32 research outputs found

    De Novo Transcriptome Sequencing in Anopheles funestus Using Illumina RNA-Seq Technology

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    BACKGROUND: Anopheles funestus is one of the primary vectors of human malaria, which causes a million deaths each year in sub-Saharan Africa. Few scientific resources are available to facilitate studies of this mosquito species and relatively little is known about its basic biology and evolution, making development and implementation of novel disease control efforts more difficult. The An. funestus genome has not been sequenced, so in order to facilitate genome-scale experimental biology, we have sequenced the adult female transcriptome of An. funestus from a newly founded colony in Burkina Faso, West Africa, using the Illumina GAIIx next generation sequencing platform. METHODOLOGY/PRINCIPAL FINDINGS: We assembled short Illumina reads de novo using a novel approach involving iterative de novo assemblies and "target-based" contig clustering. We then selected a conservative set of 15,527 contigs through comparisons to four Dipteran transcriptomes as well as multiple functional and conserved protein domain databases. Comparison to the Anopheles gambiae immune system identified 339 contigs as putative immune genes, thus identifying a large portion of the immune system that can form the basis for subsequent studies of this important malaria vector. We identified 5,434 1:1 orthologues between An. funestus and An. gambiae and found that among these 1:1 orthologues, the protein sequence of those with putative immune function were significantly more diverged than the transcriptome as a whole. Short read alignments to the contig set revealed almost 367,000 genetic polymorphisms segregating in the An. funestus colony and demonstrated the utility of the assembled transcriptome for use in RNA-seq based measurements of gene expression. CONCLUSIONS/SIGNIFICANCE: We developed a pipeline that makes de novo transcriptome sequencing possible in virtually any organism at a very reasonable cost ($6,300 in sequencing costs in our case). We anticipate that our approach could be used to develop genomic resources in a diversity of systems for which full genome sequence is currently unavailable. Our An. funestus contig set and analytical results provide a valuable resource for future studies in this non-model, but epidemiologically critical, vector insect

    Polymorphisms in Anopheles gambiae Immune Genes Associated with Natural Resistance to Plasmodium falciparum

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    Many genes involved in the immune response of Anopheles gambiae, the main malaria vector in Africa, have been identified, but whether naturally occurring polymorphisms in these genes underlie variation in resistance to the human malaria parasite, Plasmodium falciparum, is currently unknown. Here we carried out a candidate gene association study to identify single nucleotide polymorphisms (SNPs) associated with natural resistance to P. falciparum. A. gambiae M form mosquitoes from Cameroon were experimentally challenged with three local wild P. falciparum isolates. Statistical associations were assessed between 157 SNPs selected from a set of 67 A. gambiae immune-related genes and the level of infection. Isolate-specific associations were accounted for by including the effect of the isolate in the analysis. Five SNPs were significantly associated to the infection phenotype, located within or upstream of AgMDL1, CEC1, Sp PPO activate, Sp SNAKElike, and TOLL6. Low overall and local linkage disequilibrium indicated high specificity in the loci found. Association between infection phenotype and two SNPs was isolate-specific, providing the first evidence of vector genotype by parasite isolate interactions at the molecular level. Four SNPs were associated to either oocyst presence or load, indicating that the genetic basis of infection prevalence and intensity may differ. The validity of the approach was verified by confirming the functional role of Sp SNAKElike in gene silencing assays. These results strongly support the role of genetic variation within or near these five A. gambiae immune genes, in concert with other genes, in natural resistance to P. falciparum. They emphasize the need to distinguish between infection prevalence and intensity and to account for the genetic specificity of vector-parasite interactions in dissecting the genetic basis of Anopheles resistance to human malaria

    Site suitability analysis of indigenous rainwater harvesting systems in arid and data-poor environments: a case study of Sana’a Basin, Yemen

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    Indigenous rainwater harvesting (RWH) is a promising tool for increasing water availability and conserving groundwater in arid environments. This study aimed to develop a multicriteria analysis (MCA) framework to identify and rank suitable sites for different indigenous RWH systems in data-poor areas taking Sana’a Basin, Yemen, as a case study. Unlike previous research, this study focused only on indigenous RWH systems and, for the first time, considered the site suitability analysis of spate irrigation systems. Five biophysical and six socioeconomic criteria were used to select, prioritize, and map suitable zones for indigenous RWH systems. This study, the first to be conducted in Yemen, found that more than 30% of the case area has a high or very high level of suitability for each of the studied RWH systems. Only 11% to 17% of the area is not suitable for RWH due to socioeconomic activities. Twenty-four percent of the area was considered moderately suitable, and 28% had a low level of suitability for RWH. These results are promising, and the preliminary identification process of suitable areas for indigenous RWH systems is a useful guide for future water resource and land management programs

    Site suitability analysis of indigenous rainwater harvesting systems in arid and data-poor environments: a case study of Sana’a Basin, Yemen

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    Abstract: Indigenous rainwater harvesting (RWH) is a promising tool for increasing water availability and conserving groundwater in arid environments. This study aimed to develop a multicriteria analysis (MCA) framework to identify and rank suitable sites for different indigenous RWH systems in data-poor areas taking Sana’a Basin, Yemen, as a case study. Unlike previous research, this study focused only on indigenous RWH systems and, for the first time, considered the site suitability analysis of spate irrigation systems. Five biophysical and six socioeconomic criteria were used to select, prioritize, and map suitable zones for indigenous RWH systems. This study, the first to be conducted in Yemen, found that more than 30% of the case area has a high or very high level of suitability for each of the studied RWH systems. Only 11% to 17% of the area is not suitable for RWH due to socioeconomic activities. Twenty-four percent of the area was considered moderately suitable, and 28% had a low level of suitability for RWH. These results are promising, and the preliminary identification process of suitable areas for indigenous RWH systems is a useful guide for future water resource and land management programs. Graphical abstract: [Figure not available: see fulltext.]

    Macrodactyly with skin hypertrophy: a minimal form of the Proteus syndrome Macrodactilia com hipertrofia da pele: uma forma mínima da síndrome de Proteu

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    The Proteus syndrome was described 1983 . It has asymmetric gigantism of the limbs, verrucous epidermal naevi, cerebriform enlargement of the plantar region, vascular malformations and neoplasms, as lipomas. It received this denomination after Proteus from the Greek mythology, who had the ability to change his form . A 15 year-old boy, reported a congenital hypertrophy with syndactily of the second and third right fingers . The second case is a 35 year-old man, who reported that since birth the second right toe was bigger than the other toes, skin hypertrophy was also observed. These cases document a localized form if the Proteus syndrome, which may widen the spectrum of its variability<br>A síndorme de Proteus foi descrita por Wiedemann em 1983. Ela é caracterizada por gigantismo assimétrico dos membros, nevos epidérmicos verrucosos, hipertrofia cerebriforme da região plantar, neoformações vasculares e neoplasias, como lipomas. Essa polimórfica enfermidade recebeu essa denominação segundo a figura da mitologia grega, a qual tinha como característica a habilidade de mudar de forma, para evitar sua captura. Examinou-se um menino de 15 anos, o qual referiu hipertrofia e sindactilia do segundo e terceiro quirodáctilos direitos e um homem de 35 anos, que referiu hipertrofia congênita do segundo pododáctilo direito. Havia hipertrofia da pele em ambos os casos. Esses dois pacientes documentam formas localizadas dessa síndrome, ampliando seu espectro clínic
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