1
|
Laojun S, Changbunjong T, Chaiphongpachara T. Insights into the mitochondrial cytochrome oxidase I (mt-COI) gene and wing morphometrics of Anopheles baimaii (Diptera: Culicidae) in malaria-endemic islands of Thailand. Parasitol Res 2024; 123:171. [PMID: 38530429 DOI: 10.1007/s00436-024-08195-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 03/21/2024] [Indexed: 03/28/2024]
Abstract
Anopheles baimaii (Diptera: Culicidae) significantly contributes to the transmission of parasites causing malaria in Southeast Asia and South Asia. This study examined the morphological (wing shape) and molecular (mitochondrial gene) variations of An. baimaii in four of Thailand's border islands, and also investigated the presence of Plasmodium parasites in these mosquitoes. No Plasmodium infections were detected in the samples. Significant differences in wing shape were observed in most island populations (p < 0.05). A single-linkage tree, constructed using Mahalanobis distances, clustered the populations into two groups based on geographical locations. Genetic variation in An. baimaii was also analyzed through cytochrome c oxidase subunit I (COI) gene sequences. This analysis identified 22 segregating sites and a low nucleotide diversity of 0.004. Furthermore, 18 distinct haplotypes were identified, indicating a high haplotype diversity of 0.825. Neutrality tests for the overall population revealed a significantly negative Fu's Fs value (-5.029), indicating a population expansion. In contrast, Tajima's D yielded a negative value (-1.028) that did not reach statistical significance. The mismatch distribution analysis exhibited a bimodal pattern, and the raggedness index was 0.068, showing no significant discrepancy (p = 0.485) between observed and expected distributions. Pairwise genetic differentiation assessments demonstrated significant differences between all populations (p < 0.05). These findings provide valuable insights into the COI gene and wing morphometric variations in An. baimaii across Thailand's islands, offering critical information for understanding the adaptations of this malaria vector and guiding future comprehensive research.
Collapse
Affiliation(s)
- Sedthapong Laojun
- Department of Public Health and Health Promotion, College of Allied Health Sciences, Suan Sunandha Rajabhat University, Samut Songkhram, 75000, Thailand
| | - Tanasak Changbunjong
- Department of Pre-Clinic and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
- The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals (MoZWE), Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Tanawat Chaiphongpachara
- Department of Public Health and Health Promotion, College of Allied Health Sciences, Suan Sunandha Rajabhat University, Samut Songkhram, 75000, Thailand.
| |
Collapse
|
2
|
Mustafa MSEK, Jaal Z, Abu Kashawa S, Mohd Nor SA. Population genetics of Anopheles arabiensis, the primary malaria vector in the Republic of Sudan. Malar J 2021; 20:469. [PMID: 34923983 PMCID: PMC8684682 DOI: 10.1186/s12936-021-03994-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 11/25/2021] [Indexed: 11/16/2022] Open
Abstract
Background Anopheles arabiensis is a member of Anopheles gambiae complex and the main malaria vector in Sudan. There is insufficient population genetics data available on An. arabiensis for an understanding of vector population structure and genetics, which are important for the malaria vector control programmes in this country. The objective of this investigation is to study the population structure, gene flow and isolation by distance among An. arabiensis populations for developing control strategies. Methods Mosquitoes were collected from six sites located in three different states in Sudan, Khartoum, Kassala and Sennar, using pyrethrum spray catch of indoor resting mosquitoes. Anopheline mosquitoes were identified morphologically and based on species specific nucleotide sequences in the ribosomal DNA intergenic spacers (IGS). Seven published An. gambiae microsatellite loci primers were used to amplify the DNA of An. arabiensis samples. Results PCR confirmed that An. arabiensis was the main malaria vector found in the six localities. Of the seven microsatellite loci utilized, six were found to be highly polymorphic across populations, with high allelic richness and heterozygosity with the remaining one being monomorphic. Deviation from Hardy–Weinberg expectations were found in 21 out of 42 tests in the six populations due to heterozygote deficiency. Bayesian clustering analysis revealed two gene pools, grouping samples into two population clusters; one includes four and the other includes two populations. The clusters were not grouped according to the three states but were instead an admixture. The genetic distances between pairs of populations ranged from 0.06 to 0.24. Significant FST was observed between all pairwise analyses of An. arabiensis populations. The Kassala state population indicated high genetic differentiation (FST ranged from 0.17 to 0.24) from other populations, including one which is also located in the same state. High gene flow (Nm = 1.6–8.2) was detected among populations within respective clusters but limited between clusters particularly with respect to Kassala state. There was evidence of a bottleneck event in one of the populations (Al Haj Yousif site). No isolation by distance pattern was detected among populations. Conclusions This study revealed low levels of population differentiation with high gene flow among the An. arabiensis populations investigated in Sudan, with the exception of Kassala state.
Collapse
Affiliation(s)
| | - Zairi Jaal
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia
| | - Sumia Abu Kashawa
- Faculty of Science, Department of Zoology, University of Khartoum, Khartoum, Sudan
| | - Siti Azizah Mohd Nor
- Institute of Marine Biotechnology, Universiti Malaysia Terengganu, 21030, Kuala Terengganu, Malaysia
| |
Collapse
|
3
|
Lanzaro GC, Campos M, Crepeau M, Cornel A, Estrada A, Gripkey H, Haddad Z, Kormos A, Palomares S. Selection of sites for field trials of genetically engineered mosquitoes with gene drive. Evol Appl 2021; 14:2147-2161. [PMID: 34603489 PMCID: PMC8477601 DOI: 10.1111/eva.13283] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/29/2021] [Accepted: 07/06/2021] [Indexed: 12/11/2022] Open
Abstract
Novel malaria control strategies using genetically engineered mosquitoes (GEMs) are on the horizon. Population modification is one approach wherein mosquitoes are engineered with genes rendering them refractory to the malaria parasite, Plasmodium falciparum, coupled with a low-threshold, Cas9-based gene drive. When released into a wild vector population, GEMs preferentially transmit these parasite-blocking genes to their offspring, ultimately modifying a vector population into a nonvector one. Deploying this technology awaits ecologically contained field trial evaluations. Here, we consider a process for site selection, the first critical step in designing a trial. Our goal is to identify a site that maximizes prospects for success, minimizes risk, and serves as a fair, valid, and convincing test of efficacy and impacts of a GEM product intended for large-scale deployment in Africa. We base site selection on geographic, geological, and biological, rather than social or legal, criteria. We recognize the latter as critically important but not as a first step in selecting a site. We propose physical islands as being the best candidates for a GEM field trial and present an evaluation of 22 African islands. We consider geographic and genetic isolation, biological complexity, island size, and topography and identify two island groups that satisfy key criteria for ideal GEM field trial sites.
Collapse
Affiliation(s)
- Gregory C. Lanzaro
- Vector Genetics LaboratoryDepartment of Pathology, Microbiology and ImmunologySchool of Veterinary MedicineUniversity of CaliforniaDavisCaliforniaUSA
| | - Melina Campos
- Vector Genetics LaboratoryDepartment of Pathology, Microbiology and ImmunologySchool of Veterinary MedicineUniversity of CaliforniaDavisCaliforniaUSA
| | - Marc Crepeau
- Vector Genetics LaboratoryDepartment of Pathology, Microbiology and ImmunologySchool of Veterinary MedicineUniversity of CaliforniaDavisCaliforniaUSA
| | - Anthony Cornel
- Vector Genetics LaboratoryDepartment of Pathology, Microbiology and ImmunologySchool of Veterinary MedicineUniversity of CaliforniaDavisCaliforniaUSA
| | - Abram Estrada
- Vector Genetics LaboratoryDepartment of Pathology, Microbiology and ImmunologySchool of Veterinary MedicineUniversity of CaliforniaDavisCaliforniaUSA
| | - Hans Gripkey
- Vector Genetics LaboratoryDepartment of Pathology, Microbiology and ImmunologySchool of Veterinary MedicineUniversity of CaliforniaDavisCaliforniaUSA
| | - Ziad Haddad
- California Institute of TechnologyJet Propulsion LaboratoryPasadenaCaliforniaUSA
| | - Ana Kormos
- Vector Genetics LaboratoryDepartment of Pathology, Microbiology and ImmunologySchool of Veterinary MedicineUniversity of CaliforniaDavisCaliforniaUSA
| | - Steven Palomares
- Vector Genetics LaboratoryDepartment of Pathology, Microbiology and ImmunologySchool of Veterinary MedicineUniversity of CaliforniaDavisCaliforniaUSA
| |
Collapse
|
4
|
Bergey CM, Lukindu M, Wiltshire RM, Fontaine MC, Kayondo JK, Besansky NJ. Assessing connectivity despite high diversity in island populations of a malaria mosquito. Evol Appl 2020; 13:417-431. [PMID: 31993086 PMCID: PMC6976967 DOI: 10.1111/eva.12878] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/28/2019] [Accepted: 09/27/2019] [Indexed: 12/14/2022] Open
Abstract
Documenting isolation is notoriously difficult for species with vast polymorphic populations. High proportions of shared variation impede estimation of connectivity, even despite leveraging information from many genetic markers. We overcome these impediments by combining classical analysis of neutral variation with assays of the structure of selected variation, demonstrated using populations of the principal African malaria vector Anopheles gambiae. Accurate estimation of mosquito migration is crucial for efforts to combat malaria. Modeling and cage experiments suggest that mosquito gene drive systems will enable malaria eradication, but establishing safety and efficacy requires identification of isolated populations in which to conduct field testing. We assess Lake Victoria islands as candidate sites, finding one island 30 km offshore is as differentiated from mainland samples as populations from across the continent. Collectively, our results suggest sufficient contemporary isolation of these islands to warrant consideration as field-testing locations and illustrate shared adaptive variation as a useful proxy for connectivity in highly polymorphic species.
Collapse
Affiliation(s)
- Christina M. Bergey
- Department of Biological SciencesUniversity of Notre DameNotre DameINUSA
- Eck Institute for Global HealthUniversity of Notre DameNotre DameINUSA
- Department of GeneticsRutgers UniversityPiscatawayNJUSA
- Departments of Anthropology and BiologyPennsylvania State UniversityUniversity ParkPAUSA
| | - Martin Lukindu
- Department of Biological SciencesUniversity of Notre DameNotre DameINUSA
- Eck Institute for Global HealthUniversity of Notre DameNotre DameINUSA
| | - Rachel M. Wiltshire
- Department of Biological SciencesUniversity of Notre DameNotre DameINUSA
- Eck Institute for Global HealthUniversity of Notre DameNotre DameINUSA
| | - Michael C. Fontaine
- Groningen Institute for Evolutionary Life Sciences (GELIFES)University of GroningenGroningenThe Netherlands
- MIVEGECIRDCNRSUniversity of MontpellierMontpellierFrance
| | | | - Nora J. Besansky
- Department of Biological SciencesUniversity of Notre DameNotre DameINUSA
- Eck Institute for Global HealthUniversity of Notre DameNotre DameINUSA
| |
Collapse
|
5
|
Suesdek L. Microevolution of medically important mosquitoes - A review. Acta Trop 2019; 191:162-171. [PMID: 30529448 DOI: 10.1016/j.actatropica.2018.12.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 11/08/2018] [Accepted: 12/06/2018] [Indexed: 12/25/2022]
Abstract
This review intends to discuss central issues regarding the microevolution of mosquito (Culicidae) vectors of several pathogens and how this process impacts vector biology, disease transmission, and vector control attempts. On the microevolutionary context, it comparatively discusses the current knowledge on the population genetics of representatives of the genera Aedes, Anopheles and Culex, and comments on insecticide resistance of culicids. It also discusses other biological aspects of culicids that are not usually addressed in microevolutionary studies, such as vectorial competence, endosymbiosis, and wing morphology. One conclusion is that mosquitoes are highly genetically variable, adaptable, fast evolving, and have versatile vectorial competence. Unveiling microevolutionary patterns is fundamental for the design and maintenance of all control programs. Sampling methods for assessing microevolution must be standardized and must follow meaningful guidelines, such as those of "landscape genetics". A good understanding of microevolution requires more than a collection of case studies on population genetics and resistance. Future research could deal not only with the microevolution sensu stricto, but also with evolutionarily meaningful issues, such as inheritable characters, epigenetics, physiological cost-free plasticity, vector immunity, symbiosis, pathogen-mosquito co-evolution and environmental variables. A genotyping panel for seeking adaptive phenotypes as part of the standardization of population genetics methods is proposed. The investigative paradigm should not only be retrospective but also prospective, despite the unpredictability of evolution. If we integrate all suggestions to tackle mosquito evolution, a global revolution to counter vector-borne diseases can be provoked.
Collapse
|
6
|
Wiltshire RM, Bergey CM, Kayondo JK, Birungi J, Mukwaya LG, Emrich SJ, Besansky NJ, Collins FH. Reduced-representation sequencing identifies small effective population sizes of Anopheles gambiae in the north-western Lake Victoria basin, Uganda. Malar J 2018; 17:285. [PMID: 30081911 PMCID: PMC6080216 DOI: 10.1186/s12936-018-2432-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 07/30/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Malaria is the leading cause of global paediatric mortality in children below 5 years of age. The number of fatalities has reduced significantly due to an expansion of control interventions but the development of new technologies remains necessary in order to achieve elimination. Recent attention has been focused on the release of genetically modified (GM) mosquitoes into natural vector populations as a mechanism of interrupting parasite transmission but despite successful in vivo laboratory studies, a detailed population genetic assessment, which must first precede any proposed field trial, has yet to be undertaken systematically. Here, the genetic structure of Anopheles gambiae populations in north-western Lake Victoria is explored to assess their suitability as candidates for a pilot field study release of GM mosquitoes. METHODS 478 Anopheles gambiae mosquitoes were collected from six locations and a subset (N = 96) was selected for restriction site-associated DNA sequencing (RADseq). The resulting single nucleotide polymorphism (SNP) marker set was analysed for effective size (Ne), connectivity and population structure (PCA, FST). RESULTS 5175 high-quality genome-wide SNPs were identified. A principal components analysis (PCA) of the collinear genomic regions illustrated that individuals clustered in concordance with geographic origin with some overlap between sites. Genetic differentiation between populations was varied with inter-island comparisons having the highest values (median FST 0.0480-0.0846). Ne estimates were generally small (124.2-1920.3). CONCLUSIONS A reduced-representation SNP marker set for genome-wide An. gambiae genetic analysis in the north-western Lake Victoria basin is reported. Island populations demonstrated low to moderate genetic differentiation and greater structure suggesting some limitation to migration. Smaller estimates of Ne indicate that an introduced effector transgene will be more susceptible to genetic drift but to ensure that it is driven to fixation a robust gene drive mechanism will likely be needed. These findings, together with their favourable location and suitability for frequent monitoring, indicate that the Ssese Islands contain several candidate field locations, which merit further evaluation as potential GM mosquito pilot release sites.
Collapse
Affiliation(s)
- Rachel M Wiltshire
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA.
| | - Christina M Bergey
- Departments of Anthropology and Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Jonathan K Kayondo
- Division of Entomology and Vector Biology, Uganda Virus Research Institute, Plot No. 51-59, Nakiwogo Road, Entebbe 49, Uganda
| | - Josephine Birungi
- Division of Entomology and Vector Biology, Uganda Virus Research Institute, Plot No. 51-59, Nakiwogo Road, Entebbe 49, Uganda
| | - Louis G Mukwaya
- Division of Entomology and Vector Biology, Uganda Virus Research Institute, Plot No. 51-59, Nakiwogo Road, Entebbe 49, Uganda
| | - Scott J Emrich
- Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN, 37996, USA
| | - Nora J Besansky
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Frank H Collins
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA
| |
Collapse
|
7
|
James S, Collins FH, Welkhoff PA, Emerson C, Godfray HCJ, Gottlieb M, Greenwood B, Lindsay SW, Mbogo CM, Okumu FO, Quemada H, Savadogo M, Singh JA, Tountas KH, Touré YT. Pathway to Deployment of Gene Drive Mosquitoes as a Potential Biocontrol Tool for Elimination of Malaria in Sub-Saharan Africa: Recommendations of a Scientific Working Group †. Am J Trop Med Hyg 2018; 98:1-49. [PMID: 29882508 PMCID: PMC5993454 DOI: 10.4269/ajtmh.18-0083] [Citation(s) in RCA: 129] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 04/04/2018] [Indexed: 12/22/2022] Open
Abstract
Gene drive technology offers the promise for a high-impact, cost-effective, and durable method to control malaria transmission that would make a significant contribution to elimination. Gene drive systems, such as those based on clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein, have the potential to spread beneficial traits through interbreeding populations of malaria mosquitoes. However, the characteristics of this technology have raised concerns that necessitate careful consideration of the product development pathway. A multidisciplinary working group considered the implications of low-threshold gene drive systems on the development pathway described in the World Health Organization Guidance Framework for testing genetically modified (GM) mosquitoes, focusing on reduction of malaria transmission by Anopheles gambiae s.l. mosquitoes in Africa as a case study. The group developed recommendations for the safe and ethical testing of gene drive mosquitoes, drawing on prior experience with other vector control tools, GM organisms, and biocontrol agents. These recommendations are organized according to a testing plan that seeks to maximize safety by incrementally increasing the degree of human and environmental exposure to the investigational product. As with biocontrol agents, emphasis is placed on safety evaluation at the end of physically confined laboratory testing as a major decision point for whether to enter field testing. Progression through the testing pathway is based on fulfillment of safety and efficacy criteria, and is subject to regulatory and ethical approvals, as well as social acceptance. The working group identified several resources that were considered important to support responsible field testing of gene drive mosquitoes.
Collapse
Affiliation(s)
- Stephanie James
- Foundation for the National Institutes of Health, Bethesda, Maryland
| | | | | | | | | | - Michael Gottlieb
- Foundation for the National Institutes of Health, Bethesda, Maryland
| | - Brian Greenwood
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | | | - Fredros O. Okumu
- Ifakara Health Institute, Ifakara, Tanzania
- University of Glasgow, Glasgow, Scotland
- University of the Witwatersrand, Johannesburg, South Africa
| | - Hector Quemada
- Donald Danforth Plant Science Center, Saint Louis, Missouri
| | - Moussa Savadogo
- New Partnership for Africa’s Development, Ouagadougou, Burkina Faso
| | - Jerome A. Singh
- Centre for the AIDS Programme of Research in South Africa, Durban, KwaZulu-Natal, South Africa
| | - Karen H. Tountas
- Foundation for the National Institutes of Health, Bethesda, Maryland
| | - Yeya T. Touré
- University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| |
Collapse
|
8
|
Lukindu M, Bergey CM, Wiltshire RM, Small ST, Bourke BP, Kayondo JK, Besansky NJ. Spatio-temporal genetic structure of Anopheles gambiae in the Northwestern Lake Victoria Basin, Uganda: implications for genetic control trials in malaria endemic regions. Parasit Vectors 2018; 11:246. [PMID: 29661226 PMCID: PMC5902950 DOI: 10.1186/s13071-018-2826-4] [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: 01/08/2018] [Accepted: 03/28/2018] [Indexed: 11/30/2022] Open
Abstract
Background Understanding population genetic structure in the malaria vector Anopheles gambiae (s.s.) is crucial to inform genetic control and manage insecticide resistance. Unfortunately, species characteristics such as high nucleotide diversity, large effective population size, recent range expansion, and high dispersal ability complicate the inference of genetic structure across its range in sub-Saharan Africa. The ocean, along with the Great Rift Valley, is one of the few recognized barriers to gene flow in this species, but the effect of inland lakes, which could be useful sites for initial testing of genetic control strategies, is relatively understudied. Here we examine Lake Victoria as a barrier between the Ugandan mainland and the Ssese Islands, which lie up to 60 km offshore. We use mitochondrial DNA (mtDNA) from populations sampled in 2002, 2012 and 2015, and perform Bayesian cluster analysis on mtDNA combined with microsatellite data previously generated from the same 2002 mosquito DNA samples. Results Hierarchical analysis of molecular variance and Bayesian clustering support significant differentiation between the mainland and lacustrine islands. In an mtDNA haplotype network constructed from this and previous data, haplotypes are shared even between localities separated by the Rift Valley, a result that more likely reflects retention of shared ancestral polymorphism than contemporary gene flow. Conclusions The relative genetic isolation of An. gambiae on the Ssese Islands, their small size, level terrain and ease of access from the mainland, the relative simplicity of the vectorial system, and the prevalence of malaria, are all attributes that recommend these islands as possible sites for the testing of genetic control strategies.
Collapse
Affiliation(s)
- Martin Lukindu
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Christina M Bergey
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Rachel M Wiltshire
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Scott T Small
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Brian P Bourke
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Jonathan K Kayondo
- Department of Entomology, Uganda Virus Research Institute (UVRI), Entebbe, Uganda
| | - Nora J Besansky
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA.
| |
Collapse
|
9
|
Maliti D, Ranson H, Magesa S, Kisinza W, Mcha J, Haji K, Killeen G, Weetman D. Islands and stepping-stones: comparative population structure of Anopheles gambiae sensu stricto and Anopheles arabiensis in Tanzania and implications for the spread of insecticide resistance. PLoS One 2014; 9:e110910. [PMID: 25353688 PMCID: PMC4212992 DOI: 10.1371/journal.pone.0110910] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 09/08/2014] [Indexed: 11/21/2022] Open
Abstract
Population genetic structures of the two major malaria vectors Anopheles gambiae s.s. and An. arabiensis, differ markedly across Sub-Saharan Africa, which could reflect differences in historical demographies or in contemporary gene flow. Elucidation of the degree and cause of population structure is important for predicting the spread of genetic traits such as insecticide resistance genes or artificially engineered genes. Here the population genetics of An. gambiae s.s. and An. arabiensis in the central, eastern and island regions of Tanzania were compared. Microsatellite markers were screened in 33 collections of female An. gambiae s.l., originating from 22 geographical locations, four of which were sampled in two or three years between 2008 and 2010. An. gambiae were sampled from six sites, An. arabiensis from 14 sites, and both species from two sites, with an additional colonised insectary sample of each species. Frequencies of the knock-down resistance (kdr) alleles 1014S and 1014F were also determined. An. gambiae exhibited relatively high genetic differentiation (average pairwise FST = 0.131), significant even between nearby samples, but without clear geographical patterning. In contrast, An. arabiensis exhibited limited differentiation (average FST = 0.015), but strong isolation-by-distance (Mantel test r = 0.46, p = 0.0008). Most time-series samples of An. arabiensis were homogeneous, suggesting general temporal stability of the genetic structure. An. gambiae populations from Dar es Salaam and Bagamoyo were found to have high frequencies of kdr 1014S (around 70%), with almost 50% homozygote but was at much lower frequency on Unguja Island, with no. An. gambiae population genetic differentiation was consistent with an island model of genetic structuring with highly restricted gene flow, contrary to An. arabiensis which was consistent with a stepping-stone model of extensive, but geographically-restricted gene flow.
Collapse
Affiliation(s)
- Deodatus Maliti
- Ifakara Health Institute, Environmental Health and Ecological Sciences Thematic Group, Ifakara, Morogoro, United Republic of Tanzania
- University of Glasgow, Institute of Biodiversity Animal Health and Comparative Medicine, Glasgow, Lancashire, United Kingdom
| | - Hilary Ranson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Merseyside, Liverpool, United Kingdom
| | - Stephen Magesa
- RTI International, Global Health Division, Dar es Salaam, United Republic of Tanzania
| | - William Kisinza
- National Institute for Medical Research, Amani Research Center, Muheza, Tanga, United Republic of Tanzania
| | - Juma Mcha
- Zanzibar Malaria Elimination Programme, Unguja, Zanzibar, United Republic of Tanzania
| | - Khamis Haji
- Zanzibar Malaria Elimination Programme, Unguja, Zanzibar, United Republic of Tanzania
| | - Gerald Killeen
- Ifakara Health Institute, Environmental Health and Ecological Sciences Thematic Group, Ifakara, Morogoro, United Republic of Tanzania
- Department of Vector Biology, Liverpool School of Tropical Medicine, Merseyside, Liverpool, United Kingdom
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Merseyside, Liverpool, United Kingdom
| |
Collapse
|
10
|
O'Loughlin SM, Magesa S, Mbogo C, Mosha F, Midega J, Lomas S, Burt A. Genomic analyses of three malaria vectors reveals extensive shared polymorphism but contrasting population histories. Mol Biol Evol 2014; 31:889-902. [PMID: 24408911 PMCID: PMC3969563 DOI: 10.1093/molbev/msu040] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Anopheles gambiae s.l. are important malaria vectors, but little is known about their genomic variation in the wild. Here, we present inter- and intraspecies analysis of genome-wide RADseq data, in three Anopheles gambiae s.l. species collected from East Africa. The mosquitoes fall into three genotypic clusters representing described species (A. gambiae, A. arabiensis, and A. merus) with no evidence of cryptic breeding units. Anopheles merus is the most divergent of the three species, supporting a recent new phylogeny based on chromosomal inversions. Even though the species clusters are well separated, there is extensive shared polymorphism, particularly between A. gambiae and A. arabiensis. Divergence between A. gambiae and A. arabiensis does not vary across the autosomes but is higher in X-linked inversions than elsewhere on X or on the autosomes, consistent with the suggestion that this inversion (or a gene within it) is important in reproductive isolation between the species. The 2La/2L+(a) inversion shows no more evidence of introgression between A. gambiae and A. arabiensis than the rest of the autosomes. Population differentiation within A. gambiae and A. arabiensis is weak over approximately 190-270 km, implying no strong barriers to dispersal. Analysis of Tajima's D and the allele frequency spectrum is consistent with modest population increases in A. arabiensis and A. merus, but a more complex demographic history of expansion followed by contraction in A. gambiae. Although they are less than 200 km apart, the two A. gambiae populations show evidence of different demographic histories.
Collapse
Affiliation(s)
- Samantha M O'Loughlin
- Department of Life Sciences, Imperial College London, Silwood Park, Ascot, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
11
|
Marsden CD, Cornel A, Lee Y, Sanford MR, Norris LC, Goodell PB, Nieman CC, Han S, Rodrigues A, Denis J, Ouledi A, Lanzaro GC. An analysis of two island groups as potential sites for trials of transgenic mosquitoes for malaria control. Evol Appl 2013; 6:706-20. [PMID: 23789035 PMCID: PMC3684749 DOI: 10.1111/eva.12056] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 01/13/2013] [Indexed: 11/29/2022] Open
Abstract
Considerable technological advances have been made towards the generation of genetically modified mosquitoes for vector control. In contrast, less progress has been made towards field evaluations of transformed mosquitoes which are critical for evaluating the success of, and hazards associated with, genetic modification. Oceanic islands have been highlighted as potentially the best locations for such trials. However, population genetic studies are necessary to verify isolation. Here, we used a panel of genetic markers to assess for evidence of genetic isolation of two oceanic island populations of the African malaria vector, Anopheles gambiae s.s. We found no evidence of isolation between the Bijagós archipelago and mainland Guinea-Bissau, despite separation by distances beyond the known dispersal capabilities of this taxon. Conversely, the Comoros Islands appear to be genetically isolated from the East African mainland, and thus represent a location worthy of further investigation for field trials. Based on assessments of gene flow within and between the Comoros islands, the island of Grande Comore was found to be genetically isolated from adjacent islands and also exhibited local population structure, indicating that it may be the most suitable site for trials with existing genetic modification technologies.
Collapse
Affiliation(s)
- Clare D Marsden
- Vector Genetics Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California Davis, CA, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Review of genetic diversity in malaria vectors (Culicidae: Anophelinae). INFECTION GENETICS AND EVOLUTION 2012; 12:1-12. [DOI: 10.1016/j.meegid.2011.08.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 08/05/2011] [Accepted: 08/07/2011] [Indexed: 12/27/2022]
|
13
|
Czeher C, Labbo R, Vieville G, Arzika I, Bogreau H, Rogier C, Diancourt L, Brisse S, Ariey F, Duchemin JB. Population genetic structure of Anopheles gambiae and Anopheles arabiensis in Niger. JOURNAL OF MEDICAL ENTOMOLOGY 2010; 47:355-366. [PMID: 20496583 DOI: 10.1603/me09173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The increasing usage of long-lasting insecticide-treated nets allows protection of millions of people from malaria infection. Monitoring studies should be planned during any wide-scale malaria control program integrating insecticide-treated materials, to evaluate their effects and effectiveness on epidemiologically relevant parameters. Such operational control interventions may be challenged by insecticide resistance spread within vector populations, as a result of wide insecticide pressure. A nationwide distribution of long-lasting insecticidal nets was implemented throughout Niger in 2005. We studied the population genetic structure of major malaria vectors across Nigerien Sahel, and investigated potential effects of this large malaria control intervention. Wild-caught Anopheles gambiae sensu lato females from seven villages and two wet seasons were genotyped at 12 microsatellite loci. The genetic diversity within both species appeared homogenous between villages and years. The estimated genetic differentiation among samples was very low within both species, indicating high gene flow across the area. An absence of differentiation was also found between 2005 and 2006 wet seasons, for all samples but one, showing that the net distribution did not impact significantly the genetic diversity and structure of vector populations in a single year. We provide valuable results participating to document effects of large malaria control programs, to maximize the efficiency of available tools in future interventions.
Collapse
Affiliation(s)
- Cyrille Czeher
- Centre de Recherche Médicale et Sanitaire, Institut Pasteur International Network, Niamey, Niger.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Gutiérrez LA, Naranjo NJ, Cienfuegos AV, Muskus CE, Luckhart S, Conn JE, Correa MM. Population structure analyses and demographic history of the malaria vector Anopheles albimanus from the Caribbean and the Pacific regions of Colombia. Malar J 2009; 8:259. [PMID: 19922672 PMCID: PMC2789746 DOI: 10.1186/1475-2875-8-259] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Accepted: 11/19/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Anopheles albimanus is an important malaria vector in some areas throughout its distribution in the Caribbean and the Pacific regions of Colombia, covering three biogeographic zones of the neotropical region, Maracaibo, Magdalena and Chocó. METHODS This study was conducted to estimate intra-population genetic diversity, genetic differentiation and demographic history of An. albimanus populations because knowledge of vector population structure is a useful tool to guide malaria control programmes. Analyses were based on mtDNA COI gene sequences and four microsatellite loci of individuals collected in eight populations from the Caribbean and the Pacific regions of Colombia. RESULTS Two distinctive groups were consistently detected corresponding to COI haplotypes from each region. A star-shaped statistical parsimony network, significant and unimodal mismatch distribution, and significant negative neutrality tests together suggest a past demographic expansion or a selective sweep in An. albimanus from the Caribbean coast approximately 21,994 years ago during the late Pleistocene. Overall moderate to low genetic differentiation was observed between populations within each region. However, a significant level of differentiation among the populations closer to Buenaventura in the Pacific region was observed. The isolation by distance model best explained genetic differentiation among the Caribbean region localities: Los Achiotes, Santa Rosa de Lima and Moñitos, but it could not explain the genetic differentiation observed between Turbo (Magdalena providence), and the Pacific region localities (Nuquí, Buenaventura, Tumaco). The patterns of differentiation in the populations from the different biogeographic provinces could not be entirely attributed to isolation by distance. CONCLUSION The data provide evidence for limited past gene flow between the Caribbean and the Pacific regions, as estimated by mtDNA sequences and current gene flow patterns among An. albimanus populations as measured by MS loci which may be mainly influenced by semi-permeable natural barriers in each biogeographical region that lead to the genetic differences and effective population sizes detected. The relatively high genetic differentiation in the port city of Buenaventura may be the result of specific ecological conditions, human migration and activities and/or differences in effective population sizes. This knowledge could serve to evaluate and coordinate vector control strategies in these regions of Colombia.
Collapse
Affiliation(s)
- Lina A Gutiérrez
- Grupo de Microbiología Molecular, Escuela de Microbiología, Universidad de Antioquia, Medellín, Colombia.
| | | | | | | | | | | | | |
Collapse
|
15
|
Antonio-Nkondjio C, Ndo C, Kengne P, Mukwaya L, Awono-Ambene P, Fontenille D, Simard F. Population structure of the malaria vector Anopheles moucheti in the equatorial forest region of Africa. Malar J 2008; 7:120. [PMID: 18601716 PMCID: PMC2483286 DOI: 10.1186/1475-2875-7-120] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Accepted: 07/04/2008] [Indexed: 11/17/2022] Open
Abstract
Background Anopheles moucheti is a major malaria vector in forested areas of Africa. However, despite its important epidemiological role, it remains poorly known and insufficiently studied. Here, levels of genetic differentiation were estimated between different A. moucheti populations sampled throughout its distribution range in Central Africa. Methods Polymorphism at ten microsatellite markers was compared in mosquitoes sampled in Cameroon, the Democratic Republic of Congo and an island on Lake Victoria in Uganda. Microsatellite data were used to estimate genetic diversity within populations, their relative long-term effective population size, and the level of genetic differentiation between them. Results All specimens collected in Tsakalakuku (Democratic Republic of Congo) were identified as A. m. bervoetsi while other samples consisted of A. m. moucheti. Successful amplification was obtained at all microsatellite loci within all A. m. moucheti samples while only six loci amplified in A. m. bervoetsi. Allelic richness and heterozygosity were high for all populations except the island population of Uganda and A. m. bervoetsi. High levels of genetic differentiation were recorded between A. m. bervoetsi and each A. m. moucheti sample as well as between the island population of A. m. moucheti and mainland populations. Significant isolation by distance was evidenced between mainland populations. Conclusion High levels of genetic differentiation supports complete speciation of A. m. bervoetsi which should henceforth be recognized as a full species and named A. bervoetsi. Isolation by distance is the main force driving differentiation between mainland populations of A. m. moucheti. Genetically and geographically isolated populations exist on Lake Victoria islands, which might serve as relevant field sites for evaluation of innovative vector control strategies.
Collapse
Affiliation(s)
- Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la Lutte contre les Endémies en Afrique Centrale (OCEAC), P,O, Box 288, Yaoundé, Cameroon.
| | | | | | | | | | | | | |
Collapse
|
16
|
A test of the chromosomal theory of ecotypic speciation in Anopheles gambiae. Proc Natl Acad Sci U S A 2008; 105:2940-5. [PMID: 18287019 DOI: 10.1073/pnas.0709806105] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The role of chromosomal inversions in speciation has long been of interest to evolutionists. Recent quantitative modeling has stimulated reconsideration of previous conceptual models for chromosomal speciation. Anopheles gambiae, the most important vector of human malaria, carries abundant chromosomal inversion polymorphism nonrandomly associated with ecotypes that mate assortatively. Here, we consider the potential role of paracentric inversions in promoting speciation in A. gambiae via "ecotypification," a term that refers to differentiation arising from local adaptation. In particular, we focus on the Bamako form, an ecotype characterized by low inversion polymorphism and fixation of an inversion, 2Rj, that is very rare or absent in all other forms of A. gambiae. The Bamako form has a restricted distribution by the upper Niger River and its tributaries that is associated with a distinctive type of larval habitat, laterite rock pools, hypothesized to be its optimal breeding site. We first present computer simulations to investigate whether the population dynamics of A. gambiae are consistent with chromosomal speciation by ecotypification. The models are parameterized using field observations on the various forms of A. gambiae that exist in Mali, West Africa. We then report on the distribution of larvae of this species collected from rock pools and more characteristic breeding sites nearby. Both the simulations and field observations support the thesis that speciation by ecotypification is occurring, or has occurred, prompting consideration of Bamako as an independent species.
Collapse
|
17
|
Moreno M, Salgueiro P, Vicente JL, Cano J, Berzosa PJ, de Lucio A, Simard F, Caccone A, Do Rosario VE, Pinto J, Benito A. Genetic population structure of Anopheles gambiae in Equatorial Guinea. Malar J 2007; 6:137. [PMID: 17937805 PMCID: PMC2100067 DOI: 10.1186/1475-2875-6-137] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 10/15/2007] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Patterns of genetic structure among mosquito vector populations in islands have received particular attention as these are considered potentially suitable sites for experimental trials on transgenic-based malaria control strategies. In this study, levels of genetic differentiation have been estimated between populations of Anopheles gambiae s.s. from the islands of Bioko and Annobón, and from continental Equatorial Guinea (EG) and Gabon. METHODS Genotyping of 11 microsatellite loci located in chromosome 3 was performed in three island samples (two in Bioko and one in Annobón) and three mainland samples (two in EG and one in Gabon). Four samples belonged to the M molecular form and two to the S-form. Microsatellite data was used to estimate genetic diversity parameters, perform demographic equilibrium tests and analyse population differentiation. RESULTS High levels of genetic differentiation were found between the more geographically remote island of Annobón and the continent, contrasting with the shallow differentiation between Bioko island, closest to mainland, and continental localities. In Bioko, differentiation between M and S forms was higher than that observed between island and mainland samples of the same molecular form. CONCLUSION The observed patterns of population structure seem to be governed by the presence of both physical (the ocean) and biological (the M-S form discontinuity) barriers to gene flow. The significant degree of genetic isolation between M and S forms detected by microsatellite loci located outside the "genomic islands" of speciation identified in A. gambiae s.s. further supports the hypothesis of on-going incipient speciation within this species. The implications of these findings regarding vector control strategies are discussed.
Collapse
Affiliation(s)
- Marta Moreno
- Centro Nacional de Medicina Tropical. Instituto de Salud Carlos III. C/Sinesio Delgado 4, 28029 Madrid, Spain
| | - Patricia Salgueiro
- Centro de Malária e outras Doenças Tropicais, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - José Luis Vicente
- Centro de Malária e outras Doenças Tropicais, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Jorge Cano
- Centro Nacional de Medicina Tropical. Instituto de Salud Carlos III. C/Sinesio Delgado 4, 28029 Madrid, Spain
- Centro de Referencia para el Control de Endemias. Centro Nacional de Medicina Tropical, Instituto de Salud Carlos III, Bata, Equatorial Guinea
| | - Pedro J Berzosa
- Centro Nacional de Medicina Tropical. Instituto de Salud Carlos III. C/Sinesio Delgado 4, 28029 Madrid, Spain
| | - Aida de Lucio
- Centro Nacional de Medicina Tropical. Instituto de Salud Carlos III. C/Sinesio Delgado 4, 28029 Madrid, Spain
| | - Frederic Simard
- Institut de Recherche pour le Développement, Unité 016, Montpellier, France
- Organisation de Coordination pour la Lutte contre les Endémies en Afrique Centrale, Yaoundé, Cameroun
| | - Adalgisa Caccone
- Yale Institute for Biospheric Studies and Department of Ecology and Evolutionary Biology, Yale University, New Haven, USA
| | - Virgilio E Do Rosario
- Centro de Malária e outras Doenças Tropicais, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - João Pinto
- Centro de Malária e outras Doenças Tropicais, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Agustín Benito
- Centro Nacional de Medicina Tropical. Instituto de Salud Carlos III. C/Sinesio Delgado 4, 28029 Madrid, Spain
| |
Collapse
|
18
|
Antonio-Nkondjio C, Ndo C, Awono-Ambene P, Ngassam P, Fontenille D, Simard F. Population genetic structure of the malaria vector Anopheles moucheti in south Cameroon forest region. Acta Trop 2007; 101:61-8. [PMID: 17227668 DOI: 10.1016/j.actatropica.2006.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 12/03/2006] [Accepted: 12/06/2006] [Indexed: 11/24/2022]
Abstract
We used recently developed microsatellite DNA markers to explore the population genetic structure of the malaria vector, Anopheles moucheti. Polymorphism at 10 loci was examined to assess level of genetic differentiation between four A. moucheti populations from South Cameroon situated 65-400 km apart. All microsatellite loci were highly polymorphic with a number of distinct alleles per locus ranging from 9 to 17. Fst estimates ranging from 0.0094 to 0.0275 (P < 0.001) were recorded. These results suggest a very low level of genetic differentiation between A. moucheti populations. The recently available microsatellite loci revealed useful markers to assess genetic differentiation between geographical populations of A. moucheti in Cameroon.
Collapse
Affiliation(s)
- Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 15665, Yaoundé, Cameroon.
| | | | | | | | | | | |
Collapse
|