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Alphey L, Benedict M, Bellini R, Clark GG, Dame DA, Service MW, Dobson SL. Sterile-insect methods for control of mosquito-borne diseases: an analysis. Vector Borne Zoonotic Dis 2010; 10:295-311. [PMID: 19725763 PMCID: PMC2946175 DOI: 10.1089/vbz.2009.0014] [Citation(s) in RCA: 298] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Effective vector control, and more specifically mosquito control, is a complex and difficult problem, as illustrated by the continuing prevalence (and spread) of mosquito-transmitted diseases. The sterile insect technique and similar methods control certain agricultural insect pest populations in a species-specific, environmentally sound, and effective manner; there is increased interest in applying this approach to vector control. Such an approach, like all others in use and development, is not a one-size-fits-all solution, and will be more appropriate in some situations than others. In addition, the proposed release of pest insects, and more so genetically modified pest insects, is bound to raise questions in the general public and the scientific community as to such a method's efficacy, safety, and sustainability. This article attempts to address these concerns and indicate where sterile-insect methods are likely to be useful for vector control.
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Affiliation(s)
- Luke Alphey
- Oxitec Limited, Oxford, United
Kingdom
- Department of Zoology, University of Oxford, Oxford,
United Kingdom
| | - Mark Benedict
- Entomology Unit, International Atomic Energy Agency,
Vienna, Austria
| | - Romeo Bellini
- Centro Agricoltura Ambiente “G.Nicoli,”
Crevalcore, Italy
| | - Gary G. Clark
- Mosquito and Fly Research Unit, USDA-ARS-CMAVE,
Gainesville, Florida
| | | | - Mike W. Service
- Liverpool School of Tropical Medicine, Liverpool,
United Kingdom
| | - Stephen L. Dobson
- Department of Entomology, University of Kentucky,
Lexington, Kentucky
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152
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Fu G, Lees RS, Nimmo D, Aw D, Jin L, Gray P, Berendonk TU, White-Cooper H, Scaife S, Kim Phuc H, Marinotti O, Jasinskiene N, James AA, Alphey L. Female-specific flightless phenotype for mosquito control. Proc Natl Acad Sci U S A 2010; 107:4550-4. [PMID: 20176967 PMCID: PMC2826341 DOI: 10.1073/pnas.1000251107] [Citation(s) in RCA: 218] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dengue and dengue hemorrhagic fever are increasing public health problems with an estimated 50-100 million new infections each year. Aedes aegypti is the major vector of dengue viruses in its range and control of this mosquito would reduce significantly human morbidity and mortality. Present mosquito control methods are not sufficiently effective and new approaches are needed urgently. A "sterile-male-release" strategy based on the release of mosquitoes carrying a conditional dominant lethal gene is an attractive new control methodology. Transgenic strains of Aedes aegypti were engineered to have a repressible female-specific flightless phenotype using either two separate transgenes or a single transgene, based on the use of a female-specific indirect flight muscle promoter from the Aedes aegypti Actin-4 gene. These strains eliminate the need for sterilization by irradiation, permit male-only release ("genetic sexing"), and enable the release of eggs instead of adults. Furthermore, these strains are expected to facilitate area-wide control or elimination of dengue if adopted as part of an integrated pest management strategy.
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Affiliation(s)
- Guoliang Fu
- Oxitec Limited, 71 Milton Park, Oxford OX14 4RX, United Kingdom
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - Rosemary S. Lees
- Oxitec Limited, 71 Milton Park, Oxford OX14 4RX, United Kingdom
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - Derric Nimmo
- Oxitec Limited, 71 Milton Park, Oxford OX14 4RX, United Kingdom
| | - Diane Aw
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900; and
| | - Li Jin
- Oxitec Limited, 71 Milton Park, Oxford OX14 4RX, United Kingdom
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - Pam Gray
- Oxitec Limited, 71 Milton Park, Oxford OX14 4RX, United Kingdom
| | - Thomas U. Berendonk
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - Helen White-Cooper
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - Sarah Scaife
- Oxitec Limited, 71 Milton Park, Oxford OX14 4RX, United Kingdom
| | - Hoang Kim Phuc
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - Osvaldo Marinotti
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900; and
| | - Nijole Jasinskiene
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900; and
| | - Anthony A. James
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900; and
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697-3900
| | - Luke Alphey
- Oxitec Limited, 71 Milton Park, Oxford OX14 4RX, United Kingdom
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom
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153
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Papathanos PA, Bossin HC, Benedict MQ, Catteruccia F, Malcolm CA, Alphey L, Crisanti A. Sex separation strategies: past experience and new approaches. Malar J 2009; 8 Suppl 2:S5. [PMID: 19917075 PMCID: PMC2777327 DOI: 10.1186/1475-2875-8-s2-s5] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The success of the sterile insect technique (SIT) and other genetic strategies designed to eliminate large populations of insects relies on the efficient inundative releases of competitive, sterile males into the natural habitat of the target species. As released sterile females do not contribute to the sterility in the field population, systems for the efficient mass production and separation of males from females are needed. For vector species like mosquitoes, in which only females bite and transmit diseases, the thorough removal of females before release while leaving males competent to mate is a stringent prerequisite. Biological, genetic and transgenic approaches have been developed that permit efficient male-female separation for some species considered for SIT. However, most sex separation methods have drawbacks and many of these methods are not directly transferable to mosquitoes. Unlike genetic and transgenic systems, biological methods that rely on sexually dimorphic characters, such as size or development rate, are subject to natural variation, requiring regular adjustment and re-calibration of the sorting systems used. The yield can be improved with the optimization of rearing, but the scale of mass production places practical limits on what is achievable, resulting in a poor rearing to output ratio. High throughput separation is best achieved with scalable genetic or transgenic approaches.
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Affiliation(s)
- Philippos A Papathanos
- Imperial College London, Department of Biological Sciences, Imperial College Road, London SW7 2AZ, UK.
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154
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Abstract
The last few years have witnessed a considerable expansion in the number of tools available to perform molecular and genetic studies on the genome of Anopheles mosquitoes, the vectors of human malaria. As a consequence, knowledge of aspects of the biology of mosquitoes, such as immunity, reproduction and behaviour, that are relevant to their ability to transmit disease is rapidly increasing, and could be translated into concrete benefits for malaria control strategies. Amongst the most important scientific advances, the development of transgenic technologies for Anopheles mosquitoes provides a crucial opportunity to improve current vector control measures or design novel ones. In particular, the use of genetic modification of the mosquito genome could provide for a more effective deployment of the sterile insect technique (SIT) against vector populations in the field. Currently, SIT relies on the release of radiation sterilized males, which compete with wild males for mating with wild females. The induction of sterility in males through the genetic manipulation of the mosquito genome, already achieved in a number of other insect species, could eliminate the need for radiation and increase the efficiency of SIT-based strategies. This paper provides an overview of the mechanisms already in use for inducing sterility by transgenesis in Drosophila and other insects, and speculates on possible ways to apply similar approaches to Anopheles mosquitoes.
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Affiliation(s)
- Flaminia Catteruccia
- Imperial College London, Division of Cell and Molecular Biology, Imperial College Road, London SW7 2AZ, UK.
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155
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Site-specific recombination for the modification of transgenic strains of the Mediterranean fruit fly Ceratitis capitata. Proc Natl Acad Sci U S A 2009; 106:18171-6. [PMID: 19828439 DOI: 10.1073/pnas.0907264106] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Insect transgenesis is mainly based on the random genomic integration of DNA fragments embedded into non-autonomous transposable elements. Once a random insertion into a specific location of the genome has been identified as particularly useful with respect to transgene expression, the ability to make the insertion homozygous, and lack of fitness costs, it may be advantageous to use that location for further modification. Here we describe an efficient method for the modification of previously inserted transgenes by the use of the site-specific integration system from phage phiC31 in a tephritid pest species, the Mediterranean fruit fly Ceratitis capitata. First, suitable transgenic strains with randomly integrated attP landing sites within transposon-based vectors were identified by molecular and functional characterization. Second, donor plasmids containing an attB site, with additional markers, and transposon ends were integrated into attP sites by phiC31 integrase-mediated recombination. Third, transposase-encoding 'jumpstarter' strains were created and mated to transgenic strains resulting in the postintegrational excision of transposon ends, which left stably integrated transgene insertions that could not be remobilized. This three-step integration and stabilization system will allow the combination of several transgene-encoded advantageous traits at evaluated genomic positions to generate optimized strains for pest control that minimize environmental concerns.
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156
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Tigges M, Fussenegger M. Recent advances in mammalian synthetic biology-design of synthetic transgene control networks. Curr Opin Biotechnol 2009; 20:449-60. [PMID: 19762224 DOI: 10.1016/j.copbio.2009.07.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 07/30/2009] [Accepted: 07/31/2009] [Indexed: 10/20/2022]
Abstract
Capitalizing on an era of functional genomic research, systems biology offers a systematic quantitative analysis of existing biological systems thereby providing the molecular inventory of biological parts that are currently being used for rational synthesis and engineering of complex biological systems with novel and potentially useful functions-an emerging discipline known as synthetic biology. During the past decade synthetic biology has rapidly developed from simple control devices fine-tuning the activity of single genes and proteins to multi-gene/protein-based transcription and signaling networks providing new insight into global control and molecular reaction dynamics, thereby enabling the design of novel drug-synthesis pathways as well as genetic devices with unmatched biological functions. While pioneering synthetic devices have first been designed as test, toy, and teaser systems for use in prokaryotes and lower eukaryotes, first examples of a systematic assembly of synthetic gene networks in mammalian cells has sketched the full potential of synthetic biology: foster novel therapeutic opportunities in gene and cell-based therapies. Here we provide a concise overview on the latest advances in mammalian synthetic biology.
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Affiliation(s)
- Marcel Tigges
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, Basel CH-4058, Switzerland
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157
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Guerrero FD, Dowd SE, Djikeng A, Wiley G, Macmil S, Saldivar L, Najar F, Roe BA. A database of expressed genes from Cochliomyia hominivorax (Diptera: Calliphoridae). JOURNAL OF MEDICAL ENTOMOLOGY 2009; 46:1109-1116. [PMID: 19769042 DOI: 10.1603/033.046.0518] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We used an expressed sequence tag and 454 pyrosequencing approach to initiate a study of the genome of the screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae). Two normalized cDNA libraries were constructed from RNA isolated from embryos and second instar larvae from the Panama 95 strain. Approximately 5,400 clones from each library were sequenced from both the 5' and 3' directions using the Sanger method. In addition, double-stranded cDNA was prepared from random-primed polyA RNA purified from embryos, second-instar larvae, adult males, and adult females. These four cDNA samples were used for 454 pyrosequencing that produced approximately 300,000 independent sequences. Sequences were assembled into a database of assembled contigs and singletons and used to search public protein databases and annotate the sequences. The full database consists of 6,076 contigs and 58,221 singletons assembled from both the traditional expressed sequence tag (EST) and 454 sequences. Annotation of the data led to the identification of several gene coding regions with possible roles in sex determination in the screwworm. This database will facilitate the design of microarray and other experiments to study screwworm gene expression on a larger scale than previously possible.
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Affiliation(s)
- F D Guerrero
- USDA-ARS, Knipling-Bushland U.S. Livestock Insects Research Laboratory; 2700 Fredericksburg Rd., Kerrville, TX 78028 , USA.
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158
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Weber W, Fussenegger M. The impact of synthetic biology on drug discovery. Drug Discov Today 2009; 14:956-63. [PMID: 19580884 PMCID: PMC7108258 DOI: 10.1016/j.drudis.2009.06.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 06/23/2009] [Accepted: 06/25/2009] [Indexed: 11/30/2022]
Abstract
The emergence of synthetic biology is holding great hopes for providing solutions to the unmet needs of humankind. This review article describes how synthetic biology can deliver on this promise in the field of drug discovery by providing novel opportunities throughout the entire drug discovery process. Synthetic biology tools enable disease mechanisms and target identification to be elucidated and also provide avenues to discover small chemotherapeutic molecules or design novel biopharmaceuticals. Furthermore, synthetic biologists can design cost-effective microbial production processes for complex natural products, which could help overcome global drug shortages. These impressive advances have been achieved in only a few years, and are an indicator for the potential of synthetic biology.
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Affiliation(s)
- Wilfried Weber
- Centre for Biological Signalling Studies (bioss), Albert-Ludwigs-Universität Freiburg, Engesserstrasse 4b, D-79108 Freiburg, Germany
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159
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Sexual development in Lucilia cuprina (Diptera, Calliphoridae) is controlled by the transformer gene. Genetics 2009; 182:785-98. [PMID: 19433631 DOI: 10.1534/genetics.109.100982] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Insects use an amazing variety of genetic systems to control sexual development. A Y-linked male determining gene (M) controls sex in the Australian sheep blowfly Lucilia cuprina, an important pest insect. In this study, we isolated the L. cuprina transformer (Lctra) and transformer2 (Lctra2) genes, which are potential targets of M. The LCTRA and LCTRA2 proteins are significantly more similar to homologs from tephritid insects than Drosophila. The Lctra transcript is alternatively spliced such that only females make a full-length protein and the presence of six TRA/TRA2 binding sites in the female first intron suggest that Lctra splicing is autoregulated as in tephritids. LCTRA is essential for female development as RNAi knockdown of Lctra mRNA leads to the development of male genitalia in XX adults. Analysis of Lctra expression during development shows that early and midstage male and female embryos express the female form of Lctra and males express only the male form by the first instar larval stage. Our results suggest that an autoregulatory loop sustains female development and that expression of M inhibits Lctra autoregulation, switching its splicing to the male form. The conservation of tra function and regulation in a Calliphorid insect shows that this sex determination system is not confined to Tephritidae. Isolation of these genes is an important step toward the development of a strain of L. cuprina suitable for a genetic control program.
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160
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161
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Weber W, Fussenegger M. Engineering of Synthetic Mammalian Gene Networks. ACTA ACUST UNITED AC 2009; 16:287-97. [DOI: 10.1016/j.chembiol.2009.02.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 01/28/2009] [Accepted: 02/03/2009] [Indexed: 12/15/2022]
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162
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Guerrero FD, Dowd SE, Sun Y, Saldivar L, Wiley GB, Macmil SL, Najar F, Roe BA, Foil LD. Microarray analysis of female- and larval-specific gene expression in the horn fly (Diptera: Muscidae). JOURNAL OF MEDICAL ENTOMOLOGY 2009; 46:257-270. [PMID: 19351076 DOI: 10.1603/033.046.0210] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The horn fly, Haematobia irritans L., is an obligate blood-feeding parasite of cattle, and control of this pest is a continuing problem because the fly is becoming resistant to pesticides. Dominant conditional lethal gene systems are being studied as population control technologies against agricultural pests. One of the components of these systems is a female-specific gene promoter that drives expression of a lethality-inducing gene. To identify candidate genes to supply this promoter, microarrays were designed from a horn fly expressed sequence tag (EST) database and probed to identify female-specific and larval-specific gene expression. Analysis of dye swap experiments found 432 and 417 transcripts whose expression levels were higher or lower in adult female flies, respectively, compared with adult male flies. Additionally, 419 and 871 transcripts were identified whose expression levels were higher or lower in first-instar larvae compared with adult flies, respectively. Three transcripts were expressed more highly in adult females flies compared with adult males and also higher in the first-instar larval lifestage compared with adult flies. One of these transcripts, a putative nanos ortholog, has a high female-to-male expression ratio, a moderate expression level in first-instar larvae, and has been well characterized in Drosophila. melanogaster (Meigen). In conclusion, we used microarray technology, verified by reverse transcriptase-polymerase chain reaction and massively parallel pyrosequencing, to study life stage- and sex-specific gene expression in the horn fly and identified three gene candidates for detailed evaluation as a gene promoter source for the development of a female-specific conditional lethality system.
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Affiliation(s)
- Felix D Guerrero
- USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory, 2700 Fredericksburg Rd., Kerrville, TX 78028, USA.
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163
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Schetelig MF, Caceres C, Zacharopoulou A, Franz G, Wimmer EA. Conditional embryonic lethality to improve the sterile insect technique in Ceratitis capitata (Diptera: Tephritidae). BMC Biol 2009; 7:4. [PMID: 19173707 PMCID: PMC2662800 DOI: 10.1186/1741-7007-7-4] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Accepted: 01/27/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The sterile insect technique (SIT) is an environment-friendly method used in area-wide pest management of the Mediterranean fruit fly Ceratitis capitata (Wiedemann; Diptera: Tephritidae). Ionizing radiation used to generate reproductive sterility in the mass-reared populations before release leads to reduction of competitiveness. RESULTS Here, we present a first alternative reproductive sterility system for medfly based on transgenic embryonic lethality. This system is dependent on newly isolated medfly promoter/enhancer elements of cellularization-specifically-expressed genes. These elements act differently in expression strength and their ability to drive lethal effector gene activation. Moreover, position effects strongly influence the efficiency of the system. Out of 60 combinations of driver and effector construct integrations, several lines resulted in larval and pupal lethality with one line showing complete embryonic lethality. This line was highly competitive to wildtype medfly in laboratory and field cage tests. CONCLUSION The high competitiveness of the transgenic lines and the achieved 100% embryonic lethality causing reproductive sterility without the need of irradiation can improve the efficacy of operational medfly SIT programs.
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Affiliation(s)
- Marc F Schetelig
- Department of Developmental Biology, Göttingen Center for Molecular Biosciences, Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, Georg-August-University Göttingen, GZMB, Ernst-Caspari-Haus, Göttingen, Germany.
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164
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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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165
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Genomics of reproduction in nematodes: prospects for parasite intervention? Trends Parasitol 2008; 24:89-95. [PMID: 18182326 DOI: 10.1016/j.pt.2007.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2007] [Revised: 10/11/2007] [Accepted: 12/06/2007] [Indexed: 11/21/2022]
Abstract
Understanding reproductive processes in parasitic nematodes has the potential to lead to the informed design of new anthelmintics and control strategies. Little is known, however, about the molecular mechanisms underlying sex determination, gametogenesis and reproductive physiology for most parasitic nematodes. Together with comparative analyses of data for the free-living nematode Caenorhabditis elegans, molecular investigations are beginning to provide insights into the processes involved in reproduction and development in parasitic nematodes. Here, we review recent developments, focusing on technological aspects and on molecules associated with sex-specific differences in adult nematodes.
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166
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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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167
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Condon KC, Condon GC, Dafa'alla TH, Fu G, Phillips CE, Jin L, Gong P, Alphey L. Genetic sexing through the use of Y-linked transgenes. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2007; 37:1168-1176. [PMID: 17916503 DOI: 10.1016/j.ibmb.2007.07.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2007] [Revised: 07/03/2007] [Accepted: 07/06/2007] [Indexed: 05/25/2023]
Abstract
Sterile insect technique (SIT)-based pest control programs rely on the mass release of sterile insects to reduce the wild target population. In many cases, it is desirable to release only males. Sterile females may cause damage, e.g., disease transmission by mosquitoes or crop damage via oviposition by the Mediterranean fruit fly (Medfly). Also, sterile females may decrease the effectiveness of released males by distracting them from seeking out wild females. To eliminate females from the release population, a suitable sexual dimorphism is required. For several pest species, genetic sexing strains have been constructed in which such a dimorphism has been induced by genetics. Classical strains were based on the translocation to the Y chromosome of a selectable marker, which is therefore expressed only in males. Recently, several prototype strains have been constructed using sex-specific expression of markers or conditional lethal genes from autosomal insertions of transgenes. Here, we describe a novel genetic sexing strategy based on the use of Y-linked transgenes expressing fluorescent proteins. We demonstrate the feasibility of this strategy in a major pest species, Ceratitis capitata (Wiedemann), and discuss the advantages and disadvantages relative to other genetic sexing methods and potential applicability to other species.
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Affiliation(s)
- Kirsty C Condon
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
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168
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Condon KC, Condon GC, Dafa'alla TH, Forrester OT, Phillips CE, Scaife S, Alphey L. Germ-line transformation of the Mexican fruit fly. INSECT MOLECULAR BIOLOGY 2007; 16:573-80. [PMID: 17894556 DOI: 10.1111/j.1365-2583.2007.00752.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Germ-line transformation of a major agricultural pest, the Mexican fruit fly (Anastrepha ludens Loew, Mexfly), was achieved using composite piggyBac transposable elements marked with green, yellow and red fluorescent proteins (CopGreen, PhiYFP and J-Red). We also investigated the possibility of generating transposon-free insertions, in order to address potential concerns relating to proposed field use of transgenic Mexfly. We describe a highly efficient method for transforming Mexfly, compare efficiency of piggyBac terminal sequences for transformation and also describe the derivation of a transposon-free insertion line. The development of an efficient transformation system for Mexfly holds great promise for improved applications of the sterile insect technique, a major component of the present control measures for this economically important pest species.
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Affiliation(s)
- K C Condon
- Department of Zoology, University of Oxford, South Parks Road, Oxford, UK
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