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Isaacs AT, Mawejje HD, Tomlinson S, Rigden DJ, Donnelly MJ. Genome-wide transcriptional analyses in Anopheles mosquitoes reveal an unexpected association between salivary gland gene expression and insecticide resistance. BMC Genomics 2018; 19:225. [PMID: 29587635 PMCID: PMC5870100 DOI: 10.1186/s12864-018-4605-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 03/14/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND To combat malaria transmission, the Ugandan government has embarked upon an ambitious programme of indoor residual spraying (IRS) with a carbamate class insecticide, bendiocarb. In preparation for this campaign, we characterized bendiocarb resistance and associated transcriptional variation among Anopheles gambiae s.s. mosquitoes from two sites in Uganda. RESULTS Gene expression in two mosquito populations displaying some resistance to bendiocarb (95% and 79% An. gambiae s.l. WHO tube bioassay mortality in Nagongera and Kihihi, respectively) was investigated using whole-genome microarrays. Significant overexpression of several genes encoding salivary gland proteins, including D7r2 and D7r4, was detected in mosquitoes from Nagongera. In Kihihi, D7r4, two detoxification-associated genes (Cyp6m2 and Gstd3) and an epithelial serine protease were among the genes most highly overexpressed in resistant mosquitoes. Following the first round of IRS in Nagongera, bendiocarb-resistant mosquitoes were collected, and real-time quantitative PCR analyses detected significant overexpression of D7r2 and D7r4 in resistant mosquitoes. A single nucleotide polymorphism located in a non-coding transcript downstream of the D7 genes was found at a significantly higher frequency in resistant individuals. In silico modelling of the interaction between D7r4 and bendiocarb demonstrated similarity between the insecticide and serotonin, a known ligand of D7 proteins. A meta-analysis of published microarray studies revealed a recurring association between D7 expression and insecticide resistance across Anopheles species and locations. CONCLUSIONS A whole-genome microarray approach identified an association between novel insecticide resistance candidates and bendiocarb resistance in Uganda. In addition, a single nucleotide polymorphism associated with this resistance mechanism was discovered. The use of such impartial screening methods allows for discovery of resistance candidates that have no previously-ascribed function in insecticide binding or detoxification. Characterizing these novel candidates will broaden our understanding of resistance mechanisms and yield new strategies for combatting widespread insecticide resistance among malaria vectors.
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Affiliation(s)
- Alison T Isaacs
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | | | - Sean Tomlinson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Daniel J Rigden
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Martin J Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK.,Malaria Programme, Wellcome Trust Sanger Institute, Cambridge, UK
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Isaacs AT, Lynd A, Donnelly MJ. Insecticide-induced leg loss does not eliminate biting and reproduction in Anopheles gambiae mosquitoes. Sci Rep 2017; 7:46674. [PMID: 28440300 PMCID: PMC5404223 DOI: 10.1038/srep46674] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 03/24/2017] [Indexed: 11/09/2022] Open
Abstract
Recent successes in malaria control have been largely attributable to the deployment of insecticide-based vector control tools such as bed nets and indoor residual spraying. Pyrethroid-treated bed nets are acutely neurotoxic to mosquitoes, inducing symptoms such as loss of coordination, paralysis, and violent spasms. One result of pyrethroid exposure often seen in laboratory tests is mosquito leg loss, a condition that has thus far been assumed to equate to mortality, as females are not expected to blood feed. However, whilst limb loss is unlikely to be adaptive, females with missing limbs may play a role in the propagation of both their species and pathogens. To test the hypothesis that leg loss inhibits mosquitoes from biting and reproducing, mosquitoes with one, two, or six legs were evaluated for their success in feeding upon a human. These experiments demonstrated that insecticide-induced leg loss had no significant effect upon blood feeding or egg laying success. We conclude that studies of pyrethroid efficacy should not discount mosquitoes that survive insecticide exposure with fewer than six legs, as they may still be capable of biting humans, reproducing, and contributing to malaria transmission.
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Affiliation(s)
- Alison T Isaacs
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Amy Lynd
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Martin J Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK.,Malaria Programme, Wellcome Trust Sanger Institute, Cambridge, UK
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3
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Donnelly MJ, Isaacs AT, Weetman D. Identification, Validation, and Application of Molecular Diagnostics for Insecticide Resistance in Malaria Vectors. Trends Parasitol 2015; 32:197-206. [PMID: 26750864 DOI: 10.1016/j.pt.2015.12.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/27/2015] [Accepted: 12/02/2015] [Indexed: 12/20/2022]
Abstract
Insecticide resistance is a major obstacle to control of Anopheles malaria mosquitoes in sub-Saharan Africa and requires an improved understanding of the underlying mechanisms. Efforts to discover resistance genes and DNA markers have been dominated by candidate gene and quantitative trait locus studies of laboratory strains, but with greater availability of genome sequences a shift toward field-based agnostic discovery is anticipated. Mechanisms evolve continually to produce elevated resistance yielding multiplicative diagnostic markers, co-screening of which can give high predictive value. With a shift toward prospective analyses, identification and screening of resistance marker panels will boost monitoring and programmatic decision making.
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Affiliation(s)
- Martin J Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; Malaria Programme, Wellcome Trust Sanger Institute, Cambridge, UK.
| | - Alison T Isaacs
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
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Redmond SN, Eiglmeier K, Mitri C, Markianos K, Guelbeogo WM, Gneme A, Isaacs AT, Coulibaly B, Brito-Fravallo E, Maslen G, Mead D, Niare O, Traore SF, Sagnon N, Kwiatkowski D, Riehle MM, Vernick KD. Association mapping by pooled sequencing identifies TOLL 11 as a protective factor against Plasmodium falciparum in Anopheles gambiae. BMC Genomics 2015; 16:779. [PMID: 26462916 PMCID: PMC4603968 DOI: 10.1186/s12864-015-2009-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 10/03/2015] [Indexed: 11/16/2022] Open
Abstract
Background The genome-wide association study (GWAS) techniques that have been used for genetic mapping in other organisms have not been successfully applied to mosquitoes, which have genetic characteristics of high nucleotide diversity, low linkage disequilibrium, and complex population stratification that render population-based GWAS essentially unfeasible at realistic sample size and marker density. Methods We designed a novel mapping strategy for the mosquito system that combines the power of linkage mapping with the resolution afforded by genetic association. We established founder colonies from West Africa, controlled for diversity, linkage disequilibrium and population stratification. Colonies were challenged by feeding on the infectious stage of the human malaria parasite, Plasmodium falciparum, mosquitoes were phenotyped for parasite load, and DNA pools for phenotypically similar mosquitoes were Illumina sequenced. Phenotype-genotype mapping was carried out in two stages, coarse and fine. Results In the first mapping stage, pooled sequences were analysed genome-wide for intervals displaying relativereduction in diversity between phenotype pools, and candidate genomic loci were identified for influence upon parasite infection levels. In the second mapping stage, focused genotyping of SNPs from the first mapping stage was carried out in unpooled individual mosquitoes and replicates. The second stage confirmed significant SNPs in a locus encoding two Toll-family proteins. RNAi-mediated gene silencing and infection challenge revealed that TOLL 11 protects mosquitoes against P. falciparum infection. Conclusions We present an efficient and cost-effective method for genetic mapping using natural variation segregating in defined recent Anopheles founder colonies, and demonstrate its applicability for mapping in a complex non-model genome. This approach is a practical and preferred alternative to population-based GWAS for first-pass mapping of phenotypes in Anopheles. This design should facilitate mapping of other traits involved in physiology, epidemiology, and behaviour. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2009-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Seth N Redmond
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France.
| | - Karin Eiglmeier
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France.
| | - Christian Mitri
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France.
| | - Kyriacos Markianos
- Program in Genomics, Boston Children's Hospital, Harvard Medical School, 3 Blackfan Street, Boston, MA, 02115, USA.
| | - Wamdaogo M Guelbeogo
- Centre National de Recherche et de Formation sur le Paludisme, 1487 Avenue de l'Oubritenga, 01 BP 2208, Ouagadougou, Burkina Faso.
| | - Awa Gneme
- Centre National de Recherche et de Formation sur le Paludisme, 1487 Avenue de l'Oubritenga, 01 BP 2208, Ouagadougou, Burkina Faso.
| | - Alison T Isaacs
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France.
| | - Boubacar Coulibaly
- Malaria Research and Training Centre, Faculty of Medicine and Dentistry, University of Mali, Point G, Bamako, Mali.
| | - Emma Brito-Fravallo
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France.
| | - Gareth Maslen
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK. .,Wellcome Trust Centre for Human Genetics, Oxford, UK.
| | - Daniel Mead
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK. .,Wellcome Trust Centre for Human Genetics, Oxford, UK.
| | - Oumou Niare
- Malaria Research and Training Centre, Faculty of Medicine and Dentistry, University of Mali, Point G, Bamako, Mali.
| | - Sekou F Traore
- Malaria Research and Training Centre, Faculty of Medicine and Dentistry, University of Mali, Point G, Bamako, Mali.
| | - N'Fale Sagnon
- Centre National de Recherche et de Formation sur le Paludisme, 1487 Avenue de l'Oubritenga, 01 BP 2208, Ouagadougou, Burkina Faso.
| | - Dominic Kwiatkowski
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK. .,Wellcome Trust Centre for Human Genetics, Oxford, UK.
| | - Michelle M Riehle
- Department of Microbiology, University of Minnesota, 1500 Gortner Avenue, Saint Paul, MN 55108, USA.
| | - Kenneth D Vernick
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France. .,Malaria Research and Training Centre, Faculty of Medicine and Dentistry, University of Mali, Point G, Bamako, Mali.
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Isaacs AT, Jasinskiene N, Tretiakov M, Thiery I, Zettor A, Bourgouin C, James AA. Transgenic Anopheles stephensi coexpressing single-chain antibodies resist Plasmodium falciparum development. Proc Natl Acad Sci U S A 2012; 109:E1922-30. [PMID: 22689959 PMCID: PMC3396534 DOI: 10.1073/pnas.1207738109] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Anopheles stephensi mosquitoes expressing m1C3, m4B7, or m2A10 single-chain antibodies (scFvs) have significantly lower levels of infection compared to controls when challenged with Plasmodium falciparum, a human malaria pathogen. These scFvs are derived from antibodies specific to a parasite chitinase, the 25 kDa protein and the circumsporozoite protein, respectively. Transgenes comprising m2A10 in combination with either m1C3 or m4B7 were inserted into previously-characterized mosquito chromosomal "docking" sites using site-specific recombination. Transgene expression was evaluated at four different genomic locations and a docking site that permitted tissue- and sex-specific expression was researched further. Fitness studies of docking site and dual scFv transgene strains detected only one significant fitness cost: adult docking-site males displayed a late-onset reduction in survival. The m4B7/m2A10 mosquitoes challenged with P. falciparum had few or no sporozoites, the parasite stage infective to humans, in three of four experiments. No sporozoites were detected in m1C3/m2A10 mosquitoes in challenge experiments when both genes were induced at developmentally relevant times. These studies support the conclusion that expression of a single copy of a dual scFv transgene can completely inhibit parasite development without imposing a fitness cost on the mosquito.
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Affiliation(s)
- Alison T. Isaacs
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA 92697-4500
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900
| | - Nijole Jasinskiene
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900
| | - Mikhail Tretiakov
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900
| | - Isabelle Thiery
- Institut Pasteur, Center for Production and Infection of Anopheles, 75724 Paris, cedex 15, France; and
| | - Agnès Zettor
- Institut Pasteur, Center for Production and Infection of Anopheles, 75724 Paris, cedex 15, France; and
| | - Catherine Bourgouin
- Institut Pasteur, Center for Production and Infection of Anopheles, 75724 Paris, cedex 15, France; and
- Institut Pasteur, Unité Génétique et Génomique des Insectes Vecteurs-Centre National de la Recherche Scientifique URA 3012, 75724 Paris, cedex 15, France
| | - Anthony A. James
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA 92697-4500
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900
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6
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Franz AWE, Jasinskiene N, Sanchez-Vargas I, Isaacs AT, Smith MR, Khoo CCH, Heersink MS, James AA, Olson KE. Comparison of transgene expression in Aedes aegypti generated by mariner Mos1 transposition and ΦC31 site-directed recombination. Insect Mol Biol 2011; 20:587-98. [PMID: 21699593 PMCID: PMC3556457 DOI: 10.1111/j.1365-2583.2011.01089.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Transgenic mosquitoes generated by transposable elements (TEs) often poorly express transgenes owing to position effects. To avoid these effects, the ΦC31 site-directed recombination system was used to insert transgenes into a locus favourable for gene expression in Aedes aegypti. We describe phenotypes of mariner Mos1 TE and ΦC31 transgenic mosquitoes expressing the enhanced green fluorescent protein (EGFP) reporter in midguts of blood-fed females. Mosquitoes of nine TE-generated lines [estimated transformation frequency (TF): 9.3%] clearly expressed the eye-specific selection marker but only 2/9 lines robustly expressed the EGFP reporter. The piggyBac TE-generated ΦC31 docking strain, attP26, supported recombination with attB site containing donors at an estimated TF of 1.7-4.9%. Using a codon-optimized ΦC31 integrase mutant instead of the 'wild-type' enzyme did not affect TF. Site-directed recombination of line attP26 with an attB-containing donor expressing EGFP from the Ae. aegypti carboxypeptidase promoter produced one transgenic line with blood-fed females expressing the reporter in midgut tissue. Docking strain attP26 also supported robust expression of Flock House virus B2 from the Ae. aegypti polyubiquitin promoter. Our data confirm that eye-specific selection marker expression alone is not a reliable indicator for robust gene-of-interest expression in Ae. aegypti and that the ΦC31 system can ensure predictable transgene expression in this mosquito species.
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Affiliation(s)
- Alexander W E Franz
- Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA.
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Isaacs AT, Li F, Jasinskiene N, Chen X, Nirmala X, Marinotti O, Vinetz JM, James AA. Engineered resistance to Plasmodium falciparum development in transgenic Anopheles stephensi. PLoS Pathog 2011; 7:e1002017. [PMID: 21533066 PMCID: PMC3080844 DOI: 10.1371/journal.ppat.1002017] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 02/10/2011] [Indexed: 01/16/2023] Open
Abstract
Transposon-mediated transformation was used to produce Anopheles
stephensi that express single-chain antibodies (scFvs) designed to
target the human malaria parasite, Plasmodium falciparum. The
scFvs, m1C3, m4B7, and m2A10, are derived from mouse monoclonal antibodies that
inhibit either ookinete invasion of the midgut or sporozoite invasion of
salivary glands. The scFvs that target the parasite surface, m4B7 and m2A10,
were fused to an Anopheles gambiae antimicrobial peptide,
Cecropin A. Previously-characterized Anopheles cis-acting DNA
regulatory elements were included in the transgenes to coordinate scFv
production with parasite development. Gene amplification and immunoblot analyses
showed promoter-specific increases in transgene expression in blood-fed females.
Transgenic mosquito lines expressing each of the scFv genes had significantly
lower infection levels than controls when challenged with P.
falciparum. Malaria eradication will require vector-control strategies that are both
self-sustaining and not affected by migration of infected humans and mosquitoes.
Replacement of wild malaria-susceptible mosquito populations with transgenic
strains refractory to parasite development could interrupt the cycle of disease
transmission and support eradication efforts. Production of P.
falciparum-resistant mosquitoes is a necessary first step towards
investigating the population replacement strategy. Here we show that An.
stephensi engineered to produce P.
falciparum-targeting effector molecules are resistant to this important
human malaria parasite. Two of the three effector molecules represent a novel
combination of components derived from the immune systems of mosquitoes and
mice. An important feature of these molecules is that they are unlikely to
significantly harm the mosquito, as the mosquito component is an
Anopheles antimicrobial peptide with activity against
Plasmodium, while the other component is based on a murine
antibody selected for its ability to bind specifically to a parasite protein.
Transgenes with this design coupled with a gene-drive system could be used
alongside vaccines and drugs to provide sustainable local elimination of malaria
as part of a long-term strategy for eradication.
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Affiliation(s)
- Alison T. Isaacs
- Department of Microbiology and Molecular Genetics, School of Medicine,
University of California, Irvine, California, United States of
America
| | - Fengwu Li
- Division of Infectious Diseases, Department of Medicine, University of
California-San Diego School of Medicine, La Jolla, California, United States of
America
| | - Nijole Jasinskiene
- Department of Molecular Biology and Biochemistry, University of
California, Irvine, California, United States of America
| | - Xiaoguang Chen
- Department of Parasitology, School of Public Health and Tropical
Medicine, Southern Medical University, Guang Zhou, GD, China
| | - Xavier Nirmala
- Department of Entomology and Nematology, University of Florida,
Gainesville, Florida, United States of America
- USDA/ARS, Center for Medical, Agricultural and Veterinary Entomology,
Gainesville, Florida, United States of America
| | - Osvaldo Marinotti
- Department of Molecular Biology and Biochemistry, University of
California, Irvine, California, United States of America
| | - Joseph M. Vinetz
- Division of Infectious Diseases, Department of Medicine, University of
California-San Diego School of Medicine, La Jolla, California, United States of
America
| | - Anthony A. James
- Department of Microbiology and Molecular Genetics, School of Medicine,
University of California, Irvine, California, United States of
America
- Department of Molecular Biology and Biochemistry, University of
California, Irvine, California, United States of America
- * E-mail:
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Amenya DA, Bonizzoni M, Isaacs AT, Jasinskiene N, Chen H, Marinotti O, Yan G, James AA. Comparative fitness assessment of Anopheles stephensi transgenic lines receptive to site-specific integration. Insect Mol Biol 2010; 19:263-9. [PMID: 20113372 PMCID: PMC2862888 DOI: 10.1111/j.1365-2583.2009.00986.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Genetically modified mosquitoes that are unable to transmit pathogens offer opportunities for controlling vector-borne diseases such as malaria and dengue. Site-specific gene recombination technologies are advantageous in the development of these insects because antipathogen effector genes can be inserted at integration sites in the genome that cause the least alteration in mosquito fitness. Here we describe Anopheles stephensi transgenic lines containing phi C31 attP'docking' sites linked to a fluorescent marker gene. Chromosomal insertion sites were determined and life-table parameters were assessed for transgenic mosquitoes of each line. No significant differences in fitness between the transgenic and nontransgenic mosquitoes were detected in this study. These transgenic lines are suitable for future site-specific integrations of antiparasite transgenes into the attP sites.
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Affiliation(s)
- Dolphine A. Amenya
- Program in Public Health, University of California, Irvine, CA 92697
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697
| | - Mariangela Bonizzoni
- Program in Public Health, University of California, Irvine, CA 92697
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697
| | - Alison T. Isaacs
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697
| | - Nijole Jasinskiene
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697
| | - Hong Chen
- Program in Public Health, University of California, Irvine, CA 92697
| | - Osvaldo Marinotti
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, CA 92697
| | - Anthony A. James
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697
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Wiley CD, Matundan HH, Duselis AR, Isaacs AT, Vrana PB. Patterns of hybrid loss of imprinting reveal tissue- and cluster-specific regulation. PLoS One 2008; 3:e3572. [PMID: 18958286 PMCID: PMC2570336 DOI: 10.1371/journal.pone.0003572] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 10/10/2008] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Crosses between natural populations of two species of deer mice, Peromyscus maniculatus (BW), and P. polionotus (PO), produce parent-of-origin effects on growth and development. BW females mated to PO males (bwxpo) produce growth-retarded but otherwise healthy offspring. In contrast, PO females mated to BW males (POxBW) produce overgrown and severely defective offspring. The hybrid phenotypes are pronounced in the placenta and include POxBW conceptuses which lack embryonic structures. Evidence to date links variation in control of genomic imprinting with the hybrid defects, particularly in the POxBW offspring. Establishment of genomic imprinting is typically mediated by gametic DNA methylation at sites known as gDMRs. However, imprinted gene clusters vary in their regulation by gDMR sequences. METHODOLOGY/PRINCIPAL FINDINGS Here we further assess imprinted gene expression and DNA methylation at different cluster types in order to discern patterns. These data reveal POxBW misexpression at the Kcnq1ot1 and Peg3 clusters, both of which lose ICR methylation in placental tissues. In contrast, some embryonic transcripts (Peg10, Kcnq1ot1) reactivated the silenced allele with little or no loss of DNA methylation. Hybrid brains also display different patterns of imprinting perturbations. Several cluster pairs thought to use analogous regulatory mechanisms are differentially affected in the hybrids. CONCLUSIONS/SIGNIFICANCE These data reinforce the hypothesis that placental and somatic gene regulation differs significantly, as does that between imprinted gene clusters and between species. That such epigenetic regulatory variation exists in recently diverged species suggests a role in reproductive isolation, and that this variation is likely to be adaptive.
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Affiliation(s)
- Christopher D. Wiley
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Harry H. Matundan
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Amanda R. Duselis
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Alison T. Isaacs
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Paul B. Vrana
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, California, United States of America
- * E-mail:
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