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Harvey-Samuel T, Feng X, Okamoto EM, Purusothaman DK, Leftwich PT, Alphey L, Gantz VM. CRISPR-based gene drives generate super-Mendelian inheritance in the disease vector Culex quinquefasciatus. Nat Commun 2023; 14:7561. [PMID: 37985762 PMCID: PMC10662442 DOI: 10.1038/s41467-023-41834-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 09/21/2023] [Indexed: 11/22/2023] Open
Abstract
Culex mosquitoes pose a significant public health threat as vectors for a variety of diseases including West Nile virus and lymphatic filariasis, and transmit pathogens threatening livestock, companion animals, and endangered birds. Rampant insecticide resistance makes controlling these mosquitoes challenging and necessitates the development of new control strategies. Gene drive technologies have made significant progress in other mosquito species, although similar advances have been lagging in Culex. Here we test a CRISPR-based homing gene drive for Culex quinquefasciatus, and show that the inheritance of two split-gene-drive transgenes, targeting different loci, are biased in the presence of a Cas9-expressing transgene although with modest efficiencies. Our findings extend the list of disease vectors where engineered homing gene drives have been demonstrated to include Culex alongside Anopheles and Aedes, and pave the way for future development of these technologies to control Culex mosquitoes.
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Affiliation(s)
- Tim Harvey-Samuel
- Arthropod Genetics Group, The Pirbright Institute, Woking, GU24 0NF, UK
| | - Xuechun Feng
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA.
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Guangdong, 518106, Shenzhen, China.
| | - Emily M Okamoto
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Deepak-Kumar Purusothaman
- Arthropod Genetics Group, The Pirbright Institute, Woking, GU24 0NF, UK
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Philip T Leftwich
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Luke Alphey
- Arthropod Genetics Group, The Pirbright Institute, Woking, GU24 0NF, UK.
- Biology Department, University of York, York, YO10 5DD, UK.
| | - Valentino M Gantz
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA.
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2
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Harvey-Samuel T, Feng X, Okamoto EM, Purusothaman DK, Leftwich PT, Alphey L, Gantz VM. CRISPR-based gene drives generate super-Mendelian inheritance in the disease vector Culex quinquefasciatus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.12.544656. [PMID: 37398284 PMCID: PMC10312623 DOI: 10.1101/2023.06.12.544656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Culex mosquitoes pose a significant public health threat as vectors for a variety of diseases including West Nile virus and lymphatic filariasis, and transmit pathogens threatening livestock, companion animals, and endangered birds. Rampant insecticide resistance makes controlling these mosquitoes challenging and necessitates the development of new control strategies. Gene drive technologies have made significant progress in other mosquito species, although similar advances have been lagging in Culex. Here we test the first CRISPR-based homing gene drive for Culex quinquefasciatus, demonstrating the possibility of using this technology to control Culex mosquitoes. Our results show that the inheritance of two split-gene-drive transgenes, targeting different loci, are biased in the presence of a Cas9-expressing transgene although with modest efficiencies. Our findings extend the list of disease vectors where engineered homing gene drives have been demonstrated to include Culex alongside Anopheles and Aedes, and pave the way for future development of these technologies to control Culex mosquitoes.
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Affiliation(s)
- Tim Harvey-Samuel
- Arthropod Genetics Group, The Pirbright Institute, Woking, UK, GU24 0NF
| | - Xuechun Feng
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA 92093
| | - Emily M Okamoto
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA 92093
| | - Deepak-Kumar Purusothaman
- Arthropod Genetics Group, The Pirbright Institute, Woking, UK, GU24 0NF
- Present address: MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, UK G12 8QQ
| | - Philip T Leftwich
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK, NR4 7TJ
| | - Luke Alphey
- Present address: Biology Department, University of York, York, UK, YO10 5DD
| | - Valentino M Gantz
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA 92093
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3
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Bottino-Rojas V, James AA. Use of Insect Promoters in Genetic Engineering to Control Mosquito-Borne Diseases. Biomolecules 2022; 13:biom13010016. [PMID: 36671401 PMCID: PMC9855440 DOI: 10.3390/biom13010016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 12/16/2022] [Accepted: 12/18/2022] [Indexed: 12/24/2022] Open
Abstract
Mosquito transgenesis and gene-drive technologies provide the basis for developing promising new tools for vector-borne disease prevention by either suppressing wild mosquito populations or reducing their capacity from transmitting pathogens. Many studies of the regulatory DNA and promoters of genes with robust sex-, tissue- and stage-specific expression profiles have supported the development of new tools and strategies that could bring mosquito-borne diseases under control. Although the list of regulatory elements available is significant, only a limited set of those can reliably drive spatial-temporal expression. Here, we review the advances in our ability to express beneficial and other genes in mosquitoes, and highlight the information needed for the development of new mosquito-control and anti-disease strategies.
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Affiliation(s)
- Vanessa Bottino-Rojas
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697, USA
| | - Anthony A. James
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697, USA
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
- Correspondence:
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4
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Raban R, Gendron WAC, Akbari OS. A perspective on the expansion of the genetic technologies to support the control of neglected vector-borne diseases and conservation. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.999273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
Genetic-based technologies are emerging as promising tools to support vector population control. Vectors of human malaria and dengue have been the main focus of these development efforts, but in recent years these technologies have become more flexible and adaptable and may therefore have more wide-ranging applications. Culex quinquefasciatus, for example, is the primary vector of avian malaria in Hawaii and other tropical islands. Avian malaria has led to the extinction of numerous native bird species and many native bird species continue to be threatened as climate change is expanding the range of this mosquito. Genetic-based technologies would be ideal to support avian malaria control as they would offer alternatives to interventions that are difficult to implement in natural areas, such as larval source reduction, and limit the need for chemical insecticides, which can harm beneficial species in these natural areas. This mosquito is also an important vector of human diseases, such as West Nile and Saint Louis encephalitis viruses, so genetic-based control efforts for this species could also have a direct impact on human health. This commentary will discuss the current state of development and future needs for genetic-based technologies in lesser studied, but important disease vectors, such as C. quinquefasciatus, and make comparisons to technologies available in more studied vectors. While most current genetic control focuses on human disease, we will address the impact that these technologies could have on both disease and conservation focused vector control efforts and what is needed to prepare these technologies for evaluation in the field. The versatility of genetic-based technologies may result in the development of many important tools to control a variety of vectors that impact human, animal, and ecosystem health.
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5
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Dong S, Dong Y, Simões ML, Dimopoulos G. Mosquito transgenesis for malaria control. Trends Parasitol 2021; 38:54-66. [PMID: 34483052 DOI: 10.1016/j.pt.2021.08.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/01/2021] [Accepted: 08/03/2021] [Indexed: 12/14/2022]
Abstract
Malaria is one of the deadliest diseases. Because of the ineffectiveness of current malaria-control methods, several novel mosquito vector-based control strategies have been proposed to supplement existing control strategies. Mosquito transgenesis and gene drive have emerged as promising tools for preventing the spread of malaria by either suppressing mosquito populations by self-destructing mosquitoes or replacing mosquito populations with disease-refractory populations. Here we review the development of mosquito transgenesis and its application for malaria control, highlighting the transgenic expression of antiparasitic effector genes, inactivation of host factor genes, and manipulation of miRNAs and lncRNAs. Overall, from a malaria-control perspective, mosquito transgenesis is not envisioned as a stand-alone approach; rather, its use is proposed as a complement to existing vector-control strategies.
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Affiliation(s)
- Shengzhang Dong
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Yuemei Dong
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Maria L Simões
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
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6
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Quinn C, Anthousi A, Wondji C, Nolan T. CRISPR-mediated knock-in of transgenes into the malaria vector Anopheles funestus. G3 (BETHESDA, MD.) 2021; 11:6303614. [PMID: 34849822 PMCID: PMC8496255 DOI: 10.1093/g3journal/jkab201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/17/2021] [Indexed: 01/15/2023]
Abstract
The ability to introduce mutations, or transgenes, of choice to precise genomic locations has revolutionized our ability to understand how genes and organisms work. In many mosquito species that are vectors of various human diseases, the advent of CRISPR genome editing tools has shed light on basic aspects of their biology that are relevant to their efficiency as disease vectors. This allows a better understanding of how current control tools work and opens up the possibility of novel genetic control approaches, such as gene drives, that deliberately introduce genetic traits into populations. Yet for the Anopheles funestus mosquito, a significant vector of malaria in sub-Saharan Africa and indeed the dominant vector species in many countries, transgenesis has yet to be achieved. We describe herein an optimized transformation system based on the germline delivery of CRISPR components that allows efficient cleavage of a previously validated genomic site and preferential repair of these cut sites via homology-directed repair (HDR), which allows the introduction of exogenous template sequence, rather than end-joining repair. The rates of transformation achieved are sufficiently high that it should be able to introduce alleles of choice to a target locus, and recover these, without the need to include additional dominant marker genes. Moreover, the high rates of HDR observed suggest that gene drives, which employ an HDR-type mechanism to ensure their proliferation in the genome, may be well suited to work in A. funestus.
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Affiliation(s)
| | - Amalia Anthousi
- Department of Biology, University of Crete, Heraklion 700 13, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion 700 13, Greece
| | - Charles Wondji
- Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaoundé 5, Cameroon
| | - Tony Nolan
- Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
- Corresponding author:
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7
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Purusothaman DK, Shackleford L, Anderson MAE, Harvey-Samuel T, Alphey L. CRISPR/Cas-9 mediated knock-in by homology dependent repair in the West Nile Virus vector Culex quinquefasciatus Say. Sci Rep 2021; 11:14964. [PMID: 34294769 PMCID: PMC8298393 DOI: 10.1038/s41598-021-94065-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/28/2021] [Indexed: 11/27/2022] Open
Abstract
Culex quinquefasciatus Say is a mosquito distributed in both tropical and subtropical regions of the world. It is a night-active, opportunistic blood-feeder and vectors many animal and human diseases, including West Nile Virus and avian malaria. Current vector control methods (e.g. physical/chemical) are increasingly ineffective; use of insecticides also imposes hazards to both human and ecosystem health. Advances in genome editing have allowed the development of genetic insect control methods, which are species-specific and, theoretically, highly effective. CRISPR/Cas9 is a bacteria-derived programmable gene editing tool that is functional in a range of species. We describe the first successful germline gene knock-in by homology dependent repair in C. quinquefasciatus. Using CRISPR/Cas9, we integrated an sgRNA expression cassette and marker gene encoding a fluorescent protein fluorophore (Hr5/IE1-DsRed, Cq7SK-sgRNA) into the kynurenine 3-monooxygenase (kmo) gene. We achieved a minimum transformation rate of 2.8%, similar to rates in other mosquito species. Precise knock-in at the intended locus was confirmed. Insertion homozygotes displayed a white eye phenotype in early-mid larvae and a recessive lethal phenotype by pupation. This work provides an efficient method for engineering C. quinquefasciatus, providing a new tool for developing genetic control tools for this vector.
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Affiliation(s)
| | - Lewis Shackleford
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, Surrey, UK
| | - Michelle A E Anderson
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, Surrey, UK
| | - Tim Harvey-Samuel
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, Surrey, UK
| | - Luke Alphey
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, Surrey, UK.
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8
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Feng X, López Del Amo V, Mameli E, Lee M, Bishop AL, Perrimon N, Gantz VM. Optimized CRISPR tools and site-directed transgenesis towards gene drive development in Culex quinquefasciatus mosquitoes. Nat Commun 2021; 12:2960. [PMID: 34017003 PMCID: PMC8137705 DOI: 10.1038/s41467-021-23239-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 04/21/2021] [Indexed: 12/15/2022] Open
Abstract
Culex mosquitoes are a global vector for multiple human and animal diseases, including West Nile virus, lymphatic filariasis, and avian malaria, posing a constant threat to public health, livestock, companion animals, and endangered birds. While rising insecticide resistance has threatened the control of Culex mosquitoes, advances in CRISPR genome-editing tools have fostered the development of alternative genetic strategies such as gene drive systems to fight disease vectors. However, though gene-drive technology has quickly progressed in other mosquitoes, advances have been lacking in Culex. Here, we develop a Culex-specific Cas9/gRNA expression toolkit and use site-directed homology-based transgenesis to generate and validate a Culex quinquefasciatus Cas9-expressing line. We show that gRNA scaffold variants improve transgenesis efficiency in both Culex quinquefasciatus and Drosophila melanogaster and boost gene-drive performance in the fruit fly. These findings support future technology development to control Culex mosquitoes and provide valuable insight for improving these tools in other species.
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Affiliation(s)
- Xuechun Feng
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Víctor López Del Amo
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Enzo Mameli
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, School of Medicine, Boston, MA, USA
| | - Megan Lee
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Alena L Bishop
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- HHMI, Harvard Medical School, Boston, MA, USA
| | - Valentino M Gantz
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA.
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9
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Nuss A, Sharma A, Gulia-Nuss M. Genetic Manipulation of Ticks: A Paradigm Shift in Tick and Tick-Borne Diseases Research. Front Cell Infect Microbiol 2021; 11:678037. [PMID: 34041045 PMCID: PMC8141593 DOI: 10.3389/fcimb.2021.678037] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 04/16/2021] [Indexed: 12/13/2022] Open
Abstract
Ticks are obligate hematophagous arthropods that are distributed worldwide and are one of the most important vectors of pathogens affecting humans and animals. Despite the growing burden of tick-borne diseases, research on ticks has lagged behind other arthropod vectors, such as mosquitoes. This is largely because of challenges in applying functional genomics and genetic tools to the idiosyncrasies unique to tick biology, particularly techniques for stable genetic transformations. CRISPR-Cas9 is transforming non-model organism research; however, successful germline editing has yet to be accomplished in ticks. Here, we review the ancillary methods needed for transgenic tick development and the use of CRISPR/Cas9, the most promising gene-editing approach, for tick genetic transformation.
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Affiliation(s)
- Andrew Nuss
- Department of Biochemistry and Molecular Biology, The University of Nevada, Reno, NV, United States
- Department of Agriculture, Veterinary, and Rangeland Sciences, The University of Nevada, Reno, NV, United States
| | - Arvind Sharma
- Department of Biochemistry and Molecular Biology, The University of Nevada, Reno, NV, United States
| | - Monika Gulia-Nuss
- Department of Biochemistry and Molecular Biology, The University of Nevada, Reno, NV, United States
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10
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Lule-Chávez AN, Carballar-Lejarazú R, Cabrera-Ponce JL, Lanz-Mendoza H, Ibarra JE. Genetic transformation of mosquitoes by microparticle bombardment. INSECT MOLECULAR BIOLOGY 2021; 30:30-41. [PMID: 33009687 DOI: 10.1111/imb.12670] [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: 04/15/2020] [Revised: 09/23/2020] [Accepted: 09/28/2020] [Indexed: 06/11/2023]
Abstract
Mosquitoes constitute the major living beings causing human deaths in the world. They are vectors of malaria, yellow fever, dengue, zika, filariases, chikungunya, among other diseases. New strategies to control/eradicate mosquito populations are based on newly developed genetic manipulation techniques. However, genetic transformation of mosquitoes is a major technical bottleneck due to low efficiency, the need of sophisticated equipment, and highly trained personnel. The present report shows the transgenerational genetic transformation of Aedes aegypti, using the particle inflow gun (PIG), by integrating the ecfp gene in the AAEL000582 mosquito gene with the CRISPR-Cas9 technique, achieving a mean efficiency of 44.5% of bombarded individuals (G0) that showed ECFP expression in their tissues, and a mean of 28.5% transformation efficiency measured on G1 individuals. The same transformation technique was used to integrate the egfp/scorpine genes cloned in the Minos transposon pMinHygeGFP into the Anopheles albimanus genome, achieving a mean efficiency of 43.25% of bombarded individuals (G0) that showed EGFP expression in their tissues. Once the technique was standardized, transformation of Ae. aegypti neonate larvae and An. albimanus eggs was achieved when exposed to gold microparticle bombardment. Integration of genes and heterologous protein expression were confirmed by PCR, sequencing, fluorescent microscopy, mass spectrometry, Western blot and dot blot analyses. Transgenerational inheritance of the transgenes was observed only on Ae. aegypti, as all transformed An. albimanus individuals died at the pupal stage of the G0 generation.
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Affiliation(s)
- A N Lule-Chávez
- Centro de Investigación y de Estudios Avanzados del IPN (Cinvestav-IPN), Unidad Irapuato, Irapuato, Mexico
| | - R Carballar-Lejarazú
- Centro de Investigación y de Estudios Avanzados del IPN (Cinvestav-IPN), Unidad Irapuato, Irapuato, Mexico
- Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Mexico
| | - J L Cabrera-Ponce
- Centro de Investigación y de Estudios Avanzados del IPN (Cinvestav-IPN), Unidad Irapuato, Irapuato, Mexico
| | - H Lanz-Mendoza
- Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Mexico
| | - J E Ibarra
- Centro de Investigación y de Estudios Avanzados del IPN (Cinvestav-IPN), Unidad Irapuato, Irapuato, Mexico
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11
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Navarro-Payá D, Flis I, Anderson MAE, Hawes P, Li M, Akbari OS, Basu S, Alphey L. Targeting female flight for genetic control of mosquitoes. PLoS Negl Trop Dis 2020; 14:e0008876. [PMID: 33270627 PMCID: PMC7714197 DOI: 10.1371/journal.pntd.0008876] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/12/2020] [Indexed: 01/04/2023] Open
Abstract
Aedes aegypti Act4 is a paralog of the Drosophila melanogaster indirect flight muscle actin gene Act88F. Act88F has been shown to be haploinsufficient for flight in both males and females (amorphic mutants are dominant). Whereas Act88F is expressed in indirect flight muscles of both males and females, expression of Act4 is substantially female-specific. We therefore used CRISPR/Cas9 and homology directed repair to examine the phenotype of Act4 mutants in two Culicine mosquitoes, Aedes aegypti and Culex quinquefasciatus. A screen for dominant female-flightless mutants in Cx. quinquefasciatus identified one such mutant associated with a six base pair deletion in the CxAct4 coding region. A similar screen in Ae. aegypti identified no dominant mutants. Disruption of the AeAct4 gene by homology-dependent insertion of a fluorescent protein marker cassette gave a recessive female-flightless phenotype in Ae. aegypti. Reproducing the six-base deletion from Cx. quinquefasciatus in Ae. aegypti using oligo-directed mutagenesis generated dominant female-flightless mutants and identified additional dominant female-flightless mutants with other in-frame insertions or deletions. Our data indicate that loss of function mutations in the AeAct4 gene are recessive but that short in-frame deletions produce dominant-negative versions of the AeAct4 protein that interfere with flight muscle function. This makes Act4 an interesting candidate for genetic control methods, particularly population-suppression gene drives targeting female viability/fertility.
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Affiliation(s)
| | - Ilona Flis
- Arthropod Genetics, The Pirbright Institute, Pirbright, United Kingdom
| | | | - Philippa Hawes
- Bioimaging, The Pirbright Institute, Pirbright, United Kingdom
| | - Ming Li
- Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, California, United States of America
| | - Omar S. Akbari
- Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, California, United States of America
| | - Sanjay Basu
- Arthropod Genetics, The Pirbright Institute, Pirbright, United Kingdom
| | - Luke Alphey
- Arthropod Genetics, The Pirbright Institute, Pirbright, United Kingdom
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12
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Smith RC. Highlights in Medical Entomology, 2019: Familiar Foes and New Frontiers. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:1349-1353. [PMID: 32667035 PMCID: PMC7716807 DOI: 10.1093/jme/tjaa120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Indexed: 06/11/2023]
Abstract
The 2019 Entomological Society of America annual meeting was held in St. Louis, Missouri, just blocks away from the iconic Gateway Arch. Representing a 'gateway to the West', this inspired the theme of the Highlights in Medical Entomology to reflect on the accomplishments of the past year as we move into a 'new frontier' of vector biology research. Papers were selected broadly across arthropods that influence public health, focusing on topics ranging from West Nile virus transmission, ticks and tick-borne disease, to advances in genetics and 'big data' studies. This included current perspectives on West Nile virus ecology and epidemiology, which has now been endemic in the United States for 20 yr. Additional topics such as the advantages of citizen science and the importance of scientific communication were also discussed. Together, these papers demonstrate the achievements of the vector community while emphasizing the challenges that we collectively face to reduce the burden of vector-borne disease.
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Affiliation(s)
- Ryan C Smith
- Department of Entomology, Iowa State University, Ames, IA
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13
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Li M, Li T, Liu N, Raban RR, Wang X, Akbari OS. Methods for the generation of heritable germline mutations in the disease vector Culex quinquefasciatus using clustered regularly interspaced short palindrome repeats-associated protein 9. INSECT MOLECULAR BIOLOGY 2020; 29:214-220. [PMID: 31693260 DOI: 10.1111/imb.12626] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 08/21/2019] [Accepted: 10/31/2019] [Indexed: 06/10/2023]
Abstract
Culex quinquefasciatus is a vector of many diseases that adversely impact human and animal health; however, compared to other mosquito vectors limited genome engineering technologies have been characterized for this vector. Clustered regularly interspaced short palindrome repeats-associated protein 9 (CRISPR-Cas9) based technologies are a powerful tool for genome engineering and functional genetics and consequently have transformed genetic studies in many organisms. Our objective was to improve upon the limited technologies available for genome editing in C. quinquefasciatus to create a reproducible and straightforward method for CRISPR-Cas9-targeted mutagenesis in this vector. Here we describe methods to achieve high embryo survival and mutagenesis rates and we provide details on the injection supplies and procedures, embryo handling and guide RNA (gRNA) target designs. Through these efforts, we achieved embryo survival rates and germline mutagenesis rates that greatly exceed previously reported rates in this vector. This work is also the first to characterize the white gene marker in this species, which is a valuable phenotypic marker for future transgenesis or mutagenesis of this vector. Overall, these tools provide the framework for future functional genetic studies in this important disease vector and may support the development of future gene drive and genetic technologies that can be used to control this vector.
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Affiliation(s)
- M Li
- Section of Cell and Developmental Biology, University of California, San Diego, CA, USA
| | - T Li
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - N Liu
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - R R Raban
- Section of Cell and Developmental Biology, University of California, San Diego, CA, USA
| | - X Wang
- College of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - O S Akbari
- Section of Cell and Developmental Biology, University of California, San Diego, CA, USA
- Tata Institute for Genetics and Society, University of California, CA, USA
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14
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Anderson ME, Mavica J, Shackleford L, Flis I, Fochler S, Basu S, Alphey L. CRISPR/Cas9 gene editing in the West Nile Virus vector, Culex quinquefasciatus Say. PLoS One 2019; 14:e0224857. [PMID: 31714905 PMCID: PMC6850532 DOI: 10.1371/journal.pone.0224857] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 10/23/2019] [Indexed: 12/16/2022] Open
Abstract
Culex quinquefasciatus Say is an opportunistic blood feeder with a wide geographic distribution which is also a major vector for a range of diseases of both animals and humans. CRISPR/Cas technologies have been applied to a wide variety of organisms for both applied and basic research purposes. CRISPR/Cas methods open new possibilities for genetic research in non-model organisms of public health importance. In this work we have adapted microinjection techniques commonly used in other mosquito species to Culex quinquefasciatus, and have shown these to be effective at generating homozygous knock-out mutations of a target gene in one generation. This is the first description of the kmo gene and mutant phenotype in this species.
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Affiliation(s)
- Michelle E. Anderson
- Arthropod Genetics, The Pirbright Institute, Pirbright, Woking, England, United Kingdom
| | - Jessica Mavica
- Arthropod Genetics, The Pirbright Institute, Pirbright, Woking, England, United Kingdom
| | - Lewis Shackleford
- Arthropod Genetics, The Pirbright Institute, Pirbright, Woking, England, United Kingdom
| | - Ilona Flis
- Arthropod Genetics, The Pirbright Institute, Pirbright, Woking, England, United Kingdom
| | - Sophia Fochler
- Arthropod Genetics, The Pirbright Institute, Pirbright, Woking, England, United Kingdom
| | - Sanjay Basu
- Arthropod Genetics, The Pirbright Institute, Pirbright, Woking, England, United Kingdom
| | - Luke Alphey
- Arthropod Genetics, The Pirbright Institute, Pirbright, Woking, England, United Kingdom
- * E-mail:
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15
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Abstract
Vector control programs based on population reduction by matings with mass-released sterile insects require the release of only male mosquitoes, as the release of females, even if sterile, would increase the number of biting and potentially disease-transmitting individuals. While small-scale releases demonstrated the applicability of sterile males releases to control the yellow fever mosquito Aedes aegypti, large-scale programs for mosquitoes are currently prevented by the lack of efficient sexing systems in any of the vector species.Different approaches of sexing are pursued, including classical genetic and mechanical methods of sex separation. Another strategy is the development of transgenic sexing systems. Such systems already exist in other insect pests. Genome modification tools could be used to apply similar strategies to mosquitoes. Three major tools to modify mosquito genomes are currently used: transposable elements, site-specific recombination systems, and genome editing via TALEN or CRISPR/Cas. All three can serve the purpose of developing sexing systems and vector control strains in mosquitoes in two ways: first, via their use in basic research. A better understanding of mosquito biology, including the sex-determining pathways and the involved genes can greatly facilitate the development of sexing strains. Moreover, basic research can help to identify other regulatory elements and genes potentially useful for the construction of transgenic sexing systems. Second, these genome modification tools can be used to apply the gained knowledge to build and test mosquito sexing strains for vector control.
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Affiliation(s)
- Irina Häcker
- Institute for Insect Biotechnology, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany.
| | - Marc F Schetelig
- Institute for Insect Biotechnology, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany
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16
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Baculovirus as an efficient vector for gene delivery into mosquitoes. Sci Rep 2018; 8:17778. [PMID: 30542209 PMCID: PMC6290771 DOI: 10.1038/s41598-018-35463-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 11/05/2018] [Indexed: 02/06/2023] Open
Abstract
Efficient gene delivery technologies play an essential role in the gene functional analyses that are necessary for basic and applied researches. Mosquitoes are ubiquitous insects, responsible for transmitting many deadly arboviruses causing millions of human deaths every year. The lack of efficient and flexible gene delivery strategies in mosquitoes are among the major hurdles for the study of mosquito biology and mosquito-pathogen interactions. We found that Autographa californica multiple nucleopolyhedrovirus (AcMNPV), the type baculovirus species, can efficiently transduce mosquito cells without viral propagation, allowing high level gene expression upon inducement by suitable promoters without obvious negative effects on cell propagation and viability. AcMNPV transduces into several mosquito cell types, efficiently than in commonly used mammalian cell lines and classical plasmid DNA transfection approaches. We demonstrated the application of this system by expressing influenza virus neuraminidase (NA) into mosquito hosts. Moreover, AcMNPV can transduce both larvae and adults of essentially all blood-sucking mosquito genera, resulting in bright fluorescence in insect bodies with little or no tissue barriers. Our experiments establish baculovirus as a convenient and powerful gene delivery vector in vitro and in vivo that will greatly benefit research into mosquito gene regulation, development and the study of mosquito-borne viruses.
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17
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Abstract
Technologies for controlling mosquito vectors based on genetic manipulation and the release of genetically modified mosquitoes (GMMs) are gaining ground. However, concrete epidemiological evidence of their effectiveness, sustainability, and impact on the environment and nontarget species is lacking; no reliable ecological evidence on the potential interactions among GMMs, target populations, and other mosquito species populations exists; and no GMM technology has yet been approved by the WHO Vector Control Advisory Group. Our opinion is that, although GMMs may be considered a promising control tool, more studies are needed to assess their true effectiveness, risks, and benefits. Overall, several lines of evidence must be provided before GMM-based control strategies can be used under the integrated vector management framework.
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Affiliation(s)
- André B B Wilke
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - John C Beier
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Giovanni Benelli
- Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy; The BioRobotics Institute, Sant'Anna School of Advanced Studies, viale Rinaldo Piaggio 34, 56025 Pontedera, Pisa, Italy.
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18
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Macias VM, Ohm JR, Rasgon JL. Gene Drive for Mosquito Control: Where Did It Come from and Where Are We Headed? INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14091006. [PMID: 28869513 PMCID: PMC5615543 DOI: 10.3390/ijerph14091006] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 08/25/2017] [Accepted: 08/28/2017] [Indexed: 02/08/2023]
Abstract
Mosquito-borne pathogens place an enormous burden on human health. The existing toolkit is insufficient to support ongoing vector-control efforts towards meeting disease elimination and eradication goals. The perspective that genetic approaches can potentially add a significant set of tools toward mosquito control is not new, but the recent improvements in site-specific gene editing with CRISPR/Cas9 systems have enhanced our ability to both study mosquito biology using reverse genetics and produce genetics-based tools. Cas9-mediated gene-editing is an efficient and adaptable platform for gene drive strategies, which have advantages over innundative release strategies for introgressing desirable suppression and pathogen-blocking genotypes into wild mosquito populations; until recently, an effective gene drive has been largely out of reach. Many considerations will inform the effective use of new genetic tools, including gene drives. Here we review the lengthy history of genetic advances in mosquito biology and discuss both the impact of efficient site-specific gene editing on vector biology and the resulting potential to deploy new genetic tools for the abatement of mosquito-borne disease.
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Affiliation(s)
- Vanessa M Macias
- Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA.
| | - Johanna R Ohm
- Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA 16802, USA.
| | - Jason L Rasgon
- Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA.
- Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA 16802, USA.
- The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA.
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19
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Building early-larval sexing systems for genetic control of the Australian sheep blow fly Lucilia cuprina using two constitutive promoters. Sci Rep 2017; 7:2538. [PMID: 28566730 PMCID: PMC5451413 DOI: 10.1038/s41598-017-02763-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/18/2017] [Indexed: 11/15/2022] Open
Abstract
Transgenic sexing strains (TSS) that carry conditional female lethal genes are advantageous for genetic control programs based on the sterile insect technique (SIT). It is desirable if females die early in development as larval diet is a major cost for mass production facilities. This can be achieved by using a gene promoter that is only active in embryos to drive expression of the tetracycline transactivator (tTA), the transcription factor commonly used in two-component TSS. While an embryo-specific promoter is ideal it may not be essential for assembling an effective TSS as tTA can be repressed by addition of tetracycline to the diet at larval and/or adult stages. Here we have investigated this idea by isolating and employing the promoters from the Lucilia spitting image and actin 5C genes to drive tTA expression in embryos and later stages. L. cuprina TSS with the tTA drivers and tTA-regulated tetO-Lshid effectors produced only females when raised on a limited tetracycline diet. The Lshid transgene contains a sex-specific intron and as a consequence only females produce LsHID protein. TSS females died at early larval stages, which makes the lines advantageous for an SIT program.
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20
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Harvey-Samuel T, Ant T, Alphey L. Towards the genetic control of invasive species. Biol Invasions 2017; 19:1683-1703. [PMID: 28620268 PMCID: PMC5446844 DOI: 10.1007/s10530-017-1384-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 02/11/2017] [Indexed: 11/13/2022]
Abstract
Invasive species remain one of the greatest threats to global biodiversity. Their control would be enhanced through the development of more effective and sustainable pest management strategies. Recently, a novel form of genetic pest management (GPM) has been developed in which the mating behaviour of insect pests is exploited to introduce genetically engineered DNA sequences into wild conspecific populations. These 'transgenes' work in one or more ways to reduce the damage caused by a particular pest, for example reducing its density, or its ability to vector disease. Although currently being developed for use against economically important insect pests, these technologies would be highly appropriate for application against invasive species that threaten biodiversity. Importantly, these technologies have begun to advance in scope beyond insects to vertebrates, which include some of the world's worst invasives. Here we review the current state of this rapidly progressing field and, using an established set of eradication criteria, discuss the characteristics which make GPM technologies suitable for application against invasive pests.
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21
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Liao W, Atkinson CT, LaPointe DA, Samuel MD. Mitigating Future Avian Malaria Threats to Hawaiian Forest Birds from Climate Change. PLoS One 2017; 12:e0168880. [PMID: 28060848 PMCID: PMC5218566 DOI: 10.1371/journal.pone.0168880] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 12/07/2016] [Indexed: 11/23/2022] Open
Abstract
Avian malaria, transmitted by Culex quinquefasciatus mosquitoes in the Hawaiian Islands, has been a primary contributor to population range limitations, declines, and extinctions for many endemic Hawaiian honeycreepers. Avian malaria is strongly influenced by climate; therefore, predicted future changes are expected to expand transmission into higher elevations and intensify and lengthen existing transmission periods at lower elevations, leading to further population declines and potential extinction of highly susceptible honeycreepers in mid- and high-elevation forests. Based on future climate changes and resulting malaria risk, we evaluated the viability of alternative conservation strategies to preserve endemic Hawaiian birds at mid and high elevations through the 21st century. We linked an epidemiological model with three alternative climatic projections from the Coupled Model Intercomparison Project to predict future malaria risk and bird population dynamics for the coming century. Based on climate change predictions, proposed strategies included mosquito population suppression using modified males, release of genetically modified refractory mosquitoes, competition from other introduced mosquitoes that are not competent vectors, evolved malaria-tolerance in native honeycreepers, feral pig control to reduce mosquito larval habitats, and predator control to improve bird demographics. Transmission rates of malaria are predicted to be higher than currently observed and are likely to have larger impacts in high-elevation forests where current low rates of transmission create a refuge for highly-susceptible birds. As a result, several current and proposed conservation strategies will be insufficient to maintain existing forest bird populations. We concluded that mitigating malaria transmission at high elevations should be a primary conservation goal. Conservation strategies that maintain highly susceptible species like Iiwi (Drepanis coccinea) will likely benefit other threatened and endangered Hawai’i species, especially in high-elevation forests. Our results showed that mosquito control strategies offer potential long-term benefits to high elevation Hawaiian honeycreepers. However, combined strategies will likely be needed to preserve endemic birds at mid elevations. Given the delay required to research, develop, evaluate, and improve several of these currently untested conservation strategies we suggest that planning should begin expeditiously.
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Affiliation(s)
- Wei Liao
- Department of Forestry and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Carter T. Atkinson
- U. S. Geological Survey, Pacific Island Ecosystems Research Center, Hawai’i National Park, Hawai’i, United States of America
| | - Dennis A. LaPointe
- U. S. Geological Survey, Pacific Island Ecosystems Research Center, Hawai’i National Park, Hawai’i, United States of America
| | - Michael D. Samuel
- U. S. Geological Survey, Wisconsin Cooperative Wildlife Research Unit, University of Wisconsin, Madison, Wisconsin, United States of America
- * E-mail:
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22
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Gabrieli P, Scolari F. Delivery of Nucleic Acids through Embryo Microinjection in the Worldwide Agricultural Pest Insect, Ceratitis capitata. J Vis Exp 2016. [PMID: 27768087 DOI: 10.3791/54528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is a pest species with extremely high agricultural relevance. This is due to its reproductive behavior: females damage the external surface of fruits and vegetables when they lay eggs and the hatched larvae feed on their pulp. Wild C. capitata populations are traditionally controlled through insecticide spraying and/or eco-friendly approaches, the most successful being the Sterile Insect Technique (SIT). The SIT relies on mass-rearing, radiation-based sterilization and field release of males that retain their capacity to mate but are not able to generate fertile progeny. The advent and the subsequent rapid development of biotechnological tools, together with the availability of the medfly genome sequence, has greatly boosted our understanding of the biology of this species. This favored the proliferation of new strategies for genome manipulation, which can be applied to population control. In this context, embryo microinjection plays a dual role in expanding the toolbox for medfly control. The ability to interfere with the function of genes that regulate key biological processes, indeed, expands our understanding of the molecular machinery underlying medfly invasiveness. Furthermore, the ability to achieve germ-line transformation facilitates the production of multiple transgenic strains that can be tested for future field applications in novel SIT settings. Indeed, genetic manipulation can be used to confer desirable traits that can, for example, be used to monitor sterile male performance in the field, or that can result in early life-stage lethality. Here we describe a method to microinject nucleic acids into medfly embryos to achieve these two main goals.
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Affiliation(s)
- Paolo Gabrieli
- Department of Biology and Biotechnology, University of Pavia
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23
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Testing the causality between CYP9M10 and pyrethroid resistance using the TALEN and CRISPR/Cas9 technologies. Sci Rep 2016; 6:24652. [PMID: 27095599 PMCID: PMC4837413 DOI: 10.1038/srep24652] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/04/2016] [Indexed: 01/07/2023] Open
Abstract
Recently-emerging genome editing technologies have enabled targeted gene knockout experiments even in non-model insect species. For studies on insecticide resistance, genome editing technologies offer some advantages over the conventional reverse genetic technique, RNA interference, for testing causal relationships between genes of detoxifying enzymes and resistance phenotypes. There were relatively abundant evidences indicating that the overexpression of a cytochrome P450 gene CYP9M10 confers strong pyrethroid resistance in larvae of the southern house mosquito Culex quinquefasciatus. However, reverse genetic verification has not yet been obtained because of the technical difficulty of microinjection into larvae. Here, we tested two genome editing technologies, transcription activator-like effector nucleases (TALEN)s and clustered regularly interspaced short palindromic repeats (CRISPR/Cas9), to disrupt CYP9M10 in a resistant strain of C. quinquefasciatus. Additionally, we developed a novel, effective approach to construct a TALE using the chemical cleavage of phosphorothioate inter-nucleotide linkages in the level 1 assembly. Both TALEN and CRISPR/Cas9 induced frame-shifting mutations in one or all copies of CYP9M10 in a pyrethroid-resistant strain. A line fixed with a completely disrupted CYP9M10 haplotype showed more than 100-fold reduction in pyrethroid resistance in the larval stage.
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24
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Borovsky D, Sterner A, Powell CA. CLONING AND EXPRESSING TRYPSIN MODULATING OOSTATIC FACTOR IN Chlorella desiccata TO CONTROL MOSQUITO LARVAE. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2016; 91:17-36. [PMID: 26440910 DOI: 10.1002/arch.21306] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The insect peptide hormone trypsin modulating oostatic factor (TMOF), a decapeptide that is synthesized by the mosquito ovary and controls the translation of the gut's trypsin mRNA was cloned and expressed in the marine alga Chlorella desiccata. To express Aedes aegypti TMOF gene (tmfA) in C. desiccata cells, two plasmids (pYES2/TMOF and pYDB4-tmfA) were engineered with pKYLX71 DNA (5 Kb) carrying the cauliflower mosaic virus (CaMV) promoter 35S(2) and the kanamycin resistant gene (neo), as well as, a 8 Kb nitrate reductase gene (nit) from Chlorella vulgaris. Transforming C. desiccata with pYES2/TMOF and pYDB4-tmfA show that the engineered algal cells express TMOF (20 ± 4 μg ± SEM and 17 ± 3 μg ± SEM, respectively in 3 × 10(8) cells) and feeding the cells to mosquito larvae kill 75 and 60% of Ae. aegypti larvae in 4 days, respectively. Southern and Northern blots analyses show that tmfA integrated into the genome of C. desiccata by homologous recombination using the yeast 2 μ circle of replication and the nit in pYES2/TMOF and pYDB4-tmfA, respectively, and the transformed algal cells express tmfA transcript. Using these algal cells it will be possible in the future to control mosquito larvae in the marsh.
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Affiliation(s)
- Dov Borovsky
- USDA ARS, Subtropical Horticultural Laboratory, Ft. Pierce, Florida, USA
| | | | - Charles A Powell
- Citrus Research and Education Center, University of Florida-IFAS, Ft. Pierce, Florida, USA
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25
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Criscione F, O'Brochta DA, Reid W. Genetic technologies for disease vectors. CURRENT OPINION IN INSECT SCIENCE 2015; 10:90-97. [PMID: 29588019 DOI: 10.1016/j.cois.2015.04.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/17/2015] [Accepted: 04/20/2015] [Indexed: 06/08/2023]
Abstract
The first genetic technologies for insect vectors of disease were introduced 20 years ago. As of today there are 12 classes of genetic technologies used as functional genomic tools for insect vectors of important diseases. Although the applications of genetic technologies in insect disease vectors have been conducted primarily in mosquitoes, other insect systems could benefit from current technologies. While the various technological platforms are likely to function in diverse arthropods, the delivery of these technologies to cells and tissues of interest is the major technical constraint that limits their widespread adoption. Increased community resources of various types would enhance the adoption of these technologies and potentially eliminate technical limitations.
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Affiliation(s)
- Frank Criscione
- Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, 9600 Gudelsky Drive, Rockville, MD 20850, United States.
| | - David A O'Brochta
- Institute for Bioscience and Biotechnology Research, Department of Entomology, University of Maryland, College Park, 9600 Gudelsky Drive, Rockville, MD 20850, United States.
| | - William Reid
- Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, 9600 Gudelsky Drive, Rockville, MD 20850, United States.
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26
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Wilke ABB, Marrelli MT. Paratransgenesis: a promising new strategy for mosquito vector control. Parasit Vectors 2015; 8:342. [PMID: 26104575 PMCID: PMC4489152 DOI: 10.1186/s13071-015-0959-2] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 06/17/2015] [Indexed: 11/23/2022] Open
Abstract
The three main mosquito genera, Anopheles, Aedes and Culex, transmit respectively malaria, dengue and lymphatic filariasis. Current mosquito control strategies have proved unsuccessful, and there still is a substantial number of morbidity and mortality from these diseases. Genetic control methods have now arisen as promising alternative strategies, based on two approaches: the replacement of a vector population by disease-refractory mosquitoes and the release of mosquitoes carrying a lethal gene to suppress target populations. However, substantial hurdles and limitations need to be overcome if these methods are to be used successfully, the most significant being that a transgenic mosquito strain is required for every target species, making genetically modified mosquito strategies inviable when there are multiple vector mosquitoes in the same area. Genetically modified bacteria capable of colonizing a wide range of mosquito species may be a solution to this problem and another option for the control of these diseases. In the paratransgenic approach, symbiotic bacteria are genetically modified and reintroduced in mosquitoes, where they express effector molecules. For this approach to be used in practice, however, requires a better understanding of mosquito microbiota and that symbiotic bacteria and effector molecules be identified. Paratransgenesis could prove very useful in mosquito species that are inherently difficult to transform or in sibling species complexes. In this approach, a genetic modified bacteria can act by: (a) causing pathogenic effects in the host; (b) interfering with the host's reproduction; (c) reducing the vector's competence; and (d) interfering with oogenesis and embryogenesis. It is a much more flexible and adaptable approach than the use of genetically modified mosquitoes because effector molecules and symbiotic bacteria can be replaced if they do not achieve the desired result. Paratransgenesis may therefore become an important integrated pest management tool for mosquito control.
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Affiliation(s)
- André Barretto Bruno Wilke
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Av. Dr. Arnaldo 715, São Paulo, SP, CEP-01246-904, Brazil.
| | - Mauro Toledo Marrelli
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Av. Dr. Arnaldo 715, São Paulo, SP, CEP-01246-904, Brazil.
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27
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Reeves RG, Bryk J, Altrock PM, Denton JA, Reed FA. First steps towards underdominant genetic transformation of insect populations. PLoS One 2014; 9:e97557. [PMID: 24844466 PMCID: PMC4028297 DOI: 10.1371/journal.pone.0097557] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 04/08/2014] [Indexed: 11/18/2022] Open
Abstract
The idea of introducing genetic modifications into wild populations of insects to stop them from spreading diseases is more than 40 years old. Synthetic disease refractory genes have been successfully generated for mosquito vectors of dengue fever and human malaria. Equally important is the development of population transformation systems to drive and maintain disease refractory genes at high frequency in populations. We demonstrate an underdominant population transformation system in Drosophila melanogaster that has the property of being both spatially self-limiting and reversible to the original genetic state. Both population transformation and its reversal can be largely achieved within as few as 5 generations. The described genetic construct {Ud} is composed of two genes; (1) a UAS-RpL14.dsRNA targeting RNAi to a haploinsufficient gene RpL14 and (2) an RNAi insensitive RpL14 rescue. In this proof-of-principle system the UAS-RpL14.dsRNA knock-down gene is placed under the control of an Actin5c-GAL4 driver located on a different chromosome to the {Ud} insert. This configuration would not be effective in wild populations without incorporating the Actin5c-GAL4 driver as part of the {Ud} construct (or replacing the UAS promoter with an appropriate direct promoter). It is however anticipated that the approach that underlies this underdominant system could potentially be applied to a number of species.
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Affiliation(s)
- R. Guy Reeves
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, Plön, Germany
- * E-mail:
| | - Jarosław Bryk
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Philipp M. Altrock
- Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Jai A. Denton
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Floyd A. Reed
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, Plön, Germany
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28
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Wilke ABB, Scaife S, Alphey L, Marrelli MT. DsRed2 transient expression in Culex quinquefasciatus mosquitoes. Mem Inst Oswaldo Cruz 2013; 108:529-31. [PMID: 23828005 PMCID: PMC3970632 DOI: 10.1590/s0074-02762013000400023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 12/07/2012] [Indexed: 11/21/2022] Open
Abstract
Culex quinquefasciatus mosquitoes have been successfully genetically modified only once, despite the efforts of several laboratories to transform and establish a stable strain. We have developed a transient gene expression method, in Culex, that delivers plasmid DNA directly to the mosquito haemolymph and additional tissues. We were able to express DsRed2 fluorescent protein in adult Cx. quinquefasciatus mosquitoes by injecting plasmids directly into their thorax. The expression of DsRed2 in adult Cx. quinquefasciatus mosquitoes is an important stepping stone to genetic transformation and the potential use of new control strategies and genetic interactions.
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Affiliation(s)
- André Barretto Bruno Wilke
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, SP, Brasil.
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29
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Meredith JM, Underhill A, McArthur CC, Eggleston P. Next-generation site-directed transgenesis in the malaria vector mosquito Anopheles gambiae: self-docking strains expressing germline-specific phiC31 integrase. PLoS One 2013; 8:e59264. [PMID: 23516619 PMCID: PMC3596282 DOI: 10.1371/journal.pone.0059264] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 02/13/2013] [Indexed: 01/27/2023] Open
Abstract
Diseases transmitted by mosquitoes have a devastating impact on global health and the situation is complicated due to difficulties with both existing control measures and the impact of climate change. Genetically modified mosquitoes that are refractory to disease transmission are seen as having great potential in the delivery of novel control strategies. The Streptomyces phage phiC31 integrase system has been successfully adapted for site-directed transgene integration in a range of insects, thus overcoming many limitations due to size constraints and random integration associated with transposon-mediated transformation. Using this technology, we previously published the first site-directed transformation of Anopheles gambiae, the principal vector of human malaria. Mosquitoes were initially engineered to incorporate the phiC31 docking site at a defined genomic location. A second phase of genetic modification then achieved site-directed integration of an anti-malarial effector gene. In the current publication we report improved efficiency and utility of the phiC31 integrase system following the generation of Anopheles gambiae self-docking strains. Four independent strains, with docking sites at known locations on three different chromosome arms, were engineered to express integrase under control of the regulatory regions of the nanos gene from Anopheles gambiae. The resulting protein accumulates in the posterior oocyte to provide integrase activity at the site of germline development. Two self-docking strains, exhibiting significantly different levels of integrase expression, were assessed for site-directed transgene integration and found to demonstrate greatly improved survival and efficiency of transformation. In the fight against malaria, it is imperative to establish a broad repertoire of both anti-malarial effector genes and tissue-specific promoters to regulate their expression, enabling those offering maximum effect with minimum fitness cost to be identified. The improved technology we describe here will facilitate comparative studies of effector transgenes, allowing informed choices to be made that potentially lead to transmission blockade.
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Affiliation(s)
- Janet M. Meredith
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Keele, Staffordshire, United Kingdom
| | - Ann Underhill
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Keele, Staffordshire, United Kingdom
| | - Clare C. McArthur
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Keele, Staffordshire, United Kingdom
| | - Paul Eggleston
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Keele, Staffordshire, United Kingdom
- * E-mail:
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Abstract
The ability to introduce genetic constructs of choice into the genome of Anopheles mosquitoes provides a valuable tool to study the molecular interactions between the Plasmodium parasite and its insect host. In the long term, this technology could potentially offer new ways to control vector-borne diseases through the suppression of target mosquito populations or through the introgression of traits that preclude pathogen transmission. Here, we describe in detail protocols for the generation of transgenic Anopheles gambiae mosquitoes based on germ-line transformation using either modified transposable elements or the site-specific PhiC31 recombinase.
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Kim YJ, Hice RH, O'Brochta DA, Atkinson PW. DNA sequence requirements for hobo transposable element transposition in Drosophila melanogaster. Genetica 2011; 139:985-97. [PMID: 21805320 DOI: 10.1007/s10709-011-9600-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 07/18/2011] [Indexed: 01/08/2023]
Abstract
We have conducted a structure and functional analysis of the hobo transposable element of Drosophila melanogaster. A minimum of 141 bp of the left (L) end and 65 bp of the right (R) end of the hobo were shown to contain sequences sufficient for transposition. Both ends of hobo contain multiple copies of the motifs GGGTG and GTGGC and we show that the frequency of hobo transposition increases as a function of the copy number of these motifs. The R end of hobo contains a unique 12 bp internal inverted repeat that is identical to the hobo terminal inverted repeats. We show that this internal inverted repeat suppresses transposition activity in a hobo element containing an intact L end and only 475 bp of the R end. In addition to establishing cis-sequences requirements for transposition, we analyzed trans-sequence effects of the hobo transposase. We show a hobo transposase lacking the first 49 amino acids catalyzed hobo transposition at a higher frequency than the full-length transposase suggesting that, similar to the related Ac transposase, residues at the amino end of the transposase reduce transposition. Finally, we compared target site sequences of hobo with those of the related Hermes element and found both transposons have strong preferences for the same insertion sites.
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Affiliation(s)
- Yu Jung Kim
- Graduate Program in Department of Biochemistry and Molecular Biology, University of California, Riverside, CA 92521, USA
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Benedict M, Eckerstorfer M, Franz G, Gaugitsch H, Greiter A, Heissenberger A, Knols B, Kumschick S, Nentwig W, Rabitsch W. Defining Environment Risk Assessment Criteria for Genetically Modified Insects to be placed on the EU Market. ACTA ACUST UNITED AC 2010. [DOI: 10.2903/sp.efsa.2010.en-71] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Smith RC, Atkinson PW. Mobility properties of the Hermes transposable element in transgenic lines of Aedes aegypti. Genetica 2010; 139:7-22. [PMID: 20596755 PMCID: PMC3030943 DOI: 10.1007/s10709-010-9459-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Accepted: 04/09/2010] [Indexed: 11/29/2022]
Abstract
The Hermes transposable element has been used to genetically transform a wide range of insect species, including the mosquito, Aedes aegypti, a vector of several important human pathogens. Hermes integrations into the mosquito germline are characterized by the non-canonical integration of the transposon and flanking plasmid and, once integrated, Hermes is stable in the presence of its transposase. In an effort to improve the post-integration mobility of Hermes in the germline of Ae. aegypti, a transgenic helper Mos1 construct expressing Hermes transposase under the control of a testis-specific promoter was crossed to a separate transgenic strain containing a target Hermes transposon. In less than 1% of the approximately 1,500 progeny from jumpstarter lines analyzed, evidence of putative Hermes germline remobilizations were detected. These recovered transposition events occur through an aberrant mechanism and provide insight into the non-canonical cut-and-paste transposition of Hermes in the germ line of Ae. aegypti.
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Affiliation(s)
- Ryan C Smith
- Graduate Program in Cell, Molecular, Developmental Biology, University of California, Riverside, CA 92521, USA
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35
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Transgenesis and paratransgenesis to control insect-borne diseases: current status and future challenges. Parasitol Int 2009; 59:1-8. [PMID: 19819346 DOI: 10.1016/j.parint.2009.10.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2009] [Revised: 09/29/2009] [Accepted: 10/03/2009] [Indexed: 11/23/2022]
Abstract
Insect-borne diseases cause significant human morbidity and mortality. Current control and preventive methods against vector-borne diseases rely mainly on insecticides. The emergence of insecticide resistance in many disease vectors highlights the necessity to develop new strategies to control these insects. Vector transgenesis and paratransgenesis are novel strategies that aim at reducing insect vectorial capacity, or seek to eliminate transmission of pathogens such as Plasmodium sp., Trypanosoma sp., and Dengue virus currently being developed. Vector transgenesis relies on direct genetic manipulation of disease vectors making them incapable of functioning as vectors of a given pathogen. Paratransgenesis focuses on utilizing genetically modified insect symbionts to express molecules within the vector that are deleterious to pathogens they transmit. Despite the many successes achieved in developing such techniques in the last several years, many significant barriers remain and need to be overcome prior to any of these approaches become a reality. Here, we highlight the current status of these strategies, pointing out advantages and constraints, and also explore issues that need to be resolved before the establishment of transgenesis and paratransgenesis as tools to prevent vector-borne diseases.
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36
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Molecular genetic manipulation of vector mosquitoes. Cell Host Microbe 2008; 4:417-23. [PMID: 18996342 DOI: 10.1016/j.chom.2008.09.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 08/29/2008] [Accepted: 09/09/2008] [Indexed: 01/01/2023]
Abstract
Genetic strategies for reducing populations of vector mosquitoes or replacing them with those that are not able to transmit pathogens benefit greatly from molecular tools that allow gene manipulation and transgenesis. Mosquito genome sequences and associated EST (expressed sequence tags) databases enable large-scale investigations to provide new insights into evolutionary, biochemical, genetic, metabolic, and physiological pathways. Additionally, comparative genomics reveals the bases for evolutionary mechanisms with particular focus on specific interactions between vectors and pathogens. We discuss how this information may be exploited for the optimization of transgenes that interfere with the propagation and development of pathogens in their mosquito hosts.
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Juhn J, Marinotti O, Calvo E, James AA. Gene structure and expression of nanos (nos) and oskar (osk) orthologues of the vector mosquito, Culex quinquefasciatus. INSECT MOLECULAR BIOLOGY 2008; 17:545-52. [PMID: 18828840 PMCID: PMC3721150 DOI: 10.1111/j.1365-2583.2008.00823.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The products of the maternal-effect genes, nanos (nos) and oskar (osk), are important for the development of germ cells in insects. Furthermore, these genes have been proposed as candidates for donating functional DNA regulatory sequences for use in gene drive systems to control transmission of mosquito-borne pathogens. The nos and osk genes of the cosmopolitan vector mosquito, Culex quinquefasciatus, encode proteins with domains common to orthologues found in other mosquitoes. Expression analyses support the conclusion that the role of these genes is conserved generally among members of the nematocera. Hybridization in situ analyses reveal differences in mRNA distribution in early embryos in comparison with the cyclorraphan, Drosophila melanogaster, highlighting a possible feature in the divergence of the clades each insect represents.
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Affiliation(s)
- J Juhn
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
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38
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Ferguson HM, Ng'habi KR, Walder T, Kadungula D, Moore SJ, Lyimo I, Russell TL, Urassa H, Mshinda H, Killeen GF, Knols BG. Establishment of a large semi-field system for experimental study of African malaria vector ecology and control in Tanzania. Malar J 2008; 7:158. [PMID: 18715508 PMCID: PMC2543042 DOI: 10.1186/1475-2875-7-158] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Accepted: 08/20/2008] [Indexed: 01/08/2023] Open
Abstract
Background Medical entomologists increasingly recognize that the ability to make inferences between laboratory experiments of vector biology and epidemiological trends observed in the field is hindered by a conceptual and methodological gap occurring between these approaches which prevents hypothesis-driven empirical research from being conducted on relatively large and environmentally realistic scales. The development of Semi-Field Systems (SFS) has been proposed as the best mechanism for bridging this gap. Semi-field systems are defined as enclosed environments, ideally situated within the natural ecosystem of a target disease vector and exposed to ambient environmental conditions, in which all features necessary for its life cycle completion are present. Although the value of SFS as a research tool for malaria vector biology is gaining recognition, only a few such facilities exist worldwide and are relatively small in size (< 100 m2). Methods The establishment of a 625 m2 state-of-the-art SFS for large-scale experimentation on anopheline mosquito ecology and control within a rural area of southern Tanzania, where malaria transmission intensities are amongst the highest ever recorded, is described. Results A greenhouse frame with walls of mosquito netting and a polyethylene roof was mounted on a raised concrete platform at the Ifakara Health Institute. The interior of the SFS was divided into four separate work areas that have been set up for a variety of research activities including mass-rearing for African malaria vectors under natural conditions, high throughput evaluation of novel mosquito control and trapping techniques, short-term assays of host-seeking behaviour and olfaction, and longer-term experimental investigation of anopheline population dynamics and gene flow within a contained environment that simulates a local village domestic setting. Conclusion The SFS at Ifakara was completed and ready for use in under two years. Preliminary observations indicate that realistic and repeatable observations of anopheline behaviour are obtainable within the SFS, and that habitat and climatic features representative of field conditions can be simulated within it. As work begins in the SFS in Ifakara and others around the world, the major opportunities and challenges to the successful application of this tool for malaria vector research and control are discussed.
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Affiliation(s)
- Heather M Ferguson
- Division of Infection and Immunity, University of Glasgow, G128TA Glasgow, UK.
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Megy K, Hammond M, Lawson D, Bruggner RV, Birney E, Collins FH. Genomic resources for invertebrate vectors of human pathogens, and the role of VectorBase. INFECTION GENETICS AND EVOLUTION 2008; 9:308-13. [PMID: 18262474 DOI: 10.1016/j.meegid.2007.12.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Revised: 12/19/2007] [Accepted: 12/20/2007] [Indexed: 11/26/2022]
Abstract
High-throughput genome sequencing techniques have now reached vector biology with an emphasis on those species that are vectors of human pathogens. The first mosquito to be sequenced was Anopheles gambiae, the vector for Plasmodium parasites that cause malaria. Further mosquitoes have followed: Aedes aegypti (yellow fever and dengue fever vector) and Culex pipiens (lymphatic filariasis and West Nile fever). Species that are currently in sequencing include the body louse Pediculus humanus (Typhus vector), the triatomine Rhodnius prolixus (Chagas disease vector) and the tick Ixodes scapularis (Lyme disease vector). The motivations for sequencing vector genomes are to further understand vector biology, with an eye on developing new control strategies (for example novel chemical attractants or repellents) or understanding the limitations of current strategies (for example the mechanism of insecticide resistance); to analyse the mechanisms driving their evolution; and to perform an exhaustive analysis of the gene repertory. The proliferation of genomic data creates the need for efficient and accessible storage. We present VectorBase, a genomic resource centre that is both involved in the annotation of vector genomes and act as a portal for access to the genomic information (http://www.vectorbase.org).
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Affiliation(s)
- K Megy
- EMBL, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton CB10 1SD, UK.
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40
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Abstract
Research on gene expression in mosquitoes is motivated by both basic and applied interests. Studies of genes involved in hematophagy, reproduction, olfaction, and immune responses reveal an exquisite confluence of biological adaptations that result in these highly-successful life forms. The requirement of female mosquitoes for a bloodmeal for propagation has been exploited by a wide diversity of viral, protozoan and metazoan pathogens as part of their life cycles. Identifying genes involved in host-seeking, blood feeding and digestion, reproduction, insecticide resistance and susceptibility/refractoriness to pathogen development is expected to provide the bases for the development of novel methods to control mosquito-borne diseases. Advances in mosquito transgenesis technologies, the availability of whole genome sequence information, mass sequencing and analyses of transcriptomes and RNAi techniques will assist development of these tools as well as deepen the understanding of the underlying genetic components for biological phenomena characteristic of these insect species.
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Affiliation(s)
- Xiao-Guang Chen
- Department of Parasitology, School of Public Health and Tropical Medicine, Southern Medical University, Guang Zhou, GD 510515, People's Republic of China
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41
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Chen S, Li X. Molecular characterization of the first intact Transib transposon from Helicoverpa zea. Gene 2008; 408:51-63. [DOI: 10.1016/j.gene.2007.10.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 10/06/2007] [Accepted: 10/12/2007] [Indexed: 01/10/2023]
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Abraham EG, Cha SJ, Jacobs-Lorena M. Towards the genetic control of insect vectors: An overview. ENTOMOLOGICAL RESEARCH 2007; 37:213-220. [PMID: 25530773 PMCID: PMC4268783 DOI: 10.1111/j.1748-5967.2007.00117.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Insects are responsible for the transmission of major infectious diseases. Recent advances in insect genomics and transformation technology provide new strategies for the control of insect borne pathogen transmission and insect pest management. One such strategy is the genetic modification of insects with genes that block pathogen development. Another is to suppress insect populations by releasing either sterile males or males carrying female-specific dominant lethal genes into the environment. Although significant progress has been made in the laboratory, further research is needed to extend these approaches to the field. These insect control strategies offer several advantages over conventional insecticide-based strategies. However, the release of genetically modified insects into the environment should proceed with great caution, after ensuring its safety, and acceptance by the target populations.
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Affiliation(s)
- Eappen G Abraham
- Department of Molecular Microbiology and Immunology, John Hopkins Bloomberg School of Public Health and Johns Hopkins Malaria Research Institute, Baltimore, Maryland, USA
| | - Sung-Jae Cha
- Department of Molecular Microbiology and Immunology, John Hopkins Bloomberg School of Public Health and Johns Hopkins Malaria Research Institute, Baltimore, Maryland, USA
| | - Marcelo Jacobs-Lorena
- Department of Molecular Microbiology and Immunology, John Hopkins Bloomberg School of Public Health and Johns Hopkins Malaria Research Institute, Baltimore, Maryland, USA
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43
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Lobo NF, Clayton JR, Fraser MJ, Kafatos FC, Collins FH. High efficiency germ-line transformation of mosquitoes. Nat Protoc 2007; 1:1312-7. [PMID: 17406416 DOI: 10.1038/nprot.2006.221] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The ability to manipulate the mosquito genome through germ-line transformation provides us with a powerful tool for investigating gene structure and function. It is also a valuable method for the development of novel approaches to combating the spread of mosquito-vectored diseases. To date, germ-line transformation has been demonstrated in several mosquito species. Transgenes are introduced into pre-blastocyst mosquito embryos using microinjection techniques that take a few hours, and progeny are screened for the presence of a marker gene. The microinjection protocol presented here can be applied to most mosquitoes and contains several improvements over other published methods that increase the survival of injected embryos and, therefore, the number of transformants. Transgenic lines can be established in approximately 1 month using this technique.
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Affiliation(s)
- Neil F Lobo
- Center for Global Health and Infectious Diseases, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
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44
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Kawashima T, Osanai M, Futahashi R, Kojima T, Fujiwara H. A novel target-specific gene delivery system combining baculovirus and sequence-specific long interspersed nuclear elements. Virus Res 2007; 127:49-60. [PMID: 17498830 DOI: 10.1016/j.virusres.2007.03.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Revised: 03/16/2007] [Accepted: 03/17/2007] [Indexed: 11/26/2022]
Abstract
Transposable elements are valuable for somatic and germ-line transformation. However, long interspersed nuclear elements (LINEs) have not been used because of poor information on the transposition mechanism. We have developed a novel gene delivery system combining baculovirus AcNPV and two silkworm LINEs, SART1 and R1, which integrate into specific sequences of telomeric repeats and 28S ribosomal DNA, respectively. When two LINEs containing the enhanced green fluorescent protein gene recombined into AcNPV were infected into fifth instar larvae of the silkworm, we observed target-specific retrotransposition of LINEs at 72h post-infection, using polymerase chain reaction amplification and sequencing. Telomere- and 28S rDNA-specific transposition occurred in all nine tissues tested, including the ovary and testis. This is the first demonstration of site-specific gene delivery in living larvae. Insertion efficiencies were dependent on the virus titer for injection and the host strains of Bombyx mori. Using this system, we successfully detected the intergeneration transmission of retrotransposed sequences. In addition, AcNPV-mediated SART1 also transposed into telomere of another lepidopteran, Orgyia recens, suggesting that this system is useful for a wide variety of AcNPV-infectious insects. Site-specific gene delivery by virus-mediated LINE will be a potential gene therapy tool to avoid harmful unexpected insertions.
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Affiliation(s)
- Tomoko Kawashima
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Bioscience Bldg. 501, Kashiwa, Chiba 277-8562, Japan.
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Dieng H, Boots M, Tamori N, Higashihara J, Okada T, Kato K, Eshita Y. Some technical and ecological determinants of hatchability in Aedes albopictus, a potential candidate for transposon-mediated transgenesis. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2006; 22:382-9. [PMID: 17067035 DOI: 10.2987/8756-971x(2006)22[382:staedo]2.0.co;2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Fertility is a physiological process of great importance underlying the dynamics of mosquito populations. In transgenesis, it is a prerequisite for the production of subsequent generations and a crucial parameter for evaluating efficiency. Yet, ongoing success in mosquito vector transformation is being severely affected by low embryo survivability. In the prospect of overcoming this impediment, we investigated the darkening/hardening process of the chorion, the effects of some parameters required for transgenesis on hatch success, and erratic hatching in Aedes albopictus, a species that has not yet been targeted for transformation. The eggs from this species, when placed in a moistened environment while whitish, become dark and yet still remain soft approximately 2 h 10 min postoviposition. Those reared in a high moisture environment hatched at a high rate compared with their counterparts submitted to a drier environment. Submission of eggs to p-nitrophenyl-p'-guanidino-benzoate, a substance known to delay the darkening/delay process, resulted in a hatch rate lower than that from eggs soaked in distilled water, which suggests a negative impact on viability. Heat-shock treatment did not taint embryo viability. Overall, eggs displayed a tolerance to an hour of heat shock at 39 degrees C but still hatched at a considerable rate after a 1 hr exposure to 42 degrees C. Hatching was erratic, with a high rate of hatching on the initial flooding and lower rates of hatching on subsequent floodings, all of which resulted cumulatively in considerable hatch success. Our results should serve as a useful reference for the production of both transgenic and laboratory strains of floodwater Aedes mosquitoes.
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Affiliation(s)
- Hamady Dieng
- Department of Infectious Disease Control, Faculty of Medicine, Oita University, Hasamamachi, Japan
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46
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Beaty BJ. Control of arbovirus diseases: is the vector the weak link? ARCHIVES OF VIROLOGY. SUPPLEMENTUM 2006:73-88. [PMID: 16358423 DOI: 10.1007/3-211-29981-5_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Arthropod-borne virus (arbovirus) diseases (ABVDs) remain major threats to human health and well-being and, as an epidemiologic group, inflict an unacceptable health and economic burden on humans and animals, including livestock. The developed world has been fortunate to have escaped much of the burden that arboviruses and their arthropod vectors inflict on humans in disease endemic countries, but the introduction and rapid spread of West Nile virus in the Western Hemisphere demonstrated that we can no longer be complacent in the face of these emerging and resurging vector-borne diseases. Unfortunately, as the burdens and threats of ABVDs have increased, the U.S. and international public health capacity to address them has decreased. Vaccines are not available for most of these agents. Previously successful strategies to control ABVDs emphasized vector control, but source reduction and vector control strategies using pesticides have not been sustainable. New insights into vector biology and vector pathogen interactions, and the novel targets that likely will be forthcoming in the vector post-genomics era, provide new targets and opportunities for vector control and disease reduction programs. These findings and approaches must be incorporated into existing strategies if we are to control these important pathogens.
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Affiliation(s)
- B J Beaty
- Department of Microbiology, Immunology, and Pathology, Arthropod-Borne and Infectious Diseases Laboratory, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
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47
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Calvo E, Walter M, Adelman ZN, Jimenez A, Onal S, Marinotti O, James AA. Nanos (nos) genes of the vector mosquitoes, Anopheles gambiae, Anopheles stephensi and Aedes aegypti. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2005; 35:789-98. [PMID: 15894194 DOI: 10.1016/j.ibmb.2005.02.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/11/2005] [Indexed: 05/02/2023]
Abstract
A number of genetics-based strategies for the control of vector-borne diseases require the development of genetic drive systems for introgressing antipathogen effector genes into wild populations of insects. Modified transposons whose mobilization is controlled by the DNA elements of developmentally regulated genes offer a potential solution for introducing effector genes into mosquitoes. Such elements could exhibit sex-, stage- and species-specific transposition, thus mitigating some of the concerns associated with autonomous transposition. Hybridizations in situ show that the transcription products of the nanos orthologous genes of Anopheles gambiae (Anga nos), An. stephensi (Anst nos) and Aedes aegypti (Aeae nos) accumulate in developing oocytes in adult females and localize to the posterior pole in early embryos. These features make nos genes promising candidates for donating control sequences to modified transposons.
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Affiliation(s)
- Eric Calvo
- Department of Molecular Biology & Biochemistry, 3205 McGaugh Hall, University of California, Irvine, CA 92697-3900, USA
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48
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Allen ML, Christensen BM. Flight muscle-specific expression of act88F: GFP in transgenic Culex quinquefasciatus Say (Diptera: Culicidae). Parasitol Int 2004; 53:307-14. [PMID: 15464440 DOI: 10.1016/j.parint.2004.04.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2003] [Accepted: 04/14/2004] [Indexed: 11/21/2022]
Abstract
A strategy to engineer a strain of Culex mosquitoes refractory to filarial transmission is described. A requirement for success of the strategy is identification of a flight muscle-specific promoter that functions in the mosquito. A GFP marker gene under the control of the promoter region of the Drosophila melanogaster act88F gene was inserted into the genome of Culex quinquefasciatus. Transformation was confirmed by Mendelian genetics. Hybridization of a genomic Southern blot to a radiolabeled probe verified that the entire donor plasmid integrated into the mosquito genome. GFP expression in the transgenic mosquitoes was restricted to the flight muscles.
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Affiliation(s)
- Margaret L Allen
- Entomology Department, University of California, Riverside, CA 92521, USA.
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Arensburger P, Kim YJ, Orsetti J, Aluvihare C, O'Brochta DA, Atkinson PW. An active transposable element, Herves, from the African malaria mosquito Anopheles gambiae. Genetics 2004; 169:697-708. [PMID: 15545643 PMCID: PMC1449121 DOI: 10.1534/genetics.104.036145] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Transposable elements have proven to be invaluable tools for genetically manipulating a wide variety of plants, animals, and microbes. Some have suggested that they could be used to spread desirable genes, such as refractoriness to Plasmodium infection, through target populations of Anopheles gambiae, thereby disabling the mosquito's ability to transmit malaria. To achieve this, a transposon must remain mobile and intact after the initial introduction into the genome. Endogenous, active class II transposable elements from An. gambiae have not been exploited as gene vectors/drivers because none have been isolated. We report the discovery of an active class II transposable element, Herves, from the mosquito An. gambiae. Herves is a member of a distinct subfamily of hAT elements that includes the hopper-we element from Bactrocera dorsalis and B. cucurbitae. Herves was transpositionally active in mobility assays performed in Drosophila melanogaster S2 cells and developing embryos and was used as a germ-line transformation vector in D. melanogaster. Herves displays an altered target-site preference from the distantly related hAT elements, Hermes and hobo. Herves is also present in An. arabiensis and An. merus with copy numbers similar to that found in An. gambiae. Preliminary data from an East African population are consistent with the element being transpositionally active in mosquitoes.
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Affiliation(s)
- Peter Arensburger
- Department of Entomology, University of California, Riverside, California 92521-0314, USA
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Moreira LA, Wang J, Collins FH, Jacobs-Lorena M. Fitness of anopheline mosquitoes expressing transgenes that inhibit Plasmodium development. Genetics 2004; 166:1337-41. [PMID: 15082552 PMCID: PMC1470781 DOI: 10.1534/genetics.166.3.1337] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
One potential strategy for the control of malaria and other vector-borne diseases is the introduction into wild vector populations of genetic constructs that reduce vectorial capacity. An important caveat of this approach is that the genetic construct should have minimal fitness cost to the transformed vector. Previously, we produced transgenic Anopheles stephensi expressing either of two effector genes, a tetramer of the SM1 dodecapeptide or the phospholipase A2 gene (PLA2) from honeybee venom. Mosquitoes carrying either of these transgenes were impaired for Plasmodium berghei transmission. We have investigated the role of two effector genes for malaria parasite blockage in terms of the fitness imposed to the mosquito vector that expresses either molecule. By measuring mosquito survival, fecundity, fertility, and by running population cage experiments, we found that mosquitoes transformed with the SM1 construct showed no significant reduction in these fitness parameters relative to nontransgenic controls. The PLA2 transgenics, however, had reduced fitness that seemed to be independent of the insertion site of the transgene. We conclude that the fitness load imposed by refractory gene(s)-expressing mosquitoes depends on the effect of the transgenic protein produced in that mosquito. These results have important implications for implementation of malaria control via genetic modification of mosquitoes.
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Affiliation(s)
- Luciano A Moreira
- Department of Genetics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4955, USA
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