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Kamau L, Bennett KL, Ochomo E, Herren J, Agumba S, Otieno S, Omoke D, Matoke-Muhia D, Mburu D, Mwangangi J, Ramaita E, Juma EO, Mbogo C, Barasa S, Miles A. The Anopheles coluzzii range extends into Kenya: Detection, insecticide resistance profiles and population genetic structure in relation to conspecific populations in West and Central Africa. RESEARCH SQUARE 2024:rs.3.rs-3953608. [PMID: 38410447 PMCID: PMC10896386 DOI: 10.21203/rs.3.rs-3953608/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Background Anopheles coluzzii is a primary vector of malaria found in West and Central Africa, but its presence has hitherto never been documented in Kenya. A thorough understanding of vector bionomics is important as it enables the implementation of targeted and effective vector control interventions. Malaria vector surveillance efforts in the country have tended to focus on historically known primary vectors. In the current study, we sought to determine the taxonomic status of samples collected from five different malaria epidemiological zones in Kenya as well asdescribe the population genetic structure and insecticide resistance profiles in relation to other An. coluzzi populations. Methods Mosquitoes were sampled as larvae from Busia, Kwale, Turkana, Kirinyaga and Kiambu counties, representing the range of malaria endemicities in Kenya, in 2019 and 2021 and emergent adults analysed using Whole Genome Sequencing data processed in accordance with the Anopheles gambiae 1000 Genomes Project phase 3. Where available, historical samples from the same sites were included for WGS. Results This study reports the detection of Anopheles coluzzii for the first time in Kenya. The species was detected in Turkana County across all three time points sampled and its presence confirmed through taxonomic analysis. Additionally, we found a lack of strong population genetic differentiation between An. coluzzii from Kenya and those from the more northerly regions of West and Central Africa, suggesting they represent a connected extension to the known species range. Mutations associated with target-site resistance to DDT and pyrethroids and metabolic resistance to DDT were found at high frequencies of ~60%. The profile and frequencies of the variants observed were similar to An. coluzzii from West and Central Africa but the ace-1 mutation linked to organophosphate and carbamate resistance present in An. coluzzii from coastal West Africa was absent in Kenya. Conclusions These findings emphasise the need for the incorporation of genomics in comprehensive and routine vector surveillance to inform on the range of malaria vector species, and their insecticide resistance status to inform the choice of effective vector control approaches.
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Affiliation(s)
- Luna Kamau
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute
| | - Kelly L Bennett
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute
| | - Eric Ochomo
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute
| | - Jeremy Herren
- International Centre of Insect Physiology and Ecology
| | - Silas Agumba
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute
| | - Samson Otieno
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute
| | - Diana Omoke
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute
| | | | - Joseph Mwangangi
- Centre for Geographic Medicine Research-Coast (CGMR-C), Kenya Medical Research Institute
| | - Edith Ramaita
- Ministry of Health - National Malaria Control Programme (NMCP)
| | | | | | - Sonia Barasa
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute
| | - Alistair Miles
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute
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2
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Tondossama N, Coulibaly ZI, Traoré I, Ako BA, Zoh DD, Virgillito C, Guindo-Coulibaly N, Serini P, Assouho FK, Dia I, Touré AO, Adja MA, Caputo B, della Torre A, Pichler V. High Levels of Admixture in Anopheles gambiae Populations from Côte d'Ivoire Revealed by Multilocus Genotyping. INSECTS 2022; 13:1090. [PMID: 36555000 PMCID: PMC9782310 DOI: 10.3390/insects13121090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/22/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
Anopheles coluzzii and An. gambiae-the two most recently radiated species of the An. gambiae complex and the major Afrotropical malaria vector species-are identified by markers in the X-centromeric IGS rDNA region. Putative IGS-hybrids are rarely found in the field, except in restricted areas where genomic studies have led to the hypothesis that the observed IGS-patterns are due to cryptic taxa rather than to hybridization between the two species. We investigated the genome-wide levels of admixture in two villages in Côte d'Ivoire where high levels of IGS-hybrids have been detected, confirming unparalleled high frequencies in the coastal village. Genotyping of 24 Ancestry Informative Markers (AIMs) along the three chromosomes produced discordant results between the IGS-marker and the multilocus genotype obtained for AIMs across the whole genome (29%) as well as AIMs on chromosome-X (considered to be fundamental for species reproductive isolation) only (21%). Results highlight a complicated pattern of admixture that deserves deeper genomic analyses to understand better possible underlying causes (from extensive processes of hybridization to the existence of different cryptic taxa), and stress the need of developing advanced diagnostics for An. coluzzii, An. gambiae and putative new taxa, instrumental for assessing taxon-specific epidemiological characters.
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Affiliation(s)
- Naminata Tondossama
- Laboratoire de Biologie et Santé, UFR Biosciences, Université Félix Houphouet Boigny Cocody, Abidjan 01 BP V34, Côte d’Ivoire
- Entomology and Herpetology Unit, Institut Pasteur de Côte d’Ivoire, Abidjan 01 PB 490, Côte d’Ivoire
| | - Zanakoungo I. Coulibaly
- Entomology and Herpetology Unit, Institut Pasteur de Côte d’Ivoire, Abidjan 01 PB 490, Côte d’Ivoire
| | - Issouf Traoré
- Laboratoire de Biologie et Santé, UFR Biosciences, Université Félix Houphouet Boigny Cocody, Abidjan 01 BP V34, Côte d’Ivoire
- Entomology and Herpetology Unit, Institut Pasteur de Côte d’Ivoire, Abidjan 01 PB 490, Côte d’Ivoire
| | - Bérenger A. Ako
- Malaria Unit, Institut Pasteur de Côte d’Ivoire, Abidjan 01 PB 490, Côte d’Ivoire
| | - Danielle D. Zoh
- Laboratoire de Biologie et Santé, UFR Biosciences, Université Félix Houphouet Boigny Cocody, Abidjan 01 BP V34, Côte d’Ivoire
- Institut Pierre Richet/Institut National de Santé Publique, Bouaké 01 BP 1500, Côte d’Ivoire
| | - Chiara Virgillito
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma “La Sapienza,” Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Négnorogo Guindo-Coulibaly
- Laboratoire de Biologie et Santé, UFR Biosciences, Université Félix Houphouet Boigny Cocody, Abidjan 01 BP V34, Côte d’Ivoire
| | - Paola Serini
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma “La Sapienza,” Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Fabrice K. Assouho
- Institut Pierre Richet/Institut National de Santé Publique, Bouaké 01 BP 1500, Côte d’Ivoire
| | - Ibrahima Dia
- Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, Dakar BP 220, Senegal
| | - Andre O. Touré
- Malaria Unit, Institut Pasteur de Côte d’Ivoire, Abidjan 01 PB 490, Côte d’Ivoire
| | - Maurice A. Adja
- Laboratoire de Biologie et Santé, UFR Biosciences, Université Félix Houphouet Boigny Cocody, Abidjan 01 BP V34, Côte d’Ivoire
- Institut Pierre Richet/Institut National de Santé Publique, Bouaké 01 BP 1500, Côte d’Ivoire
| | - Beniamino Caputo
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma “La Sapienza,” Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Alessandra della Torre
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma “La Sapienza,” Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Verena Pichler
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma “La Sapienza,” Piazzale Aldo Moro, 5, 00185 Rome, Italy
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Wragge SE, Venter N, Touré D, Hunt RH, Coetzee M. New distribution record of Anopheles rivulorum-like from Sadiola, Mali, with notes on malaria vector insecticide resistance. Trans R Soc Trop Med Hyg 2021; 115:495-499. [PMID: 33096555 DOI: 10.1093/trstmh/traa113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/06/2020] [Accepted: 10/06/2020] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The SEMOS gold mine in Sadiola, southwestern Mali, has been implementing a malaria vector control programme for 15 y using indoor residual house spraying and sporadic larval control. Periodic screening of the vector populations have been carried out over the years to provide information to the control programme, mainly on vector species present and their insecticide resistance status. The data from five entomological surveys, carried out in 2006, 2011, 2014, 2016 and 2018, are presented. METHODS Adult mosquitoes were collected resting on walls inside houses and on verandas. Insecticide susceptibility assays were carried out and mosquitoes subsequently identified by species using molecular assays. RESULTS The major malaria vector mosquitoes, Anopheles gambiae and Anopheles arabiensis were abundant at each sampling period with Anopheles coluzzii and Anopheles funestus being rare or absent. Anopheles rivulorum was identified in 2006 and Anopheles leesoni in 2016. The presence of Anopheles rivulorum-like, identified for the first time in 2018, was not screened for in previous surveys. Insecticide susceptibility bioassays showed resistance in both A. gambiae and A. arabiensis to pyrethroids, carbamates and dichlorodiphenyltrichloroethane over the 12 y. CONCLUSIONS This is the first record of A. rivulorum-like west of Côte d'Ivoire. Resistance levels to the three classes of insecticides were variable but appeared to decrease after pyrethroids were discontinued for house spraying.
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Affiliation(s)
- Sue-Ellen Wragge
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,SEMOS Gold Mine, Sadiola, Kayes District, Mali
| | - Nelius Venter
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for Emerging Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
| | | | - Richard H Hunt
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for Emerging Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Maureen Coetzee
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for Emerging Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
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4
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Chabi J, Van’t Hof A, N’dri LK, Datsomor A, Okyere D, Njoroge H, Pipini D, Hadi MP, de Souza DK, Suzuki T, Dadzie SK, Jamet HP. Rapid high throughput SYBR green assay for identifying the malaria vectors Anopheles arabiensis, Anopheles coluzzii and Anopheles gambiae s.s. Giles. PLoS One 2019; 14:e0215669. [PMID: 31002694 PMCID: PMC6474623 DOI: 10.1371/journal.pone.0215669] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 04/05/2019] [Indexed: 12/04/2022] Open
Abstract
The Anopheles gambiae sensu lato species complex consists of a number of cryptic species with different habitats and behaviours. These morphologically indistinct species are identified by chromosome banding. Several molecular diagnostic techniques for distinguishing between An. coluzzii and An. gambiae are still under improvement. Although, the current SINE method for identification between An. coluzzii and An. gambiae works reliably, this study describes a refinement of the SINE method to increase sensitivity for identification of An. coluzzii, An. gambiae and An. arabiensis based on amplicon dissociation curve characteristics. Field-collected samples, laboratory-reared colonies and crossed specimens of the two species were used for the design of the protocol. An. gambiae, An. coluzzii, and hybrids of the two species were sampled from Ghana and An. arabiensis from Kenya. Samples were first characterised using conventional SINE PCR method, and further assayed using SYBR green, an intercalating fluorescent dye. The three species and hybrids were clearly differentiated using the melting temperature of the dissociation curves, with derivative peaks at 72°C for An. arabiensis, 75°C for An. gambiae and 86°C for An. coluzzii. The hybrids (An. gambiae / An. coluzzii) showed both peaks. This work is the first to describe a SYBR green real time PCR method for the characterization of An. arabiensis, An. gambiae and An. coluzzii and was purposely designed for basic melt-curve analysis (rather than high-resolution melt-curve) to allow it to be used on a wide range of real-time PCR machines.
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Affiliation(s)
- Joseph Chabi
- Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Arjen Van’t Hof
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Louis K. N’dri
- Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Alex Datsomor
- Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Dora Okyere
- Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Harun Njoroge
- Kemri-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Dimitra Pipini
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Melinda P. Hadi
- Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
- Vestergaard Frandsen East Africa, Nairobi, Kenya
| | - Dziedzom K. de Souza
- Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Takashi Suzuki
- Section Environmental Parasitology, Kobe-Tokiwa University, Nagata-Ku, Japan
| | - Samuel K. Dadzie
- Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Helen P. Jamet
- Vestergaard regional office, Washington DC, United States of America
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5
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Boussougou-Sambe ST, Eyisap WE, Tasse GCT, Mandeng SE, Mbakop LR, Enyong P, Etang J, Fokam EB, Awono-Ambene PH. Insecticide susceptibility status of Anopheles gambiae (s.l.) in South-West Cameroon four years after long-lasting insecticidal net mass distribution. Parasit Vectors 2018; 11:391. [PMID: 29973260 PMCID: PMC6033221 DOI: 10.1186/s13071-018-2979-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 06/25/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Members of the Anopheles gambiae (s.l.) complex are one of the major vectors of malaria in Africa. LLINs and IRS are the most effective tools used in vector control of malaria. However, their effectiveness may be hampered by the development and spread of insecticide resistance in the target vectors species. The objective of this study was to assess the susceptibility of Anopheles gambiae (s.l.) mosquitoes from South-West Cameroon to deltamethrin, permethrin and to malathion, four years after the mass deployment of LLINs. METHODS Anopheles larvae were collected from Limbe, Tiko and Buea, three cities of the Fako division and reared until adult emergence. Adult mosquitoes from field larvae were identified as belonging to the Anopheles gambiae (s.l.) complex using standard identification keys. Susceptibility of mosquito samples to deltamethrin, permethrin and malathion was assessed using WHO susceptibility tests protocol for adult mosquitoes. Molecular identification of tested samples was performed using the PCR SINE200 protocol and by PCR-RFLP. The kdr alleles were genotyped using the hot ligation oligonucleotide assay (HOLA). RESULTS Two species of the An. gambiae (s.l.) complex, An. coluzzii and An. gambiae (s.s.) were identified in all three study locations with high proportions of An. coluzzii in Limbe (84.06%) and Tiko (92.2%), while in Buea, An. coluzzii (55.6%) and An. gambiae (s.s.) (44.4%) occurred almost in the same proportions. Tested samples were found resistant to pyrethroids (deltamethrin and permethrin) in all locations (< 90% mortality), with > 3-fold increase of KDT50 values compared with the Kisumu susceptible reference strain of An. gambiae (s.s.). However, the mosquito populations from Limbe and Buea were fully susceptible to malathion. The L1014F kdr was found in both An. coluzzii and An. gambiae (s.s.) with the highest frequencies found in An. gambiae (s.l.) populations from Tiko (94%) and Buea (90%) compared with the Limbe population (66%) (P = 0.00063, df = 2). No kdr L1014S was observed in analyzed samples. CONCLUSIONS These findings reemphasize the ongoing development of An. gambiae (s.l.) resistance to pyrethroids used in impregnating LLINs and suggest the use of malathion as an alternative insecticide for IRS in complementarity with LLINs.
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Affiliation(s)
- Stravensky Térence Boussougou-Sambe
- Microbiology and Parasitology Department, University of Buea, P.O. Box 63, Buea, Cameroon.,Institut de Recherche de Yaoundé, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroon.,Centre de Recherches Médicales de Lambaréné (CERMEL), P.O Box 242, Lambaréné, Gabon.,Institute of Tropical Medicine, University of Tübingen, Wilhemstrasse 27, P.O. Box 72074, Tübingen, Germany
| | - Wolfgang Ekoko Eyisap
- Institut de Recherche de Yaoundé, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroon.,Laboratory of Animal Biology and Physiology, University of Douala, PO Box 24157, Douala, Cameroon
| | - Geraud Canis Taboue Tasse
- Laboratory for Biodiversity and Conservation Biology, University of Buea, P.O. Box 63, Buea, Cameroon.,Department of Zoology and Animal Physiology, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Stanislas Elysee Mandeng
- Institut de Recherche de Yaoundé, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroon.,Department of Biology and Animal Physiology, University of Yaoundé I, P.O. Box 3851, Messa, Yaoundé, Cameroon
| | - Lili Ranaise Mbakop
- Institut de Recherche de Yaoundé, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroon.,Department of Biology and Animal Physiology, University of Yaoundé I, P.O. Box 3851, Messa, Yaoundé, Cameroon
| | - Peter Enyong
- Microbiology and Parasitology Department, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Josiane Etang
- Institut de Recherche de Yaoundé, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroon.,Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 2701, Douala, Cameroon
| | - Eric Bertrand Fokam
- Laboratory for Biodiversity and Conservation Biology, University of Buea, P.O. Box 63, Buea, Cameroon.,Department of Zoology and Animal Physiology, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Parfait H Awono-Ambene
- Institut de Recherche de Yaoundé, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroon.
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Pombi M, Kengne P, Gimonneau G, Tene-Fossog B, Ayala D, Kamdem C, Santolamazza F, Guelbeogo WM, Sagnon N, Petrarca V, Fontenille D, Besansky NJ, Antonio-Nkondjio C, Dabiré RK, Della Torre A, Simard F, Costantini C. Dissecting functional components of reproductive isolation among closely related sympatric species of the Anopheles gambiae complex. Evol Appl 2017; 10:1102-1120. [PMID: 29151864 PMCID: PMC5680640 DOI: 10.1111/eva.12517] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 07/10/2017] [Indexed: 01/10/2023] Open
Abstract
Explaining how and why reproductive isolation evolves and determining which forms of reproductive isolation have the largest impact on the process of population divergence are major goals in the study of speciation. By studying recent adaptive radiations in incompletely isolated taxa, it is possible to identify barriers involved at early divergence before other confounding barriers emerge after speciation is complete. Sibling species of the Anopheles gambiae complex offer opportunities to provide insights into speciation mechanisms. Here, we studied patterns of reproductive isolation among three taxa, Anopheles coluzzii, An. gambiae s.s. and Anopheles arabiensis, to compare its strength at different spatial scales, to dissect the relative contribution of pre‐ versus postmating isolation, and to infer the involvement of ecological divergence on hybridization. Because F1 hybrids are viable, fertile and not uncommon, understanding the dynamics of hybridization in this trio of major malaria vectors has important implications for how adaptations arise and spread across the group, and in planning studies of the safety and efficacy of gene drive as a means of malaria control. We first performed a systematic review and meta‐analysis of published surveys reporting on hybrid prevalence, showing strong reproductive isolation at a continental scale despite geographically restricted exceptions. Second, we exploited our own extensive field data sets collected at a regional scale in two contrasting environmental settings, to assess: (i) levels of premating isolation; (ii) spatio/temporal and frequency‐dependent dynamics of hybridization, (iii) relationship between reproductive isolation and ecological divergence and (iv) hybrid viability penalty. Results are in accordance with ecological speciation theory predicting a positive association between the strength of reproductive isolation and degree of ecological divergence, and indicate that postmating isolation does contribute to reproductive isolation among these species. Specifically, only postmating isolation was positively associated with ecological divergence, whereas premating isolation was correlated with phylogenetic distance.
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Affiliation(s)
- Marco Pombi
- Dipartimento di Sanità Pubblica e Malattie InfettiveUniversità di Roma "Sapienza"RomeItaly.,Istituto Pasteur Italia-Fondazione Cenci-Bolognetti Rome Italy
| | - Pierre Kengne
- Institut de Recherche pour le Développement (IRD) UMR MIVEGEC (University of Montpellier, CNRS 5290 IRD 224) Centre IRD de Montpellier Montpellier France.,Organisation de Coordination pour la lutte contre les Endemies en Afrique Centrale (OCEAC) Yaoundé Cameroon
| | | | - Billy Tene-Fossog
- Institut de Recherche pour le Développement (IRD) UMR MIVEGEC (University of Montpellier, CNRS 5290 IRD 224) Centre IRD de Montpellier Montpellier France.,Organisation de Coordination pour la lutte contre les Endemies en Afrique Centrale (OCEAC) Yaoundé Cameroon
| | - Diego Ayala
- Institut de Recherche pour le Développement (IRD) UMR MIVEGEC (University of Montpellier, CNRS 5290 IRD 224) Centre IRD de Montpellier Montpellier France.,Centre International de Recherches Médicales de Franceville Franceville Gabon
| | - Colince Kamdem
- Department of Entomology University of California Riverside CA USA
| | - Federica Santolamazza
- Dipartimento di Sanità Pubblica e Malattie InfettiveUniversità di Roma "Sapienza"RomeItaly.,Istituto Pasteur Italia-Fondazione Cenci-Bolognetti Rome Italy
| | | | - N'Falé Sagnon
- Centre National de Recherche et Formation sur le Paludisme (CNRFP) Ouagadougou Burkina Faso
| | - Vincenzo Petrarca
- Dipartimento di Sanità Pubblica e Malattie InfettiveUniversità di Roma "Sapienza"RomeItaly.,Istituto Pasteur Italia-Fondazione Cenci-Bolognetti Rome Italy
| | - Didier Fontenille
- Institut de Recherche pour le Développement (IRD) UMR MIVEGEC (University of Montpellier, CNRS 5290 IRD 224) Centre IRD de Montpellier Montpellier France.,Institut Pasteur du Cambodge Phnom Penh Cambodia
| | - Nora J Besansky
- Eck Institute for Global Health & Department of Biological Sciences University of Notre Dame Notre Dame IN USA
| | | | - Roch Kounbobr Dabiré
- Institut de Recherche en Sciences de la Santé (IRSS) Bobo-Dioulasso Burkina Faso
| | - Alessandra Della Torre
- Dipartimento di Sanità Pubblica e Malattie InfettiveUniversità di Roma "Sapienza"RomeItaly.,Istituto Pasteur Italia-Fondazione Cenci-Bolognetti Rome Italy
| | - Frédéric Simard
- Institut de Recherche pour le Développement (IRD) UMR MIVEGEC (University of Montpellier, CNRS 5290 IRD 224) Centre IRD de Montpellier Montpellier France.,Organisation de Coordination pour la lutte contre les Endemies en Afrique Centrale (OCEAC) Yaoundé Cameroon.,Institut de Recherche en Sciences de la Santé (IRSS) Bobo-Dioulasso Burkina Faso
| | - Carlo Costantini
- Institut de Recherche pour le Développement (IRD) UMR MIVEGEC (University of Montpellier, CNRS 5290 IRD 224) Centre IRD de Montpellier Montpellier France.,Organisation de Coordination pour la lutte contre les Endemies en Afrique Centrale (OCEAC) Yaoundé Cameroon.,Institut de Recherche en Sciences de la Santé (IRSS) Bobo-Dioulasso Burkina Faso
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7
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Sougoufara S, Sokhna C, Diagne N, Doucouré S, Sembène PMB, Harry M. The implementation of long-lasting insecticidal bed nets has differential effects on the genetic structure of the African malaria vectors in the Anopheles gambiae complex in Dielmo, Senegal. Malar J 2017; 16:337. [PMID: 28810861 PMCID: PMC5558778 DOI: 10.1186/s12936-017-1992-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 08/10/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mosquitoes belonging to the Anopheles gambiae complex are the main vectors of malaria in sub-Saharan Africa. Among these, An. gambiae, Anopheles coluzzii and Anopheles arabiensis are the most efficient vectors and are largely distributed in sympatric locations. However, these species present ecological and behavioural differences that impact their vectorial capacity and complicate vector-control efforts, mainly based on long-lasting insecticidal bed nets (LLINs) and indoor residual spraying (IRS). In this study, the genetic structure of these three species in a Senegalese village (Dielmo) was investigated using microsatellite data in samples collected in 2006 before implementation of LLINs, in 2008, when they were introduced, and in 2010, 2 years after the use of LLINs. RESULTS In this study 611 individuals were included, namely 136 An. coluzzii, 101 An. gambiae, 6 An. coluzzii/An. gambiae hybrids and 368 An. arabiensis. According to the species, the effect of the implementation of LLINs in Dielmo is differentiated. Populations of the sister species An. coluzzii and An. gambiae regularly experienced bottleneck events, but without significant inbreeding. The Fst values suggested in 2006 a breakdown of assortative mating resulting in hybrids, but the introduction of LLINs was followed by a decrease in the number of hybrids. This suggests a decrease in mating success of hybrids, ecological maladaptation, or a lesser probability of mating between species due to a decrease in An. coluzzii population size. By contrast, the introduction of LLINs has favoured the sibling species An. arabiensis. In this study, some spatial and temporal structuration between An. arabiensis populations were detected, especially in 2008, and the higher genetic diversity observed could result from a diversifying selection. CONCLUSIONS This work demonstrates the complexity of the malaria context and shows the need to study the genetic structure of Anopheles populations to evaluate the effectiveness of vector-control tools and successful management of malaria vector control.
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Affiliation(s)
- Seynabou Sougoufara
- URMITE (Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes), UM63, CNRS 7278, IRD 198, INSERM 1095, IHU-Méditerranée Infection, Marseille, France. .,Département de Biologie Animale, Faculté des Sciences et Techniques/Université Cheikh Anta Diop, Dakar, Senegal.
| | - Cheikh Sokhna
- URMITE (Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes), UM63, CNRS 7278, IRD 198, INSERM 1095, IHU-Méditerranée Infection, Marseille, France
| | - Nafissatou Diagne
- URMITE (Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes), UM63, CNRS 7278, IRD 198, INSERM 1095, IHU-Méditerranée Infection, Marseille, France
| | - Souleymane Doucouré
- URMITE (Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes), UM63, CNRS 7278, IRD 198, INSERM 1095, IHU-Méditerranée Infection, Marseille, France
| | - Pape MBacké Sembène
- Département de Biologie Animale, Faculté des Sciences et Techniques/Université Cheikh Anta Diop, Dakar, Senegal
| | - Myriam Harry
- UMR EGCE (Évolution, Génomes, Comportement, Écologie) CNRS, IRD-Université Paris-Sud, IDEEV, Université Paris-Saclay, Gif-sur-Yvette Cedex, France
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Caputo B, Pichler V, Mancini E, Pombi M, Vicente JL, Dinis J, Steen K, Petrarca V, Rodrigues A, Pinto J, Della Torre A, Weetman D. The last bastion? X chromosome genotyping of Anopheles gambiae species pair males from a hybrid zone reveals complex recombination within the major candidate 'genomic island of speciation'. Mol Ecol 2016; 25:5719-5731. [PMID: 27661465 DOI: 10.1111/mec.13840] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 07/19/2016] [Accepted: 09/01/2016] [Indexed: 01/19/2023]
Abstract
Speciation with gene flow may be aided by reduced recombination helping to build linkage between genes involved in the early stages of reproductive isolation. Reduced recombination on chromosome X has been implicated in speciation within the Anopheles gambiae complex, species of which represent the major Afrotropical malaria vectors. The most recently diverged, morphologically indistinguishable, species pair, A. gambiae and Anopheles coluzzii, ubiquitously displays a 'genomic island of divergence' spanning over 4 Mb from chromosome X centromere, which represents a particularly promising candidate region for reproductive isolation genes, in addition to containing the diagnostic markers used to distinguish the species. Very low recombination makes the island intractable for experimental recombination studies, but an extreme hybrid zone in Guinea Bissau offers the opportunity for natural investigation of X-island recombination. SNP analysis of chromosome X hemizygous males revealed: (i) strong divergence in the X-island despite a lack of autosomal divergence; (ii) individuals with multiple-recombinant genotypes, including likely double crossovers and localized gene conversion; (iii) recombination-driven discontinuity both within and between the molecular species markers, suggesting that the utility of the diagnostics is undermined under high hybridization. The largely, but incompletely protected nature of the X centromeric genomic island is consistent with a primary candidate area for accumulation of adaptive variants driving speciation with gene flow, while permitting some selective shuffling and removal of genetic variation.
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Affiliation(s)
- Beniamino Caputo
- Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Dipartimento di Sanità Pubblica e Malattie Infettive, Università 'Sapienza', Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Verena Pichler
- Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Dipartimento di Sanità Pubblica e Malattie Infettive, Università 'Sapienza', Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Emiliano Mancini
- Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Dipartimento di Sanità Pubblica e Malattie Infettive, Università 'Sapienza', Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Marco Pombi
- Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Dipartimento di Sanità Pubblica e Malattie Infettive, Università 'Sapienza', Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - José L Vicente
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua daJunqueira, 100, 1349-008, Lisboa, Portugal
| | - Joao Dinis
- Instituto Nacional de Saúde Pública, Ministério da Saúde Pública, Avenida Combatentes da Liberdade da Pátria, Apartado 861, 1004, Bissau Codex, Guinea Bissau
| | - Keith Steen
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Pl, Liverpool, Merseyside, L3 5QA, UK
| | - Vincenzo Petrarca
- Istituto Pasteur-Fondazione Cenci-Bolognetti, Dipartimento di Biologia e Biotecnologie Charles Darwin, Università 'Sapienza', Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Amabelia Rodrigues
- Instituto Nacional de Saúde Pública, Ministério da Saúde Pública, Avenida Combatentes da Liberdade da Pátria, Apartado 861, 1004, Bissau Codex, Guinea Bissau
| | - Joao Pinto
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua daJunqueira, 100, 1349-008, Lisboa, Portugal
| | - Alessandra Della Torre
- Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Dipartimento di Sanità Pubblica e Malattie Infettive, Università 'Sapienza', Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - David Weetman
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Pl, Liverpool, Merseyside, L3 5QA, UK
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Wragge SE, Toure D, Coetzee M, Gilbert A, Christian R, Segoea G, Hunt RH, Coetzee M. Malaria control at a gold mine in Sadiola District, Mali, and impact on transmission over 10 years. Trans R Soc Trop Med Hyg 2016; 109:755-62. [PMID: 26626339 DOI: 10.1093/trstmh/trv089] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The SEMOS gold mine's malaria vector control programme forms part of the company's community responsibilities with the programme being managed by the mine's health department since 2005. METHODS Data from approximately 10 years of malaria vector control for the Sadiola District are given: namely malaria vector control methods used by the control programme, positive malaria case data and entomological surveys from 2006, 2011 and 2014. RESULTS Distribution of pyrethroid-treated bed nets and indoor residual spraying (IRS) with deltamethrin were implemented by the programme from 2005-2011. No IRS was done in 2012. Spraying with the organophosphate, pirimiphos-methyl resumed in 2013 and 2014 and was followed by a 70% drop in malaria cases in 2014. Anopheles arabiensis was the major vector present in 2006 and was susceptible to deltamethrin. In 2011 and 2014, An. gambiae s.s. was the most abundant vector with deltamethrin 24 h mortality of 68% and 19%, respectively. CONCLUSIONS Resistance to the pyrethroid deltamethrin has increased in An. gambiae s.s. since 2011, possibly due to the scale-up in distribution of long-lasting insecticide-treated bed nets. Resistance management strategies are recommended using different classes of insecticides for IRS, and including the distribution of new-generation bed nets.
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Affiliation(s)
- Sue-Ellen Wragge
- SEMOS Gold Mine, Health Department, Sadiola, Hamdallaye ACI 2000 pres' des Assurance LAFIA, B.P.E-1194, Bamako, Mali
| | - Dramane Toure
- SEMOS Gold Mine, Health Department, Sadiola, Hamdallaye ACI 2000 pres' des Assurance LAFIA, B.P.E-1194, Bamako, Mali
| | - Marelize Coetzee
- SEMOS Gold Mine, Health Department, Sadiola, Hamdallaye ACI 2000 pres' des Assurance LAFIA, B.P.E-1194, Bamako, Mali
| | - Allison Gilbert
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, 7 York Avenue, Johannesburg 2001, South Africa Centre for Opportunistic, Tropical and Hospital Infections, National Institute for Communicable Diseases, Private Bag X4, Sandringham 2131, South Africa
| | - Riann Christian
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, 7 York Avenue, Johannesburg 2001, South Africa Centre for Opportunistic, Tropical and Hospital Infections, National Institute for Communicable Diseases, Private Bag X4, Sandringham 2131, South Africa
| | - Godira Segoea
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, 7 York Avenue, Johannesburg 2001, South Africa Centre for Opportunistic, Tropical and Hospital Infections, National Institute for Communicable Diseases, Private Bag X4, Sandringham 2131, South Africa
| | - Richard H Hunt
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, 7 York Avenue, Johannesburg 2001, South Africa Centre for Opportunistic, Tropical and Hospital Infections, National Institute for Communicable Diseases, Private Bag X4, Sandringham 2131, South Africa
| | - Maureen Coetzee
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, 7 York Avenue, Johannesburg 2001, South Africa Centre for Opportunistic, Tropical and Hospital Infections, National Institute for Communicable Diseases, Private Bag X4, Sandringham 2131, South Africa
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Adaptive Potential of Hybridization among Malaria Vectors: Introgression at the Immune Locus TEP1 between Anopheles coluzzii and A. gambiae in 'Far-West' Africa. PLoS One 2015; 10:e0127804. [PMID: 26047479 PMCID: PMC4457524 DOI: 10.1371/journal.pone.0127804] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/19/2015] [Indexed: 02/02/2023] Open
Abstract
“Far-West” Africa is known to be a secondary contact zone between the two major malaria vectors Anopheles coluzzii and A. gambiae. We investigated gene-flow and potentially adaptive introgression between these species along a west-to-east transect in Guinea Bissau, the putative core of this hybrid zone. To evaluate the extent and direction of gene flow, we genotyped site 702 in Intron-1 of the para Voltage-Gated Sodium Channel gene, a species-diagnostic nucleotide position throughout most of A. coluzzii and A. gambiae sympatric range. We also analyzed polymorphism in the thioester-binding domain (TED) of the innate immunity-linked thioester-containing protein 1 (TEP1) to investigate whether elevated hybridization might facilitate the exchange of variants linked to adaptive immunity and Plasmodium refractoriness. Our results confirm asymmetric introgression of genetic material from A. coluzzii to A. gambiae and disruption of linkage between the centromeric "genomic islands" of inter-specific divergence. We report that A. gambiae from the Guinean hybrid zone possesses an introgressed TEP1 resistant allelic class, found exclusively in A. coluzzii elsewhere and apparently swept to fixation in West Africa (i.e. Mali and Burkina Faso). However, no detectable fixation of this allele was found in Guinea Bissau, which may suggest that ecological pressures driving segregation between the two species in larval habitats in this region may be different from those experienced in northern and more arid parts of the species’ range. Finally, our results also suggest a genetic subdivision between coastal and inland A. gambiae Guinean populations and provide clues on the importance of ecological factors in intra-specific differentiation processes.
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11
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Lee Y, Weakley AM, Nieman CC, Malvick J, Lanzaro GC. A multi-detection assay for malaria transmitting mosquitoes. J Vis Exp 2015:e52385. [PMID: 25867057 DOI: 10.3791/52385] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The Anopheles gambiae species complex includes the major malaria transmitting mosquitoes in Africa. Because these species are of such medical importance, several traits are typically characterized using molecular assays to aid in epidemiological studies. These traits include species identification, insecticide resistance, parasite infection status, and host preference. Since populations of the Anopheles gambiae complex are morphologically indistinguishable, a polymerase chain reaction (PCR) is traditionally used to identify species. Once the species is known, several downstream assays are routinely performed to elucidate further characteristics. For instance, mutations known as KDR in a para gene confer resistance against DDT and pyrethroid insecticides. Additionally, enzyme-linked immunosorbent assays (ELISAs) or Plasmodium parasite DNA detection PCR assays are used to detect parasites present in mosquito tissues. Lastly, a combination of PCR and restriction enzyme digests can be used to elucidate host preference (e.g., human vs. animal blood) by screening the mosquito bloodmeal for host-specific DNA. We have developed a multi-detection assay (MDA) that combines all of the aforementioned assays into a single multiplex reaction genotyping 33SNPs for 96 or 384 samples at a time. Because the MDA includes multiple markers for species, Plasmodium detection, and host blood identification, the likelihood of generating false positives or negatives is greatly reduced from previous assays that include only one marker per trait. This robust and simple assay can detect these key mosquito traits cost-effectively and in a fraction of the time of existing assays.
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Affiliation(s)
- Yoosook Lee
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California - Davis;
| | - Allison M Weakley
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California - Davis
| | - Catelyn C Nieman
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California - Davis
| | - Julia Malvick
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis
| | - Gregory C Lanzaro
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California - Davis
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12
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Santolamazza F, Caputo B, Nwakanma DC, Fanello C, Petrarca V, Conway DJ, Weetman D, Pinto J, Mancini E, della Torre A. Remarkable diversity of intron-1 of the para voltage-gated sodium channel gene in an Anopheles gambiae/Anopheles coluzzii hybrid zone. Malar J 2015; 14:9. [PMID: 25604888 PMCID: PMC4308935 DOI: 10.1186/s12936-014-0522-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 12/20/2014] [Indexed: 11/26/2022] Open
Abstract
Background Genomic differentiation between Anopheles gambiae and Anopheles coluzzii - the major malaria vectors in sub-Saharan Africa - is localized into large “islands” toward the centromeres of chromosome-X and the two autosomes. Linkage disequilibrium between these genomic islands was first detected between species-specific polymorphisms within ribosomal DNA genes (IGS-rDNA) on the X-chromosome and a single variant at position 702 of intron 1 (Int-1702) of the para Voltage-Gated Sodium Channel (VGSC) gene on chromosome arm 2 L. Intron-1 sequence data from West and Central Africa revealed two clearly distinct and species-specific haplogroups, each characterized by very low polymorphism, which has been attributed to a selective sweep. The aim of this study was to analyse Int-1 sequence diversity in A. gambiae and A. coluzzii populations from the Far-West of their range, in order to assess whether this selective-sweep signature could persist in a zone of high interspecific hybridization. Methods A 531 bp region of VGSC Int-1 was sequenced in 21 A. coluzzii, 31 A. gambiae, and 12 hybrids from The Gambia and Guinea Bissau, located within the Far-West geographical region, and in 53 A. gambiae s.l. samples from the rest of the range. Results Far-West samples exhibit dramatic Int-1 polymorphism, far higher within each country than observed throughout the rest of the species range. Moreover, patterning of haplotypes within A. coluzzii confirms previous evidence of a macro-geographic subdivision into a West and a Central African genetic cluster, and reveals a possible genetic distinction of A. coluzzii populations from the Far-West. Conclusions The results suggest a relaxation of selective pressures acting across the VGSC gene region in the hybrid zone. Genetic differentiation in the Far-West could be attributable to a founder effect within A. coluzzii, with subsequent extensive gene flow with secondarily-colonizing A. gambiae, potentially yielding a novel insight on the dynamic processes impacting genetic divergence of these key malaria vectors. Electronic supplementary material The online version of this article (doi:10.1186/s12936-014-0522-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Emiliano Mancini
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur-Fondazione Cenci-Bolognetti, Università "Sapienza", Piazzale Aldo Moro 5, Rome, 00185, Italy.
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13
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Gordicho V, Vicente JL, Sousa CA, Caputo B, Pombi M, Dinis J, Seixas G, Palsson K, Weetman D, Rodrigues A, della Torre A, Pinto J. First report of an exophilic Anopheles arabiensis population in Bissau City, Guinea-Bissau: recent introduction or sampling bias? Malar J 2014; 13:423. [PMID: 25370807 PMCID: PMC4240859 DOI: 10.1186/1475-2875-13-423] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 10/25/2014] [Indexed: 11/23/2022] Open
Abstract
Background The malaria vector Anopheles arabiensis exhibits greater behavioural and ecological plasticity than the other major vectors of the Anopheles gambiae complex, which presents challenges for major control methods. This study reports for the first time the presence of An. arabiensis in Antula, a suburb of Bissau city, the capital of Guinea Bissau, where high levels of hybridization between Anopheles coluzzii and An. gambiae have been reported. Given that previous surveys in the area, based on indoor collections, did not sample An. arabiensis, the possibility of a recently introduced exophilic population was investigated. Methods Larval and adult mosquito collections were carried out in Antula at the end of the rainy season of 2010. Anopheles gambiae species composition, determined by rDNA-IGS and SINE200X6.1 markers, was compared with four previously collected samples dating back to 1993. Analysis of ten microsatellites was used to estimate levels of genetic diversity, relatedness and to investigate demographic stability. Results Anopheles arabiensis comprised 54.0% of larvae and 25.6% of adults collected in 2010, but was absent in all previous collections, a highly unlikely observation by chance if the population was stable. This species had the lowest levels of genetic diversity, highest relatedness and, along with An. gambiae, exhibited evidence of a recent population expansion. Conclusions Results point to the presence of a previously undetected outdoor population of An. arabiensis in Antula, which appears to have expanded recently, highlighting the importance of complementing indoor-based mosquito collections with sampling methods targeting outdoor adults and immature stages for a more complete assessment of mosquito biodiversity. A change in temporal dynamics in the species complex composition was also detected. Coupled with previous evidence of asymmetric introgression from An. coluzzii to An. gambiae, this suggests that the study area may be subject to ecological changes with a potential impact on both the genetics of these species and on malaria transmission. Electronic supplementary material The online version of this article (doi:10.1186/1475-2875-13-423) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - João Pinto
- UEI Parasitologia Médica, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008 Lisbon, Portugal.
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Garros C, Balenghien T, Carpenter S, Delécolle JC, Meiswinkel R, Pédarrieu A, Rakotoarivony I, Gardès L, Golding N, Barber J, Miranda M, Borràs DB, Goffredo M, Monaco F, Pagès N, Sghaier S, Hammami S, Calvo JH, Lucientes J, Geysen D, De Deken G, Sarto I Monteys V, Schwenkenbecher J, Kampen H, Hoffmann B, Lehmann K, Werner D, Baldet T, Lancelot R, Cêtre-Sossah C. Towards the PCR-based identification of Palaearctic Culicoides biting midges (Diptera: Ceratopogonidae): results from an international ring trial targeting four species of the subgenus Avaritia. Parasit Vectors 2014; 7:223. [PMID: 24884950 PMCID: PMC4024274 DOI: 10.1186/1756-3305-7-223] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 04/28/2014] [Indexed: 01/11/2023] Open
Abstract
Background Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are biological vectors of internationally important arboviruses. To understand the role of Culicoides in the transmission of these viruses, it is essential to correctly identify the species involved. Within the western Palaearctic region, the main suspected vector species, C. obsoletus, C. scoticus, C. dewulfi and C. chiopterus, have similar wing patterns, which makes it difficult to separate and identify them correctly. Methods In this study, designed as an inter-laboratory ring trial with twelve partners from Europe and North Africa, we assess four PCR-based assays which are used routinely to differentiate the four species of Culicoides listed above. The assays based on mitochondrial or ribosomal DNA or microarray hybridisation were tested using aliquots of Culicoides DNA (extracted using commercial kits), crude lysates of ground specimens and whole Culicoides (265 individuals), and non-Culicoides Ceratopogonidae (13 individuals) collected from across Europe. Results A total of 800 molecular assays were implemented. The in-house assays functioned effectively, although specificity and sensitivity varied according to the molecular marker and DNA extraction method used. The Obsoletus group specificity was overall high (95-99%) while the sensitivity varied greatly (59.6-100%). DNA extraction methods impacted the sensitivity of the assays as well as the type of sample used as template for the DNA extraction. Conclusions The results are discussed in terms of current use of species diagnostic assays and the future development of molecular tools for the rapid differentiation of cryptic Culicoides species.
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Lee Y, Marsden CD, Nieman C, Lanzaro GC. A new multiplex SNP genotyping assay for detecting hybridization and introgression between the M and S molecular forms of Anopheles gambiae. Mol Ecol Resour 2013; 14:297-305. [PMID: 24119184 DOI: 10.1111/1755-0998.12181] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 09/20/2013] [Accepted: 09/25/2013] [Indexed: 11/29/2022]
Abstract
The M and S forms of Anopheles gambiae have been the subject of intense study, but are morphologically indistinguishable and can only be identified using molecular techniques. PCR-based assays to distinguish the two forms have been designed and applied widely. However, the application of these assays towards identifying hybrids between the two forms, and backcrossed hybrids in particular, has been problematic as the currently available diagnostic assays are based on single locus and/or are located within a multicopy gene. Here, we present an alternative genotyping method for detecting hybridization and introgression between M and S molecular forms based on a multilocus panel of single-nucleotide polymorphisms (SNPs) fixed between the M and S forms. The panel of SNPs employed is located in so-called islands of divergence leading us to describe this method as the 'Divergence Island SNP' (DIS) assay. We show this multilocus SNP genotyping approach can robustly and accurately detect F1 hybrids as well as backcrossed individuals.
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Affiliation(s)
- Yoosook Lee
- Vector Genetics Laboratory, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California - Davis, Davis, CA, 95616, USA
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Sawadogo SP, Costantini C, Pennetier C, Diabaté A, Gibson G, Dabiré RK. Differences in timing of mating swarms in sympatric populations of Anopheles coluzzii and Anopheles gambiae s.s. (formerly An. gambiae M and S molecular forms) in Burkina Faso, West Africa. Parasit Vectors 2013; 6:275. [PMID: 24330578 PMCID: PMC3851435 DOI: 10.1186/1756-3305-6-275] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Accepted: 09/13/2013] [Indexed: 11/27/2022] Open
Abstract
Background The M and S molecular forms of Anopheles gambiae s.s. Giles appear to have speciated in West Africa and the M form is now formally named An. coluzzii Coetzee & Wilkerson sp.n. and the S form retains the nominotypical name (abbreviated here to An. gambiae). Reproductive isolation is thought to be the main barrier to hybridisation; even though both species are found in the same mating swarms, hybrid fertilisations in copulae have not been found in the study area. The aim of the study, therefore, was to determine whether differences in circadian and/or environmental control over the timing of swarming in the two species contribute to reproductive isolation. Methods The timing of male swarming in these species was recorded four nights per month over four years at five swarming sites in each of two villages. The timing of the start and end of swarming, and the concurrent environmental parameters, temperature, humidity and light intensity, were recorded for n = 20 swarms/month/species. The timing of 'spontaneous’ activity at dusk of individual An. coluzzii and An. gambiae males was video-recorded in an actograph outdoors for 21 nights. Results Of the environmental parameters considered, swarming was most strongly correlated with sunset (r2 > 0.946). Anopheles gambiae started and stopped swarming earlier than An. coluzzii (3:35 ± 0:68 min:sec and 4:51 ± 1:21, respectively), and the mean duration of swarming was 23:37 ± 0:33 for An. gambiae and 21:39 ± 0:33 for An. coluzzii. Accordingly, in principle, whenever both species swarm over the same marker, a mean of 15.3 ± 3.1% of An. gambiae swarming would occur before An. coluzzii males arrived, and 19.5 ± 4.55% of An. coluzzii swarming would occurred after An. gambiae males had stopped swarming. These results are consistent with the finding that An. gambiae males became active in the actograph 09:35 ± 00:22 min:sec earlier than An. coluzzii males. Conclusions The timing of swarming and spontaneous activity at dusk are primarily under circadian control, with the phase linked closely to sunset throughout the year. The mating activity of these two species is temporally segregated for 15-20% of the swarming period, which may contribute to the observed reproductive isolation of these species in local sympatric populations.
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Affiliation(s)
| | | | | | | | | | - Roch K Dabiré
- Institut de Recherche en Sciences de la Santé (IRSS)/Centre Muraz, Bobo-Dioulasso 01 BP 545, Burkina Faso.
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Dabire KR, Sawadodgo S, Diabate A, Toe KH, Kengne P, Ouari A, Costantini C, Gouagna C, Simard F, Baldet T, Lehmann T, Gibson G. Assortative mating in mixed swarms of the mosquito Anopheles gambiae s.s. M and S molecular forms, in Burkina Faso, West Africa. MEDICAL AND VETERINARY ENTOMOLOGY 2013; 27:298-312. [PMID: 23360106 DOI: 10.1111/j.1365-2915.2012.01049.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The molecular form composition of Anopheles gambiae Giles s.s. (Diptera: Culicidae) mating swarms and the associated mating pairs (copulae) were investigated during two rainy seasons (July to October, 2005 and July to November, 2006) in the villages of Soumousso and Vallée du Kou (VK7). Although the habitats of these villages differ markedly, sympatric populations of M and S molecular forms of An. gambiae s.s. occur in both places periodically. The main aim was to assess the degree to which these molecular forms mate assortatively. In Soumousso, a wooded savannah habitat, the majority of swarm samples consisted of only S-form males (21/28), although a few M-form males were found in mixed M- and S-form swarms. In VK7, a rice growing area, the majority of swarm samples consisted of only M-form males (38/62), until October and November 2006, when there were nearly as many mixed-form as single-form swarms. Overall, ∼60% of M- and S-form swarms were temporally or spatially segregated; the two forms were effectively prevented from encountering each other. Of the remaining 40% of swarms, however, only about half were single-form and the rest were mixed-form. Of the 33 copulae collected from mixed-form swarms, only four were mixed-form pairs, significantly fewer than expected by random pairing between forms (χ(2) = 10.34, d.f. = 2, P < 0.01). Finally, all specimens of inseminated females were of the same form as the sperm contained within their spermatheca (n = 91), even for the four mixed-form copulae. These findings indicate that assortative mating occurs within mixed-form swarms, mediated most probably by close-range mate recognition cues.
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Affiliation(s)
- K R Dabire
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, West Africa.
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Müller P, Pflüger V, Wittwer M, Ziegler D, Chandre F, Simard F, Lengeler C. Identification of cryptic Anopheles mosquito species by molecular protein profiling. PLoS One 2013; 8:e57486. [PMID: 23469000 PMCID: PMC3585343 DOI: 10.1371/journal.pone.0057486] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 01/21/2013] [Indexed: 11/18/2022] Open
Abstract
Vector control is the mainstay of malaria control programmes. Successful vector control profoundly relies on accurate information on the target mosquito populations in order to choose the most appropriate intervention for a given mosquito species and to monitor its impact. An impediment to identify mosquito species is the existence of morphologically identical sibling species that play different roles in the transmission of pathogens and parasites. Currently PCR diagnostics are used to distinguish between sibling species. PCR based methods are, however, expensive, time-consuming and their development requires a priori DNA sequence information. Here, we evaluated an inexpensive molecular proteomics approach for Anopheles species: matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). MALDI-TOF MS is a well developed protein profiling tool for the identification of microorganisms but so far has received little attention as a diagnostic tool in entomology. We measured MS spectra from specimens of 32 laboratory colonies and 2 field populations representing 12 Anopheles species including the A. gambiae species complex. An important step in the study was the advancement and implementation of a bioinformatics approach improving the resolution over previously applied cluster analysis. Borrowing tools for linear discriminant analysis from genomics, MALDI-TOF MS accurately identified taxonomically closely related mosquito species, including the separation between the M and S molecular forms of A. gambiae sensu stricto. The approach also classifies specimens from different laboratory colonies; hence proving also very promising for its use in colony authentication as part of quality assurance in laboratory studies. While being exceptionally accurate and robust, MALDI-TOF MS has several advantages over other typing methods, including simple sample preparation and short processing time. As the method does not require DNA sequence information, data can also be reviewed at any later stage for diagnostic or functional patterns without the need for re-designing and re-processing biological material.
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Affiliation(s)
- Pie Müller
- Department of Medical Services and Diagnostic, Swiss Tropical and Public Health Institute, Basel, Switzerland.
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19
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Abstract
Understanding genetic causes and effects of speciation in sympatric populations of sexually reproducing eukaryotes is challenging, controversial, and of practical importance for controlling rapidly evolving pests and pathogens. The major African malaria vector mosquito Anopheles gambiae sensu stricto (s.s.) is considered to contain two incipient species with strong reproductive isolation, hybrids between the M and S molecular forms being very rare. Following recent observations of higher proportions of hybrid forms at a few sites in West Africa, we conducted new surveys of 12 sites in four contiguous countries (The Gambia, Senegal, Guinea-Bissau, and Republic of Guinea). Identification and genotyping of 3499 A. gambiae s.s. revealed high frequencies of M/S hybrid forms at each site, ranging from 5 to 42%, and a large spectrum of inbreeding coefficient values from 0.11 to 0.76, spanning most of the range expected between the alternative extremes of panmixia and assortative mating. Year-round sampling over 2 years at one of the sites in The Gambia showed that M/S hybrid forms had similar relative frequencies throughout periods of marked seasonal variation in mosquito breeding and abundance. Genome-wide scans with an Affymetrix high-density single-nucleotide polymorphism (SNP) microarray enabled replicate comparisons of pools of different molecular forms, in three separate populations. These showed strong differentiation between M and S forms only in the pericentromeric region of the X chromosome that contains the molecular form-specific marker locus, with only a few other loci showing minor differences. In the X chromosome, the M/S hybrid forms were more differentiated from M than from S forms, supporting a hypothesis of asymmetric introgression and backcrossing.
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Fryxell RTT, Nieman CC, Fofana A, Lee Y, Traoré SF, Cornel AJ, Luckhart S, Lanzaro GC. Differential Plasmodium falciparum infection of Anopheles gambiae s.s. molecular and chromosomal forms in Mali. Malar J 2012; 11:133. [PMID: 22540973 PMCID: PMC3441388 DOI: 10.1186/1475-2875-11-133] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 04/27/2012] [Indexed: 12/18/2022] Open
Abstract
Background Anopheles gambiae sensu stricto (s.s.) is a primary vector of Plasmodium falciparum in sub-Saharan Africa. Although some physiological differences among molecular and chromosomal forms of this species have been demonstrated, the relative susceptibility to malaria parasite infection among them has not been unequivocally shown. The objective of this study was to investigate P. falciparum circumsporozoite protein infection (CSP) positivity among An. gambiae s.s. chromosomal and molecular forms. Methods Wild An. gambiae from two sites Kela (n = 464) and Sidarebougou (n = 266) in Mali were screened for the presence of P. falciparum CSP using an enzyme-linked immunosorbent assay (ELISA). Samples were then identified to molecular form using multiple PCR diagnostics (n = 713) and chromosomal form using chromosomal karyotyping (n = 419). Results Of 730 An. gambiae sensu lato (s.l.) mosquitoes, 89 (12.2%) were CSP ELISA positive. The percentage of positive mosquitoes varied by site: 52 (11.2%) in Kela and 37 (13.9%) in Sidarebougou. Eighty-seven of the positive mosquitoes were identified to molecular form and they consisted of nine Anopheles arabiensis (21.4%), 46 S (10.9%), 31 M (12.8%), and one MS hybrid (14.3%). Sixty of the positive mosquitoes were identified to chromosomal form and they consisted of five An. arabiensis (20.0%), 21 Savanna (15.1%), 21 Mopti (30.4%), 11 Bamako (9.2%), and two hybrids (20.0%). Discussion In this collection, the prevalence of P. falciparum infection in the M form was equivalent to infection in the S form (no molecular form differential infection). There was a significant differential infection by chromosomal form such that, P. falciparum infection was more prevalent in the Mopti chromosomal forms than in the Bamako or Savanna forms; the Mopti form was also the most underrepresented in the collection. Continued research on the differential P. falciparum infection of An. gambiae s.s. chromosomal and molecular forms may suggest that Plasmodium – An. gambiae interactions play a role in malaria transmission.
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Affiliation(s)
- Rebecca T Trout Fryxell
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, 37996, USA.
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