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Pfeifer TA, Ring M, Grigliatti TA. Identification and analysis of Lydia, a LTR retrotransposon from Lymantria dispar. INSECT MOLECULAR BIOLOGY 2000; 9:349-356. [PMID: 10971712 DOI: 10.1046/j.1365-2583.2000.00196.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Degenerative PCR primers to conserved amino acid motifs were used to identify an LTR retrotransposon from Lymantria dispar. The isolated retrotransposon, Lydia, is 6655 base pairs (bp) in length and contains perfect 300 bp terminal repeats. The identified gag and pol related ORFs have a high degree of similarity to the corresponding regions of the retrotransposon Ted from Trichoplusia ni, although several reading frameshifts and missense mutations are evident. The high degree of similarity between Lydia and Ted LTRs lends support for a family of lepidopteran retrotransposons. Southern blot analysis of individuals from two geographically distinct gypsy moth populations demonstrates that Lydia is found in both populations and the position of this element within the genome of these isolated populations is variable.
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Affiliation(s)
- T A Pfeifer
- Department of Zoology, University of British Columbia, Vancouver, Canada
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52
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Kokoza V, Ahmed A, Cho WL, Jasinskiene N, James AA, Raikhel A. Engineering blood meal-activated systemic immunity in the yellow fever mosquito, Aedes aegypti. Proc Natl Acad Sci U S A 2000; 97:9144-9. [PMID: 10908672 PMCID: PMC16836 DOI: 10.1073/pnas.160258197] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Progress in molecular genetics makes possible the development of alternative disease control strategies that target the competence of mosquitoes to transmit pathogens. We tested the regulatory region of the vitellogenin (Vg) gene of Aedes aegypti for its ability to express potential antipathogen factors in transgenic mosquitoes. Hermes-mediated transformation was used to integrate a 2.1-kb Vg-promoter fragment driving the expression of the Defensin A (DefA) coding region, one of the major insect immune factors. PCR amplification of genomic DNA and Southern blot analyses, carried out through the ninth generation, showed that the Vg-DefA transgene insertion was stable. The Vg-DefA transgene was strongly activated in the fat body by a blood meal. The mRNA levels reached a maximum at 24-h postblood meal, corresponding to the peak expression time of the endogenous Vg gene. High levels of transgenic defensin were accumulated in the hemolymph of bloodfed female mosquitoes, persisting for 20-22 days after a single blood feeding. Purified transgenic defensin showed antibacterial activity comparable to that of defensin isolated from bacterially challenged control mosquitoes. Thus, we have been able to engineer the genetically stable transgenic mosquito with an element of systemic immunity, which is activated through the blood meal-triggered cascade rather than by infection. This work represents a significant step toward the development of molecular genetic approaches to the control of vector competence in pathogen transmission.
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Affiliation(s)
- V Kokoza
- Department of Entomology and Program in Genetics, Michigan State University, East Lansing, MI 48824, USA
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53
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Peloquin JJ, Thibault ST, Staten R, Miller TA. Germ-line transformation of pink bollworm (Lepidoptera: gelechiidae) mediated by the piggyBac transposable element. INSECT MOLECULAR BIOLOGY 2000; 9:323-333. [PMID: 10886417 DOI: 10.1046/j.1365-2583.2000.00194.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The pink bollworm, Pectinophora gossypiella, is a world-wide pest of cultivated cotton. In certain growing regions populations are suppressed by a sterile release strategy. Efforts to improve the sterile insect technique as well as our understanding of lepidopteran biology could benefit greatly from a germ-line transformation system. We report transformation of pink bollworm with a piggyBac transposable element carrying the enhanced green flourescent protein (EGFP) marker gene. This vector-marker system resulted in recovery of transgenics at a rate of approximately 3.5%. Integration of the transforming construct that was typical of piggyBac was demonstrated by Southern analysis and sequence determination of transposon flanks. Expression of the EGFP marker was visualized by fluorescent microscopy and Western Blot analysis. Maintenance of transformed strains indicates that the transgene segregates in a Mendelian fashion and has been stable over fourteen generations to date.
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Affiliation(s)
- J J Peloquin
- Department of Entomology, UC Riverside, Riverside, CA,
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Shimizu K, Kamba M, Sonobe H, Kanda T, Klinakis AG, Savakis C, Tamura T. Extrachromosomal transposition of the transposable element Minos occurs in embryos of the silkworm Bombyx mori. INSECT MOLECULAR BIOLOGY 2000; 9:277-281. [PMID: 10886411 DOI: 10.1046/j.1365-2583.2000.00182.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To assess the ability of the transposable element Minos to act as a vector for genetic manipulation of the silkworm Bombyx mori, an extrachromosomal transposition assay based on three plasmids was performed. The three plasmids - helper, donor and target - were co-injected into preblastoderm embryos. Low molecular weight DNA was extracted from the embryos at the stage of blastokinesis and used to transform Escherichia coli. High frequency of transposition was observed in the presence of a helper plasmid possessing an intronless Minos transposase gene, whereas transposition did not occur in the presence of a helper plasmid with the intron-bearing transposase gene. Sequence analysis of the insertion sites showed that Minos always inserts into a TA dinucleotide. Although the insertions are distributed throughout the target gene, there was a preference for certain insertion sites. However, no consensus could be identified in the sequence flanking the target site. The results strongly suggest that the transposable element Minos has the potential to be used as a vector in the silkworm and probably in other lepidopteran insects.
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Affiliation(s)
- K Shimizu
- Department of Biological Science, Konan University, Kobe, Japan
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Wang W, Swevers L, Iatrou K. Mariner (Mos1) transposase and genomic integration of foreign gene sequences in Bombyx mori cells. INSECT MOLECULAR BIOLOGY 2000; 9:145-155. [PMID: 10762422 DOI: 10.1046/j.1365-2583.2000.00172.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Widespread occurrence in insects and the capacity to transpose in the absence of host-derived factors means that mariner-like elements are considered to be attractive candidates for the development of a universal insect genetic transformation system. Here we show that the Mos1 mariner element of Drosophila mauritiana is capable of mediating excision and transposition events in a silkmoth (Bombyx mori) derived tissue culture cell line (Bm5 cells). Plasmid rescue assays, in combination with Southern hybridization and polymerase chain reaction (PCR) analyses, confirm that the Mos1 transposase can mediate excision of DNA sequences, inserted between terminally repeated sequences recognized by the transposase, and integration into the chromosomal DNA of the Bm5 cells. In addition to chromosomal integration events, inter- and intraplasmid transposition and target element excision events were also detected. Approximately 50% of the plasmids recovered from plasmid rescue assays were found to contain the 'signature' of Mos1-specific excision and/or integration events, indicating that the mariner transposase functions efficiently in the Bombyx cells. Because mariner-induced excision and integration events are strictly dependent on the presence of a co-transfected Mos1 transposase expression vector, it is clear that the multiple copies of endogenous mariner-like elements (Bmmar1) that exist in the Bombyx genome are neither functional nor do they interfere with the efficiency of the transposition process. Thus, the Mos1 element and, probably, mariner elements, in general, hold great promise for the development of genetic transformation systems for lepidopteran insects.
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Affiliation(s)
- W Wang
- Department of Biochemistry, University of Calgary, Canada
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56
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Abstract
Mosquito-borne diseases are responsible for significant human morbidity and mortality throughout the world. Efforts to control mosquito-borne diseases have been impeded, in part, by the development of drug-resistant parasites, insecticide-resistant mosquitoes, and environmental concerns over the application of insecticides. Therefore, there is a need to develop novel disease control strategies that can complement or replace existing control methods. One such strategy is to generate pathogen-resistant mosquitoes from those that are susceptible. To this end, efforts have focused on isolating and characterizing genes that influence mosquito vector competence. It has been known for over 70 years that there is a genetic basis for the susceptibility of mosquitoes to parasites, but until the advent of powerful molecular biological tools and protocols, it was difficult to assess the interactions of pathogens with their host tissues within the mosquito at a molecular level. Moreover, it has been only recently that the molecular mechanisms responsible for pathogen destruction, such as melanotic encapsulation and immune peptide production, have been investigated. The molecular characterization of genes that influence vector competence is becoming routine, and with the development of the Sindbis virus transducing system, potential antipathogen genes now can be introduced into the mosquito and their effect on parasite development can be assessed in vivo. With the recent successes in the field of mosquito germ line transformation, it seems likely that the generation of a pathogen-resistant mosquito population from a susceptible population soon will become a reality.
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Affiliation(s)
- B T Beerntsen
- Department of Molecular Biology & Biochemistry, University of California, Irvine, California 92697, USA
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57
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Tamura T, Thibert C, Royer C, Kanda T, Abraham E, Kamba M, Komoto N, Thomas JL, Mauchamp B, Chavancy G, Shirk P, Fraser M, Prudhomme JC, Couble P, Toshiki T, Chantal T, Corinne R, Toshio K, Eappen A, Mari K, Natuo K, Jean-Luc T, Bernard M, Gérard C, Paul S, Malcolm F, Jean-Claude P, Pierre C. Germline transformation of the silkworm Bombyx mori L. using a piggyBac transposon-derived vector. Nat Biotechnol 2000; 18:81-4. [PMID: 10625397 DOI: 10.1038/71978] [Citation(s) in RCA: 502] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have developed a system for stable germline transformation in the silkworm Bombyx mori L. using piggyBac, a transposon discovered in the lepidopteran Trichoplusia ni. The transformation constructs consist of the piggyBac inverted terminal repeats flanking a fusion of the B. mori cytoplasmic actin gene BmA3 promoter and the green fluorescent protein (GFP). A nonautonomous helper plasmid encodes the piggyBac transposase. The reporter gene construct was coinjected into preblastoderm eggs of two strains of B. mori. Approximately 2% of the individuals in the G1 broods expressed GFP. DNA analyses of GFP-positive G1 silkworms revealed that multiple independent insertions occurred frequently. The transgene was stably transferred to the next generation through normal Mendelian inheritance. The presence of the inverted terminal repeats of piggyBac and the characteristic TTAA sequence at the borders of all the analyzed inserts confirmed that transformation resulted from precise transposition events. This efficient method of stable gene transfer in a lepidopteran insect opens the way for promising basic research and biotechnological applications.
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Affiliation(s)
- T Tamura
- National Institute of Sericultural and Entomological Science, Tsukuba, Ibaraki 305-8634, Japan
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58
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Braquart C, Royer V, Bouhin H. DEC: a new miniature inverted-repeat transposable element from the genome of the beetle Tenebrio molitor. INSECT MOLECULAR BIOLOGY 1999; 8:571-574. [PMID: 10620054 DOI: 10.1046/j.1365-2583.1999.00144.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In this paper we describe a novel family of miniature inverted-repeat transposable elements (MITEs), named DEC, isolated from the genome of the beetle Tenebrio molitor. These elements are highly reiterated and their number is estimated to be around 3500 per haploid genome. Two of them have been isolated and the two sequences are 84% identical. Like other MITEs, they are characterized by their small size, their A + T richness, the presence of terminal inverted repeats and the absence of open reading frames. These data suggest that MITEs are probably widely distributed in arthropods.
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Affiliation(s)
- C Braquart
- UMR CNRS 5548, 'Développement et communication chimique', Faculté des Sciences, Dijon, France
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60
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Handler AM, Harrell RA. Germline transformation of Drosophila melanogaster with the piggyBac transposon vector. INSECT MOLECULAR BIOLOGY 1999; 8:449-457. [PMID: 10634970 DOI: 10.1046/j.1365-2583.1999.00139.x] [Citation(s) in RCA: 207] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Germline transformation of Drosophila melanogaster was attempted with the piggyBac gene-transfer system from the cabbage looper moth, Trichoplusia ni. Using a self-regulated transposase helper and a white marked vector, a transformation frequency of 1-3% per fertile G0 was obtained, similar to that previously achieved in the medfly. Use of an hsp70-regulated helper increased this frequency more than eight-fold. Transformation with a vector marked with white and green fluorescent protein (GFP) under polyubiquitin-nuclear localizing sequence regulation yielded seventy G1 transformants which all expressed GFP, but only twenty-seven of these expressed eye pigmentation that would have allowed their selection based on white+ expression. PiggyBac transformation in two distantly related dipteran species and efficient expression of the gfp marker supports the potential use of this system in other dipterans, and perhaps insects in general.
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Affiliation(s)
- A M Handler
- Center for Medical, Agricultural, and Veterinary Entomology, US Department of Agriculture, Gainesville, FL 32608, USA.
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61
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Yamao M, Katayama N, Nakazawa H, Yamakawa M, Hayashi Y, Hara S, Kamei K, Mori H. Gene targeting in the silkworm by use of a baculovirus. Genes Dev 1999; 13:511-6. [PMID: 10072379 PMCID: PMC316505 DOI: 10.1101/gad.13.5.511] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The Bombyx mori fibroin light (L)-chain gene was cloned and the green fluorescent protein (GFP) gene inserted into exon 7. The chimeric L-chain-GFP gene was used to replace the polyhedrin gene of Autographa californica nucleopolyhedrovirus (AcNPV). This recombinant virus was used to target the L-chain-GFP gene to the L-chain region of the silkworm genome. Female moths were infected with the recombinant virus and then mated with normal male moths. Genomic DNA from their progenies was screened for the desired targeting event. This analysis showed that the chimeric gene had integrated into the L-chain gene on the genome by homologous recombination and was stably transmitted through generations. The chimeric gene was expressed in the posterior silk gland, and the gene product was spun into the cocoon layer.
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Affiliation(s)
- M Yamao
- Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto, Japan 606-8585
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62
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Abstract
Stable transformed insect cell lines have been used for producing many highly processed heterologous proteins. Current research has focused on development of new expression and selection systems, and enhancement of vector stability. Defining the variation of modification and processing capabilities between cell lines will further enhance complex protein production from insect cells.
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Affiliation(s)
- T A Pfeifer
- Department of Zoology, University of British Columbia, Vancouver, Canada.
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63
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Handler AM, McCombs SD, Fraser MJ, Saul SH. The lepidopteran transposon vector, piggyBac, mediates germ-line transformation in the Mediterranean fruit fly. Proc Natl Acad Sci U S A 1998; 95:7520-5. [PMID: 9636182 PMCID: PMC22671 DOI: 10.1073/pnas.95.13.7520] [Citation(s) in RCA: 170] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/1997] [Accepted: 04/21/1998] [Indexed: 02/07/2023] Open
Abstract
The piggyBac (IFP2) short inverted terminal repeat transposable element from the cabbage looper Trichoplusia ni was tested for gene transfer vector function as part of a bipartite vector-helper system in the Mediterranean fruit fly Ceratitis capitata. A piggyBac vector marked with the medfly white gene was tested with a normally regulated piggyBac transposase helper at two different concentrations in a white eye host strain. Both experiments yielded transformants at an approximate frequency of 3-5%, with a total of six lines isolated having pigmented eyes with various levels of coloration. G1 transformant siblings from each line shared at least one common integration, with several sublines having an additional second integration. For the first transformant line isolated, two integrations were determined to be stable for 15 generations. For five of the lines, a piggyBac-mediated transposition was verified by sequencing the insertion site junctions isolated by inverse PCR that identified a characteristic piggyBac TTAA target site duplication. The efficient and stable transformation of the medfly with a lepidopteran vector represents transposon function over a relatively large evolutionary distance and suggests that the piggyBac system will be functional in a broad range of insects.
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Affiliation(s)
- A M Handler
- Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, U.S. Department of Agriculture, Gainesville, FL, 32608, USA.
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Besansky NJ, Mukabayire O, Benedict MQ, Rafferty CS, Hamm DM, Mcnitt L. The Anopheles gambiae tryptophan oxygenase gene expressed from a baculovirus promoter complements Drosophila melanogaster vermilion. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 1997; 27:803-805. [PMID: 9443379 DOI: 10.1016/s0965-1748(97)00040-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
An Anopheles gambiae cDNA encoding tryptophan oxygenase was placed under the control of the constitutive baculovirus promoter, ie-1. The chimeric construct, expressed transiently in vermilion (tryptophan oxygenase) mutants of Drosophila melanogaster, partially rescued adult eye color. The successful genetic complementation by this construct demonstrated both the proper function of the tryptophan oxygenase product and the effectiveness of the ie-1 promoter in directing expression of foreign genes in live insects. The functionality of An. gambiae tryptophan oxygenase in a higher fly fulfils predictions based on its structural conservation throughout millions of years of independent evolution.
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Affiliation(s)
- N J Besansky
- Department of Biological Sciences, University of Notre Dame, IN 46556, USA.
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65
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Sarkar A, Coates CJ, Whyard S, Willhoeft U, Atkinson PW, O'Brochta DA. The Hermes element from Musca domestica can transpose in four families of cyclorrhaphan flies. Genetica 1997; 99:15-29. [PMID: 9226434 DOI: 10.1007/bf02259495] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Transgenic insect technology will provide opportunities to explore the basic biology of a broad range of insect species in ways that will prove insightful and important. It is also a technology that will provide opportunities to manipulate the genotypes of insects of practical significance to the health and welfare of humans. The Hermes transposable element from the housefly, Musca domestica, is a short inverted repeat-type element related to hobo from Drosophila melanogaster, Ac from Zea mays, and Tam3 from Antirrhinum majus. It has potential to become a versatile and efficient broad host-range insect transformation vector. The ability of Hermes to transpose when introduced into five species of diptera from four divergent families was tested using an in vivo, interplasmid transpositional recombination assay. Hermes was capable of transposing in all species tested, demonstrating that Hermes has a broad host-range. In addition, the rates of transposition were sufficiently high in all species tested to suggest that Hermes will be an efficient gene transfer vector in a wide range of insect species. The Hermes element also revealed a pattern of integration into the target substrate that permitted factors determining integration site selection to be identified. Primary nucleotide sequence of the integration site played a role as did proximity to preferred integration sites and the nucleosomal organization of the target.
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Affiliation(s)
- A Sarkar
- Center for Agricultural Biotechnology, University of Maryland Biotechnology Institute, College Park 20742-4450, USA
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