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Background Whole genome re-sequencing provides powerful data for population genomic studies, allowing robust inferences of population structure, gene flow and evolutionary history. For the major malaria vector in Africa, Anopheles gambiae, other genetic aspects such as selection and adaptation are also important. In the present study, we explore population genetic variation from genome-wide sequencing of 765 An. gambiae and An. coluzzii specimens collected from across Africa. We used t-SNE, a recently popularized dimensionality reduction method, to create a 2D-map of An. gambiae and An. coluzzii genes that reflect their population structure similarities. Results The map allows intuitive navigation among genes distributed throughout the so-called “mainland” and numerous surrounding “island-like” gene clusters. These gene clusters of various sizes correspond predominantly to low recombination genomic regions such as inversions and centromeres, and also to recent selective sweeps. Because this mosquito species complex has been studied extensively, we were able to support our interpretations with previously published findings. Several novel observations and hypotheses are also made, including selective sweeps and a multi-locus selection event in Guinea-Bissau, a known intense hybridization zone between An. gambiae and An. coluzzii. Conclusions Our results present a rich dataset that could be utilized in functional investigations aiming to shed light onto An. gambiae s.l genome evolution and eventual speciation. In addition, the methodology presented here can be used to further characterize other species not so well studied as An. gambiae, shortening the time required to progress from field sampling to the identification of genes and genomic regions under unique evolutionary processes.

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.

Anopheles coluzzii is a major malaria vector throughout its distribution in west-central Africa. Here we present a whole-genome study of 142 specimens from nine countries in continental Africa and three islands in the Gulf of Guinea. This sample set covers a large part of this species’ geographic range. Our population genomic analyses included a description of the structure of mainland populations, island populations, and connectivity between them. Three genetic clusters are identified among mainland populations and genetic distances (FST) fits an isolation-by-distance model. Genomic analyses are applied to estimate the demographic history and ancestry for each island. Taken together with the unique biogeography and history of human occupation for each island, they present a coherent explanation underlying levels of genetic isolation between mainland and island populations. We discuss the relationship of our findings to the suitability of São Tomé and Príncipe islands as candidate sites for potential field trials of genetic-based malaria control strategies., Campos, Lanzaro and colleagues use whole-genome sequencing and population genomic analyses to infer connectivity between mainland and island mosquito populations in West Africa. The unique biogeographic history for each island population is reported, and the findings highlight potential candidate sites for genetic-based malaria control strategies.

We report the first complete mitogenome (Mt) sequence of Anopheles coustani, an understudied malaria vector in Africa. The sequence was extracted from one individual mosquito from São Tomé island. The length of the A. coustani Mt genome was 15,408 bp with 79.3% AT content. Phylogenetic analysis revealed that A. coustani is most closely related to A. sinensis (93.5% of identity); and 90.1% identical to A. gambiae complex members. publishersversion published

Anopheles coluzzii is a major malaria vector throughout its distribution in west-central Africa. Here we present a whole-genome resequencing study of 77 specimens from eight localities, that covers a large part of this species’ range, including three islands in the Gulf of Guinea: Bioko, Sao Tome and Principe. Population genomic analyses encompassed structure of mainland populations, of island populations and connectivity between island and mainland populations. Three genetic clusters were found among mainland populations and genetic distances among all populations fit an isolation-by-distance model. Genomic analyses were applied to estimating the demographic history and ancestry (cross-coalescence) for each island. Taken together with the unique biogeography and history of human occupation for each island they present a coherent explanation underlying contemporary levels of genetic isolation between mainland and island populations and among island populations. We discuss the relation of our findings to the suitability of Sao Tome and Principe islands as candidate sites for potential field trials of genetic-based malaria control strategies.

Made available in DSpace on 2019-10-06T17:09:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-05-17 Background: In the Amazon Basin, Nyssorhynchus (Anopheles) darlingi is the most aggressive and effective malaria vector. In endemic areas, behavioral aspects of anopheline vectors such as host preference, biting time and resting location post blood meal have a key impact on malaria transmission dynamics and vector control interventions. Nyssorhynchus darlingi presents a range of feeding and resting behaviors throughout its broad distribution. Methods: To investigate the genetic diversity related to biting behavior, we collected host-seeking Ny. darlingi in two settlement types in Acre, Brazil: Granada (~ 20-year-old, more established, better access by road, few malaria cases) and Remansinho (~ 8-year-old, active logging, poor road access, high numbers malaria cases). Mosquitoes were classified by the location of collection (indoors or outdoors) and time (dusk or dawn). Results: Genome-wide SNPs, used to assess the degree of genetic divergence and population structure, identified non-random distributions of individuals in the PCA for both location and time analyses. Although genetic diversity related to behavior was confirmed by non-model-based analyses and F ST values, model-based STRUCTURE detected considerable admixture of these populations. Conclusions: To our knowledge, this is the first study to detect genetic markers associated with biting behavior in Ny. darlingi. Additional ecological and genomic studies may help to understand the genetic basis of mosquito behavior and address appropriate surveillance and vector control. Biotechnology Institute (IBTEC) Biosciences Institute at Botucatu (IBB) Sao Paulo State University (UNESP) Department of Biomedical Sciences School of Public Health University at Albany (State University of New York) Wadsworth Center New York State Department of Health Division of Infectious Diseases Department of Medicine University of California San Diego Laboratorio de Investigación y Desarrollo Departamento de Ciencias Celulares y Moleculares Instituto de Medicina Tropical Alexander von Humboldt Universidad Peruana Cayetano Heredia Biology Department St. Mary's College of Maryland Biotechnology Institute (IBTEC) Biosciences Institute at Botucatu (IBB) Sao Paulo State University (UNESP)

In the Amazon Basin, Anopheles (Nyssorhynchus) darlingi is the most aggressive and effective malaria vector. In endemic areas, behavioral aspects of anopheline species such as host preference, biting time and resting location after a blood meal have a key impact on malaria transmission dynamics and transmission control strategies. An. darlingi present a variety in behavior throughout its broad distribution including blood feeding related. To investigate the genetic basis of its biting behaviors, host-seeking An. darlingi were collected in two settlements (Granada and Remansinho) in Acre, Brazil. Mosquitoes were classified by captured location (indoors or outdoors) and time (dusk or dawn). Genome-wide SNPs were used to assess the degree of genetic diversity and structure in these groups. There was evidence of genetic component of biting behavior regarding both location and time in this species. This study supports that An. darlingi blood-feeding behavior has a genetic component. Additional ecological and genomic studies may help to understand the genetic basis of mosquito behavior and address appropriate surveillance and vector control.Author SummaryMalaria is a disease caused by parasite of the genus Plasmodium and is transmitted by mosquitoes of the genus Anopheles. In the Amazon Basin, the main malaria vector is Anopheles darlingi, which is present in high densities in this region. Egg development requires that females of this mosquito seek hosts for blood meals. Anopheles females blood feeding may occur indoor or outdoor the houses and typically from the sunset to dawn. Anopheles darlingi in particular present great variability regarding its behaviour, presenting variety of peak biting times and patterns. This work shows that there is a genetic component that partially explains these two behaviors: location of the blood meal (inside or outside the houses) and time of feeding. Single nucleotide polymorphisms (SNPs) scattered throughout the genome of Anopheles darlingi showed genetic diversity and structure in these groups. A comprehensive understanding of the genetic basis for mosquito behaviour may support innovative vector surveillance and control strategies.

Made available in DSpace on 2018-12-11T17:31:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-02-13 Background: In recent decades, throughout the Amazon Basin, landscape modification contributing to profound ecological change has proceeded at an unprecedented rate. Deforestation that accompanies human activities can significantly change aspects of anopheline biology, though this may be site-specific. Such local changes in anopheline biology could have a great impact on malaria transmission. The aim of this study was to investigate population genetics of the main malaria vector in Brazil, Anopheles darlingi, from a microgeographical perspective. Methods: Microsatellites and ddRADseq-derived single nucleotide polymorphisms (SNPs) were used to assess levels of population genetic structuring among mosquito populations from two ecologically distinctive agricultural settlements (~60 km apart) and a population from a distant (~700 km) urban setting in the western Amazon region of Brazil. Results: Significant microgeographical population differentiation was observed among Anopheles darlingi populations via both model- and non-model-based analysis only with the SNP dataset. Microsatellites detected moderate differentiation at the greatest distances, but were unable to differentiate populations from the two agricultural settlements. Both markers showed low polymorphism levels in the most human impacted sites. Conclusions: At a microgeographical scale, signatures of genetic heterogeneity and population divergence were evident in Anopheles darlingi, possibly related to local environmental anthropic modification. This divergence was observed only when using high coverage SNP markers. Biotechnology Institute (IBTEC) and Biosciences Institute at Botucatu (IBB) Sao Paulo State University (UNESP) Department of Biomedical Sciences School of Public Health University at Albany State University of New York New York State Department of Health Wadsworth Center Division of Infectious Diseases Department of Medicine University of California San Diego Instituto de Medicina Tropical Alexander von Humboldt, Departamento de Ciencias Celulares y Moleculares Laboratorio de Investigación y Desarrollo Universidad Peruana Cayetano Heredia Biology Department St. Mary's College of Maryland Biotechnology Institute (IBTEC) and Biosciences Institute at Botucatu (IBB) Sao Paulo State University (UNESP)

Made available in DSpace on 2014-09-30T18:18:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2013Bitstream added on 2014-10-01T14:04:14Z : No. of bitstreams: 1 S0074-02762013000900003.pdf: 529161 bytes, checksum: 81385c72bbd25c5d11a271d286f7317a (MD5) The increasing population of Aedes aegypti mosquitoes on Madeira Island (Portugal) resulted in the first autochthonous dengue outbreak, which occurred in October 2012. Our study establishes the first genetic evaluation based on the mitochondrial DNA (mtDNA) genes [cytochrome oxidase subunit I (COI) and NADH dehydrogenase subunit 4 (ND4)] and knockdown resistance ( kdr ) mutations exploring the colonisation history and the genetic diversity of this insular vector population. We included mosquito populations from Brazil and Venezuela in the analysis as putative geographic sources. The Ae. aegyptipopulation from Madeira showed extremely low mtDNA genetic variability, with a single haplotype for COI and ND4. We also detected the presence of two important kdr mutations and the quasi-fixation of one of these mutations (F1534C). These results are consistent with a unique recent founder event that occurred on the island of Ae. aegyptimosquitoes that carry kdr mutations associated with insecticide resistance. Finally, we also report the presence of the F1534C kdr mutation in the Brazil and Venezuela populations. To our knowledge, this is the first time this mutation has been found in South American Ae. aegypti mosquitoes. Given the present risk of Ae. aegypti re-invading continental Europe from Madeira and the recent dengue outbreaks on the island, this information is important to plan surveillance and control measures. Unidade de Ensino e Investigacao-Parasitologia Medica Centro de Malaria e outras Doencas Tropicais Universidade Nova de Lisboa Instituto de Higiene e Medicina Tropical Unidade de Parasitologia e Microbiologia Medicas Instituto de Administracao da Saude e Assuntos Sociais Unidade de Engenharia Sanitaria Departamento de Promocao e Protecao da Saude Universidade Estadual Paulista Instituto de Biociencias Departamento de Parasitologia Universidad Central de Venezuela Instituto de Medicina Tropical Seccion Entomologia Medica Universidade Estadual Paulista Instituto de Biociencias Departamento de Parasitologia