WA 99164 USA
| | - James J. Bull
- Dept of Biological Sciences University of Idaho Moscow ID 83843 USA
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Brey J, Sai Sudhakar BMM, Gersch K, Ford T, Glancey M, West J, Padmanabhan S, Harris AF, Goodwin A. Modified Mosquito Programs’ Surveillance Needs and An Image-Based Identification Tool to Address Them. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2021.810062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Effective mosquito surveillance and control relies on rapid and accurate identification of mosquito vectors and confounding sympatric species. As adoption of modified mosquito (MM) control techniques has increased, the value of monitoring the success of interventions has gained recognition and has pushed the field away from traditional ‘spray and pray’ approaches. Field evaluation and monitoring of MM control techniques that target specific species require massive volumes of surveillance data involving species-level identifications. However, traditional surveillance methods remain time and labor-intensive, requiring highly trained, experienced personnel. Health districts often lack the resources needed to collect essential data, and conventional entomological species identification involves a significant learning curve to produce consistent high accuracy data. These needs led us to develop MosID: a device that allows for high-accuracy mosquito species identification to enhance capability and capacity of mosquito surveillance programs. The device features high-resolution optics and enables batch image capture and species identification of mosquito specimens using computer vision. While development is ongoing, we share an update on key metrics of the MosID system. The identification algorithm, tested internally across 16 species, achieved 98.4 ± 0.6% % macro F1-score on a dataset of known species, unknown species used in training, and species reserved for testing (species, specimens respectively: 12, 1302; 12, 603; 7, 222). Preliminary user testing showed specimens were processed with MosID at a rate ranging from 181-600 specimens per hour. We also discuss other metrics within technical scope, such as mosquito sex and fluorescence detection, that may further support MM programs.
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Roberts AJ, Thizy D. Articulating ethical principles guiding Target Malaria's engagement strategy. Malar J 2022; 21:35. [PMID: 35123487 PMCID: PMC8818152 DOI: 10.1186/s12936-022-04062-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 01/26/2022] [Indexed: 12/31/2022] Open
Abstract
Progress in gene drive research has engendered a lively discussion about community engagement and the ethical standards the work hinges on. While there is broad agreement regarding ethical principles and established best practices for conducting clinical public health research, projects developing area-wide vector control technologies and initiating ambitious engagement strategies raise specific questions: who to engage, when to engage, and how? When responding to these fundamental questions, with few best practices available for guidance, projects need to reflect on and articulate the ethical principles that motivate and justify their approach. Target Malaria is a not-for-profit research consortium that aims to develop and share malaria control and elimination technology. The consortium is currently investigating the potential of a genetic technique called gene drive to control populations of malaria vectoring mosquito species Anopheles gambiae. Due to the potentially broad geographical, environmental impact of gene drive technology, Target Malaria has committed to a robust form of tailored engagement with the local communities in Burkina Faso, Mali, and Uganda, where research activities are currently taking place. This paper presents the principles guiding Target Malaria's engagement strategy. Herein the authors (i) articulate the principles; (ii) explain the rationale for selecting them; (iii) share early lessons about the application of the principles. Since gene drive technology is an emerging technology, with few best practices available for guidance, the authors hope by sharing these lessons, to add to the growing literature regarding engagement strategies and practices for area-wide vector control, and more specifically, for gene drive research.
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Affiliation(s)
- Aaron J Roberts
- Institute On Ethics and Policy for Innovation, McMaster University, Hamilton, Canada
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Bunting MD, Pfitzner C, Gierus L, White M, Piltz S, Thomas PQ. Generation of Gene Drive Mice for Invasive Pest Population Suppression. Methods Mol Biol 2022; 2495:203-230. [PMID: 35696035 DOI: 10.1007/978-1-0716-2301-5_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Gene drives are genetic elements that are transmitted to greater than 50% of offspring and have potential for population modification or suppression. While gene drives are known to occur naturally, the recent emergence of CRISPR-Cas9 genome-editing technology has enabled generation of synthetic gene drives in a range of organisms including mosquitos, flies, and yeast. For example, studies in Anopheles mosquitos have demonstrated >95% transmission of CRISPR-engineered gene drive constructs, providing a possible strategy for malaria control. Recently published studies have also indicated that it may be possible to develop gene drive technology in invasive rodents such as mice. Here, we discuss the prospects for gene drive development in mice, including synthetic "homing drive" and X-shredder strategies as well as modifications of the naturally occurring t haplotype. We also provide detailed protocols for generation of gene drive mice through incorporation of plasmid-based transgenes in a targeted and non-targeted manner. Importantly, these protocols can be used for generating transgenic mice for any project that requires insertion of kilobase-scale transgenes such as knock-in of fluorescent reporters, gene swaps, overexpression/ectopic expression studies, and conditional "floxed" alleles.
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Affiliation(s)
- Mark D Bunting
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Chandran Pfitzner
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Luke Gierus
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Melissa White
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia
- South Australian Genome Editing Facility, North Terrace, Adelaide, SA, Australia
| | - Sandra Piltz
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia
- South Australian Genome Editing Facility, North Terrace, Adelaide, SA, Australia
| | - Paul Q Thomas
- School of Medicine, University of Adelaide, North Terrace, Adelaide, SA, Australia.
- South Australian Genome Editing Facility, North Terrace, Adelaide, SA, Australia.
- South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, Australia.
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Metchanun N, Borgemeister C, Amzati G, von Braun J, Nikolov M, Selvaraj P, Gerardin J. Modeling impact and cost-effectiveness of driving-Y gene drives for malaria elimination in the Democratic Republic of the Congo. Evol Appl 2022; 15:132-148. [PMID: 35126652 PMCID: PMC8792473 DOI: 10.1111/eva.13331] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 11/15/2021] [Accepted: 11/29/2021] [Indexed: 12/17/2022] Open
Abstract
Malaria elimination will be challenging in countries that currently continue to bear high malaria burden. Sex-ratio-distorting gene drives, such as driving-Y, could play a role in an integrated elimination strategy if they can effectively suppress vector populations. Using a spatially explicit, agent-based model of malaria transmission in eight provinces spanning the range of transmission intensities across the Democratic Republic of the Congo, we predict the impact and cost-effectiveness of integrating driving-Y gene drive mosquitoes in malaria elimination strategies that include existing interventions such as insecticide-treated nets and case management of symptomatic malaria. Gene drive mosquitoes could eliminate malaria and were the most cost-effective intervention overall if the drive component was highly effective with at least 95% X-shredder efficiency at relatively low fertility cost, and associated cost of deployment below 7.17 $int per person per year. Suppression gene drive could be a cost-effective supplemental intervention for malaria elimination, but tight constraints on drive effectiveness and cost ceilings may limit its feasibility.
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Affiliation(s)
| | | | - Gaston Amzati
- Université Evangélique en AfriqueBukavuDemocratic Republic of the Congo
| | | | | | | | - Jaline Gerardin
- Institute for Disease ModelingBellevueWashingtonUSA
- Department of Preventive Medicine and Institute for Global HealthNorthwestern UniversityChicagoIllinoisUSA
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Siddall A, Harvey-Samuel T, Chapman T, Leftwich PT. Manipulating Insect Sex Determination Pathways for Genetic Pest Management: Opportunities and Challenges. Front Bioeng Biotechnol 2022; 10:867851. [PMID: 35837548 PMCID: PMC9274970 DOI: 10.3389/fbioe.2022.867851] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 06/01/2022] [Indexed: 12/04/2022] Open
Abstract
Sex determination pathways in insects are generally characterised by an upstream primary signal, which is highly variable across species, and that regulates the splicing of a suite of downstream but highly-conserved genes (transformer, doublesex and fruitless). In turn, these downstream genes then regulate the expression of sex-specific characteristics in males and females. Identification of sex determination pathways has and continues to be, a critical component of insect population suppression technologies. For example, "first-generation" transgenic technologies such as fsRIDL (Female-Specific Release of Insects carrying Dominant Lethals) enabled efficient selective removal of females from a target population as a significant improvement on the sterile insect technique (SIT). Second-generation technologies such as CRISPR/Cas9 homing gene drives and precision-guided SIT (pgSIT) have used gene editing technologies to manipulate sex determination genes in vivo. The development of future, third-generation control technologies, such as Y-linked drives, (female to male) sex-reversal, or X-shredding, will require additional knowledge of aspects of sexual development, including a deeper understanding of the nature of primary signals and dosage compensation. This review shows how knowledge of sex determination in target pest species is fundamental to all phases of the development of control technologies.
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Affiliation(s)
- Alex Siddall
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Tim Harvey-Samuel
- Arthropod Genetics, The Pirbright Institute, Pirbright, United Kingdom
| | - Tracey Chapman
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Philip T Leftwich
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
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Abstract
Gene drives are selfish genetic elements that are transmitted to progeny at super-Mendelian (>50%) frequencies. Recently developed CRISPR-Cas9-based gene-drive systems are highly efficient in laboratory settings, offering the potential to reduce the prevalence of vector-borne diseases, crop pests and non-native invasive species. However, concerns have been raised regarding the potential unintended impacts of gene-drive systems. This Review summarizes the phenomenal progress in this field, focusing on optimal design features for full-drive elements (drives with linked Cas9 and guide RNA components) that either suppress target mosquito populations or modify them to prevent pathogen transmission, allelic drives for updating genetic elements, mitigating strategies including trans-complementing split-drives and genetic neutralizing elements, and the adaptation of drive technology to other organisms. These scientific advances, combined with ethical and social considerations, will facilitate the transparent and responsible advancement of these technologies towards field implementation.
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Affiliation(s)
- Ethan Bier
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, USA.
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