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1.
Proc Natl Acad Sci U S A ; 119(30): e2122165119, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35867831

RESUMO

Successful infectious disease interventions can result in large reductions in parasite prevalence. Such demographic change has fitness implications for individual parasites and may shift the parasite's optimal life history strategy. Here, we explore whether declining infection rates can alter Plasmodium falciparum's investment in sexual versus asexual growth. Using a multiscale mathematical model, we demonstrate how the proportion of polyclonal infections, which decreases as parasite prevalence declines, affects the optimal sexual development strategy: Within-host competition in multiclone infections favors a greater investment in asexual growth whereas single-clone infections benefit from higher conversion to sexual forms. At the same time, drug treatment also imposes selection pressure on sexual development by shortening infection length and reducing within-host competition. We assess these models using 148 P. falciparum parasite genomes sampled in French Guiana over an 18-y period of intensive intervention (1998 to 2015). During this time frame, multiple public health measures, including the introduction of new drugs and expanded rapid diagnostic testing, were implemented, reducing P. falciparum malaria cases by an order of magnitude. Consistent with this prevalence decline, we see an increase in the relatedness among parasites, but no single clonal background grew to dominate the population. Analyzing individual allele frequency trajectories, we identify genes that likely experienced selective sweeps. Supporting our model predictions, genes showing the strongest signatures of selection include transcription factors involved in the development of P. falciparum's sexual gametocyte form. These results highlight how public health interventions impose wide-ranging selection pressures that affect basic parasite life history traits.


Assuntos
Malária Falciparum , Plasmodium falciparum , Animais , Antimaláricos/farmacologia , Frequência do Gene , Humanos , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Modelos Biológicos , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Plasmodium falciparum/crescimento & desenvolvimento , Prevalência
2.
Nat Commun ; 13(1): 2830, 2022 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-35595835

RESUMO

The lack of validated, distributed comprehensive genomic profiling assays for patients with cancer inhibits access to precision oncology treatment. To address this, we describe elio tissue complete, which has been FDA-cleared for examination of 505 cancer-related genes. Independent analyses of clinically and biologically relevant sequence changes across 170 clinical tumor samples using MSK-IMPACT, FoundationOne, and PCR-based methods reveals a positive percent agreement of >97%. We observe high concordance with whole-exome sequencing for evaluation of tumor mutational burden for 307 solid tumors (Pearson r = 0.95) and comparison of the elio tissue complete microsatellite instability detection approach with an independent PCR assay for 223 samples displays a positive percent agreement of 99%. Finally, evaluation of amplifications and translocations against DNA- and RNA-based approaches exhibits >98% negative percent agreement and positive percent agreement of 86% and 82%, respectively. These methods provide an approach for pan-solid tumor comprehensive genomic profiling with high analytical performance.


Assuntos
Neoplasias , Biomarcadores Tumorais/genética , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Mutação , Neoplasias/patologia , Medicina de Precisão
3.
Nat Med ; 25(12): 1858-1864, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31768064

RESUMO

Multidrug resistant organisms are a serious threat to human health1,2. Fast, accurate antibiotic susceptibility testing (AST) is a critical need in addressing escalating antibiotic resistance, since delays in identifying multidrug resistant organisms increase mortality3,4 and use of broad-spectrum antibiotics, further selecting for resistant organisms. Yet current growth-based AST assays, such as broth microdilution5, require several days before informing key clinical decisions. Rapid AST would transform the care of patients with infection while ensuring that our antibiotic arsenal is deployed as efficiently as possible. Growth-based assays are fundamentally constrained in speed by doubling time of the pathogen, and genotypic assays are limited by the ever-growing diversity and complexity of bacterial antibiotic resistance mechanisms. Here we describe a rapid assay for combined genotypic and phenotypic AST through RNA detection, GoPhAST-R, that classifies strains with 94-99% accuracy by coupling machine learning analysis of early antibiotic-induced transcriptional changes with simultaneous detection of key genetic resistance determinants to increase accuracy of resistance detection, facilitate molecular epidemiology and enable early detection of emerging resistance mechanisms. This two-pronged approach provides phenotypic AST 24-36 h faster than standard workflows, with <4 h assay time on a pilot instrument for hybridization-based multiplexed RNA detection implemented directly from positive blood cultures.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Testes de Sensibilidade Microbiana , RNA Bacteriano/isolamento & purificação , Antibacterianos/efeitos adversos , Genótipo , Humanos , Aprendizado de Máquina , Fenótipo , RNA Bacteriano/efeitos dos fármacos
4.
PLoS One ; 14(10): e0223364, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31577829

RESUMO

BACKGROUND: Prophages play a significant role in prokaryotic evolution, often altering the function of the cell that they infect via transfer of new genes e.g., virulence or antibiotic resistance factors, inactivation of existing genes or by modifying gene expression. Recently, phage therapy has gathered renewed interest as a promising alternative to control bacterial infections. Cataloging the repertoire of prophages in large collections of species' genomes is an important initial step in understanding their evolution and potential therapeutic utility. However, current widely-used tools for identifying prophages within bacterial genome sequences are mainly web-based, can have long response times, and do not scale to keep pace with the many thousands of genomes currently being sequenced routinely. METHODOLOGY: In this work, we present ProphET, an easy to install prophage predictor to be used in Linux operation system, without the constraints associated with a web-based tool. ProphET predictions rely on similarity searches against a database of prophage genes, taking as input a bacterial genome sequence in FASTA format and its corresponding gene annotation in GFF. ProphET identifies prophages in three steps: similarity search, calculation of the density of prophage genes, and edge refinement. ProphET performance was evaluated and compared with other phage predictors based on a set of 54 bacterial genomes containing 267 manually annotated prophages. FINDINGS AND CONCLUSIONS: ProphET identifies prophages in bacterial genomes with high precision and offers a fast, highly scalable alternative to widely-used web-based applications for prophage detection.


Assuntos
Biologia Computacional/métodos , Genômica/métodos , Prófagos/genética , Software , Bases de Dados de Ácidos Nucleicos , Genoma Viral , Anotação de Sequência Molecular , Sensibilidade e Especificidade , Navegador
5.
Mycopathologia ; 183(4): 645-658, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29500637

RESUMO

With the increasing numbers of immunocompromised hosts, Aspergillus fumigatus emerges as a lethal opportunistic fungal pathogen. Understanding innate and acquired immunity responses of the host is important for a better therapeutic strategy to deal with aspergillosis patients. To determine the transcriptome in the kidneys in aspergillosis, we employed RNA-Seq to obtain single 76-base reads of whole-genome transcripts of murine kidneys on a temporal basis (days 0; uninfected, 1, 2, 3 and 8) during invasive aspergillosis. A total of 6284 transcripts were downregulated, and 5602 were upregulated compared to baseline expression. Gene ontology enrichment analysis identified genes involved in innate and adaptive immune response, as well as iron binding and homeostasis, among others. Our results showed activation of pathogen recognition receptors, e.g., ß-defensins, C-type lectins (e.g., dectin-1), Toll-like receptors (TLR-2, TLR-3, TLR-8, TLR-9 and TLR-13), as well as Ptx-3 and C-reactive protein among the soluble receptors. Upregulated transcripts encoding various differentiating cytokines and effector proinflammatory cytokines, as well as those encoding for chemokines and chemokine receptors, revealed Th-1 and Th-17-type immune responses. These studies form a basic dataset for experimental prioritization, including other target organs, to determine the global response of the host against Aspergillus infection.


Assuntos
Aspergilose/patologia , Aspergillus fumigatus/imunologia , Perfilação da Expressão Gênica , Rim/patologia , Células Th1/imunologia , Células Th17/imunologia , Animais , Modelos Animais de Doenças , Feminino , Fatores Imunológicos/biossíntese , Fatores Imunológicos/genética , Camundongos , Análise de Sequência de RNA , Fatores de Tempo
6.
PLoS Genet ; 13(10): e1007065, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29077712

RESUMO

With the rapidly increasing abundance and accessibility of genomic data, there is a growing interest in using population genetic approaches to characterize fine-scale dispersal of organisms, providing insight into biological processes across a broad range of fields including ecology, evolution and epidemiology. For sexually recombining haploid organisms such as the human malaria parasite P. falciparum, however, there have been no systematic assessments of the type of data and methods required to resolve fine scale connectivity. This analytical gap hinders the use of genomics for understanding local transmission patterns, a crucial goal for policy makers charged with eliminating this important human pathogen. Here we use data collected from four clinics with a catchment area spanning approximately 120 km of the Thai-Myanmar border to compare the ability of divergence (FST) and relatedness based on identity by descent (IBD) to resolve spatial connectivity between malaria parasites collected from proximal clinics. We found no relationship between inter-clinic distance and FST, likely due to sampling of highly related parasites within clinics, but a significant decline in IBD-based relatedness with increasing inter-clinic distance. This association was contingent upon the data set type and size. We estimated that approximately 147 single-infection whole genome sequenced parasite samples or 222 single-infection parasite samples genotyped at 93 single nucleotide polymorphisms (SNPs) were sufficient to recover a robust spatial trend estimate at this scale. In summary, surveillance efforts cannot rely on classical measures of genetic divergence to measure P. falciparum transmission on a local scale. Given adequate sampling, IBD-based relatedness provides a useful alternative, and robust trends can be obtained from parasite samples genotyped at approximately 100 SNPs.


Assuntos
Malária Falciparum/parasitologia , Plasmodium falciparum/genética , DNA de Protozoário/genética , Genoma de Protozoário/genética , Haplótipos/genética , Humanos , Polimorfismo de Nucleotídeo Único/genética , Tailândia
7.
Genome Biol ; 18(1): 78, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28454557

RESUMO

BACKGROUND: Artemisinin-based combination therapies are the first line of treatment for Plasmodium falciparum infections worldwide, but artemisinin resistance has risen rapidly in Southeast Asia over the past decade. Mutations in the kelch13 gene have been implicated in this resistance. We used longitudinal genomic surveillance to detect signals in kelch13 and other loci that contribute to artemisinin or partner drug resistance. We retrospectively sequenced the genomes of 194 P. falciparum isolates from five sites in Northwest Thailand, over the period of a rapid increase in the emergence of artemisinin resistance (2001-2014). RESULTS: We evaluate statistical metrics for temporal change in the frequency of individual SNPs, assuming that SNPs associated with resistance increase in frequency over this period. After Kelch13-C580Y, the strongest temporal change is seen at a SNP in phosphatidylinositol 4-kinase, which is involved in a pathway recently implicated in artemisinin resistance. Furthermore, other loci exhibit strong temporal signatures which warrant further investigation for involvement in artemisinin resistance evolution. Through genome-wide association analysis we identify a variant in a kelch domain-containing gene on chromosome 10 that may epistatically modulate artemisinin resistance. CONCLUSIONS: This analysis demonstrates the potential of a longitudinal genomic surveillance approach to detect resistance-associated gene loci to improve our mechanistic understanding of how resistance develops. Evidence for additional genomic regions outside of the kelch13 locus associated with artemisinin-resistant parasites may yield new molecular markers for resistance surveillance, which may be useful in efforts to reduce the emergence or spread of artemisinin resistance in African parasite populations.


Assuntos
Antimaláricos/farmacologia , Artemisininas/farmacologia , Resistência a Medicamentos/genética , Genoma de Protozoário , Plasmodium falciparum/genética , Repetição Kelch , Plasmodium falciparum/efeitos dos fármacos , Polimorfismo de Nucleotídeo Único , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo
8.
Genome Biol ; 18(1): 28, 2017 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-28196534

RESUMO

BACKGROUND: The fungal genus Aspergillus is of critical importance to humankind. Species include those with industrial applications, important pathogens of humans, animals and crops, a source of potent carcinogenic contaminants of food, and an important genetic model. The genome sequences of eight aspergilli have already been explored to investigate aspects of fungal biology, raising questions about evolution and specialization within this genus. RESULTS: We have generated genome sequences for ten novel, highly diverse Aspergillus species and compared these in detail to sister and more distant genera. Comparative studies of key aspects of fungal biology, including primary and secondary metabolism, stress response, biomass degradation, and signal transduction, revealed both conservation and diversity among the species. Observed genomic differences were validated with experimental studies. This revealed several highlights, such as the potential for sex in asexual species, organic acid production genes being a key feature of black aspergilli, alternative approaches for degrading plant biomass, and indications for the genetic basis of stress response. A genome-wide phylogenetic analysis demonstrated in detail the relationship of the newly genome sequenced species with other aspergilli. CONCLUSIONS: Many aspects of biological differences between fungal species cannot be explained by current knowledge obtained from genome sequences. The comparative genomics and experimental study, presented here, allows for the first time a genus-wide view of the biological diversity of the aspergilli and in many, but not all, cases linked genome differences to phenotype. Insights gained could be exploited for biotechnological and medical applications of fungi.


Assuntos
Adaptação Biológica , Aspergillus/classificação , Aspergillus/genética , Biodiversidade , Genoma Fúngico , Genômica , Aspergillus/metabolismo , Biomassa , Carbono/metabolismo , Biologia Computacional/métodos , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Metilação de DNA , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Redes Reguladoras de Genes , Genômica/métodos , Humanos , Redes e Vias Metabólicas , Anotação de Sequência Molecular , Família Multigênica , Oxirredutases/metabolismo , Filogenia , Plantas/metabolismo , Plantas/microbiologia , Metabolismo Secundário/genética , Transdução de Sinais , Estresse Fisiológico/genética
9.
Proc Natl Acad Sci U S A ; 114(5): 1135-1140, 2017 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-28096418

RESUMO

Carbapenem-resistant Enterobacteriaceae (CRE) are among the most severe threats to the antibiotic era. Multiple different species can exhibit resistance due to many different mechanisms, and many different mobile elements are capable of transferring resistance between lineages. We prospectively sampled CRE from hospitalized patients from three Boston-area hospitals, together with a collection of CRE from a single California hospital, to define the frequency and characteristics of outbreaks and determine whether there is evidence for transfer of strains within and between hospitals and the frequency with which resistance is transferred between lineages or species. We found eight species exhibiting resistance, with the majority of our sample being the sequence type 258 (ST258) lineage of Klebsiella pneumoniae There was very little evidence of extensive hospital outbreaks, but a great deal of variation in resistance mechanisms and the genomic backgrounds carrying these mechanisms. Local transmission was evident in clear phylogeographic structure between the samples from the two coasts. The most common resistance mechanisms were KPC (K. pneumoniae carbapenemases) beta-lactamases encoded by blaKPC2, blaKPC3, and blaKPC4, which were transferred between strains and species by seven distinct subgroups of the Tn4401 element. We also found evidence for previously unrecognized resistance mechanisms that produced resistance when transformed into a susceptible genomic background. The extensive variation, together with evidence of transmission beyond limited clonal outbreaks, points to multiple unsampled transmission chains throughout the continuum of care, including asymptomatic carriage and transmission of CRE. This finding suggests that to control this threat, we need an aggressive approach to surveillance and isolation.


Assuntos
Carbapenêmicos/farmacologia , Elementos de DNA Transponíveis/genética , Surtos de Doenças , Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/efeitos dos fármacos , Fatores R/genética , Resistência beta-Lactâmica/genética , Proteínas de Bactérias/genética , Boston/epidemiologia , Células Clonais , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Infecção Hospitalar/transmissão , Enterobacteriaceae/enzimologia , Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/transmissão , Variação Genética , Genoma Bacteriano , Humanos , Estudos Prospectivos , Alinhamento de Sequência , Transformação Bacteriana , Resistência beta-Lactâmica/fisiologia , beta-Lactamases/genética
10.
Mol Microbiol ; 103(2): 347-365, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27775185

RESUMO

Fungal secondary metabolites (SMs) are extremely important in medicine and agriculture, but regulation of their biosynthesis is incompletely understood. We have developed a genetic screen in Aspergillus nidulans for negative regulators of fungal SM gene clusters and we have used this screen to isolate mutations that upregulate transcription of the non-ribosomal peptide synthetase gene required for nidulanin A biosynthesis. Several of these mutations are allelic and we have identified the mutant gene by genome sequencing. The gene, which we designate mcrA, is conserved but uncharacterized, and it encodes a putative transcription factor. Metabolite profiles of mcrA deletant, mcrA overexpressing, and parental strains reveal that mcrA regulates at least ten SM gene clusters. Deletion of mcrA stimulates SM production even in strains carrying a deletion of the SM regulator laeA, and deletion of mcrA homologs in Aspergillus terreus and Penicillum canescens alters the secondary metabolite profile of these organisms. Deleting mcrA in a genetic dereplication strain has allowed us to discover two novel compounds as well as an antibiotic not known to be produced by A. nidulans. Deletion of mcrA upregulates transcription of hundreds of genes including many that are involved in secondary metabolism, while downregulating a smaller number of genes.


Assuntos
Aspergillus nidulans/genética , Aspergillus nidulans/metabolismo , Peptídeo Sintases/genética , Peptídeo Sintases/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Família Multigênica , Mutação , Metabolismo Secundário , Deleção de Sequência , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional
11.
Anaerobe ; 38: 125-129, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26545740

RESUMO

Fusobacterium nucleatum is a strictly anaerobic, Gram negative bacterial species that has been associated with dental infections, pre-term labor, appendicitis, inflammatory bowel disease, and, more recently, colorectal cancer. The species is unusual in its phenotypic and genotypic heterogeneity, with some strains demonstrating a more virulent phenotype than others; however, as yet the genetic basis for these differences is not understood. Bacteriophage are known to contribute to the virulence phenotype of several bacterial species. In this work, we set out to characterize the bacteriophage associated with F. nucleatum subsp. animalis strain 7-1, a highly invasive isolate from the human gastrointestinal tract. As well, we used computational approaches to predict and compare bacteriophage signatures across available sequenced F. nucleatum genomes.


Assuntos
Bacteriófagos/genética , Fusobacterium nucleatum/virologia , Genoma Viral , Genômica , Bacteriófagos/classificação , Bacteriófagos/ultraestrutura , Análise por Conglomerados , Biologia Computacional/métodos , DNA Viral , Genômica/métodos , Humanos , Anotação de Sequência Molecular , Análise de Sequência de DNA
12.
Genome Biol Evol ; 6(10): 2866-82, 2014 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-25313016

RESUMO

Bacterial genomics has greatly expanded our understanding of microdiversification patterns within a species, but analyses at higher taxonomical levels are necessary to understand and predict the independent rise of pathogens in a genus. We have sampled, sequenced, and assessed the diversity of genomes of validly named and tentative species of the Acinetobacter genus, a clade including major nosocomial pathogens and biotechnologically important species. We inferred a robust global phylogeny and delimited several new putative species. The genus is very ancient and extremely diverse: Genomes of highly divergent species share more orthologs than certain strains within a species. We systematically characterized elements and mechanisms driving genome diversification, such as conjugative elements, insertion sequences, and natural transformation. We found many error-prone polymerases that may play a role in resistance to toxins, antibiotics, and in the generation of genetic variation. Surprisingly, temperate phages, poorly studied in Acinetobacter, were found to account for a significant fraction of most genomes. Accordingly, many genomes encode clustered regularly interspaced short palindromic repeats (CRISPR)-Cas systems with some of the largest CRISPR-arrays found so far in bacteria. Integrons are strongly overrepresented in Acinetobacter baumannii, which correlates with its frequent resistance to antibiotics. Our data suggest that A. baumannii arose from an ancient population bottleneck followed by population expansion under strong purifying selection. The outstanding diversification of the species occurred largely by horizontal transfer, including some allelic recombination, at specific hotspots preferentially located close to the replication terminus. Our work sets a quantitative basis to understand the diversification of Acinetobacter into emerging resistant and versatile pathogens.


Assuntos
Acinetobacter/genética , Genoma Bacteriano/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Genômica/métodos , Sequências Repetitivas Dispersas/genética , Filogenia
13.
Nucleic Acids Res ; 42(Database issue): D705-10, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24194595

RESUMO

The Aspergillus Genome Database (AspGD; http://www.aspgd.org) is a freely available web-based resource that was designed for Aspergillus researchers and is also a valuable source of information for the entire fungal research community. In addition to being a repository and central point of access to genome, transcriptome and polymorphism data, AspGD hosts a comprehensive comparative genomics toolbox that facilitates the exploration of precomputed orthologs among the 20 currently available Aspergillus genomes. AspGD curators perform gene product annotation based on review of the literature for four key Aspergillus species: Aspergillus nidulans, Aspergillus oryzae, Aspergillus fumigatus and Aspergillus niger. We have iteratively improved the structural annotation of Aspergillus genomes through the analysis of publicly available transcription data, mostly expressed sequenced tags, as described in a previous NAR Database article (Arnaud et al. 2012). In this update, we report substantive structural annotation improvements for A. nidulans, A. oryzae and A. fumigatus genomes based on recently available RNA-Seq data. Over 26 000 loci were updated across these species; although those primarily comprise the addition and extension of untranslated regions (UTRs), the new analysis also enabled over 1000 modifications affecting the coding sequence of genes in each target genome.


Assuntos
Aspergillus/genética , Bases de Dados Genéticas , Genoma Fúngico , Anotação de Sequência Molecular , Perfilação da Expressão Gênica , Genes Fúngicos , Internet , Análise de Sequência de RNA
14.
Nucleic Acids Res ; 41(15): 7387-400, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23761445

RESUMO

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vector-human and vector-parasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles-darlingi.


Assuntos
Anopheles/genética , Genoma de Inseto , Insetos Vetores/genética , Animais , Anopheles/classificação , Brasil , Cromossomos de Insetos/genética , Elementos de DNA Transponíveis , Evolução Molecular , Feminino , Variação Genética , Interações Hospedeiro-Parasita , Proteínas de Insetos/genética , Insetos Vetores/classificação , Resistência a Inseticidas , Inseticidas/farmacologia , Malária/parasitologia , Masculino , Anotação de Sequência Molecular , Filogenia , Sintenia , Transcriptoma
15.
BMC Microbiol ; 13: 91, 2013 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-23617571

RESUMO

BACKGROUND: Secondary metabolite production, a hallmark of filamentous fungi, is an expanding area of research for the Aspergilli. These compounds are potent chemicals, ranging from deadly toxins to therapeutic antibiotics to potential anti-cancer drugs. The genome sequences for multiple Aspergilli have been determined, and provide a wealth of predictive information about secondary metabolite production. Sequence analysis and gene overexpression strategies have enabled the discovery of novel secondary metabolites and the genes involved in their biosynthesis. The Aspergillus Genome Database (AspGD) provides a central repository for gene annotation and protein information for Aspergillus species. These annotations include Gene Ontology (GO) terms, phenotype data, gene names and descriptions and they are crucial for interpreting both small- and large-scale data and for aiding in the design of new experiments that further Aspergillus research. RESULTS: We have manually curated Biological Process GO annotations for all genes in AspGD with recorded functions in secondary metabolite production, adding new GO terms that specifically describe each secondary metabolite. We then leveraged these new annotations to predict roles in secondary metabolism for genes lacking experimental characterization. As a starting point for manually annotating Aspergillus secondary metabolite gene clusters, we used antiSMASH (antibiotics and Secondary Metabolite Analysis SHell) and SMURF (Secondary Metabolite Unknown Regions Finder) algorithms to identify potential clusters in A. nidulans, A. fumigatus, A. niger and A. oryzae, which we subsequently refined through manual curation. CONCLUSIONS: This set of 266 manually curated secondary metabolite gene clusters will facilitate the investigation of novel Aspergillus secondary metabolites.


Assuntos
Aspergillus/genética , Aspergillus/metabolismo , Produtos Biológicos/metabolismo , Vias Biossintéticas/genética , Biologia Computacional/métodos , Genes Fúngicos , Humanos , Família Multigênica
16.
Nat Genet ; 45(5): 495-500, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23525074

RESUMO

Loa loa, the African eyeworm, is a major filarial pathogen of humans. Unlike most filariae, L. loa does not contain the obligate intracellular Wolbachia endosymbiont. We describe the 91.4-Mb genome of L. loa and that of the related filarial parasite Wuchereria bancrofti and predict 14,907 L. loa genes on the basis of microfilarial RNA sequencing. By comparing these genomes to that of another filarial parasite, Brugia malayi, and to those of several other nematodes, we demonstrate synteny among filariae but not with nonparasitic nematodes. The L. loa genome encodes many immunologically relevant genes, as well as protein kinases targeted by drugs currently approved for use in humans. Despite lacking Wolbachia, L. loa shows no new metabolic synthesis or transport capabilities compared to other filariae. These results suggest that the role of Wolbachia in filarial biology is more subtle than previously thought and reveal marked differences between parasitic and nonparasitic nematodes.


Assuntos
Filariose/genética , Filarioidea/genética , Genes de Helmintos/genética , Genoma Helmíntico , Loa/genética , Proteínas Quinases/metabolismo , Wolbachia/genética , Animais , Brugia Malayi/genética , Filariose/parasitologia , Filarioidea/parasitologia , Humanos , Dados de Sequência Molecular , Filogenia , Simbiose , Wuchereria bancrofti/genética
17.
Proc Natl Acad Sci U S A ; 110(1): 240-5, 2013 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-23248304

RESUMO

The recent emergence of artemisinin-resistant Plasmodium falciparum malaria in western Cambodia could threaten prospects for malaria elimination. Identification of the genetic basis of resistance would provide tools for molecular surveillance, aiding efforts to contain resistance. Clinical trials of artesunate efficacy were conducted in Bangladesh, in northwestern Thailand near the Myanmar border, and at two sites in western Cambodia. Parasites collected from trial participants were genotyped at 8,079 single nucleotide polymorphisms (SNPs) using a P. falciparum-specific SNP array. Parasite genotypes were examined for signatures of recent positive selection and association with parasite clearance phenotypes to identify regions of the genome associated with artemisinin resistance. Four SNPs on chromosomes 10 (one), 13 (two), and 14 (one) were significantly associated with delayed parasite clearance. The two SNPs on chromosome 13 are in a region of the genome that appears to be under strong recent positive selection in Cambodia. The SNPs on chromosomes 10 and 13 lie in or near genes involved in postreplication repair, a DNA damage-tolerance pathway. Replication and validation studies are needed to refine the location of loci responsible for artemisinin resistance and to understand the mechanism behind it; however, two SNPs on chromosomes 10 and 13 may be useful markers of delayed parasite clearance in surveillance for artemisinin resistance in Southeast Asia.


Assuntos
Artemisininas/farmacologia , Resistência a Medicamentos/genética , Loci Gênicos/genética , Plasmodium falciparum/genética , Seleção Genética , Sudeste Asiático , Marcadores Genéticos/genética , Genótipo , Funções Verossimilhança , Razão de Chances , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo Único/genética , Análise de Componente Principal , Análise de Regressão
18.
PLoS Negl Trop Dis ; 6(6): e1708, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22724039

RESUMO

Human African Trypanosomiasis is a devastating disease caused by the parasite Trypanosoma brucei. Trypanosomes live extracellularly in both the tsetse fly and the mammal. Trypanosome surface proteins can directly interact with the host environment, allowing parasites to effectively establish and maintain infections. Glycosylphosphatidylinositol (GPI) anchoring is a common posttranslational modification associated with eukaryotic surface proteins. In T. brucei, three GPI-anchored major surface proteins have been identified: variant surface glycoproteins (VSGs), procyclic acidic repetitive protein (PARP or procyclins), and brucei alanine rich proteins (BARP). The objective of this study was to select genes encoding predicted GPI-anchored proteins with unknown function(s) from the T. brucei genome and characterize the expression profile of a subset during cyclical development in the tsetse and mammalian hosts. An initial in silico screen of putative T. brucei proteins by Big PI algorithm identified 163 predicted GPI-anchored proteins, 106 of which had no known functions. Application of a second GPI-anchor prediction algorithm (FragAnchor), signal peptide and trans-membrane domain prediction software resulted in the identification of 25 putative hypothetical proteins. Eighty-one gene products with hypothetical functions were analyzed for stage-regulated expression using semi-quantitative RT-PCR. The expression of most of these genes were found to be upregulated in trypanosomes infecting tsetse salivary gland and proventriculus tissues, and 38% were specifically expressed only by parasites infecting salivary gland tissues. Transcripts for all of the genes specifically expressed in salivary glands were also detected in mammalian infective metacyclic trypomastigotes, suggesting a possible role for these putative proteins in invasion and/or establishment processes in the mammalian host. These results represent the first large-scale report of the differential expression of unknown genes encoding predicted T. brucei surface proteins during the complete developmental cycle. This knowledge may form the foundation for the development of future novel transmission blocking strategies against metacyclic parasites.


Assuntos
Proteínas Ligadas por GPI/biossíntese , Perfilação da Expressão Gênica , Proteínas de Membrana/biossíntese , Proteínas de Protozoários/biossíntese , Trypanosoma brucei brucei/patogenicidade , Tripanossomíase Africana/parasitologia , Moscas Tsé-Tsé/parasitologia , Animais , Biologia Computacional , Trato Gastrointestinal/parasitologia , Humanos , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Glândulas Salivares/parasitologia , Trypanosoma brucei brucei/genética
19.
Genet Epidemiol ; 36(4): 360-7, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22508222

RESUMO

Large-scale genomics initiatives such as the HapMap project and the 1000-genomes rely on powerful bioinformatics support to assist data production and analysis. Contrastingly, few bioinformatics platforms oriented to smaller research groups exist to store, handle, share, and integrate data from different sources, as well as to assist these scientists to perform their analyses efficiently. We developed such a bioinformatics platform, DIVERGENOME, to assist population genetics and genetic epidemiology studies performed by small- to medium-sized research groups. The platform is composed of two integrated components, a relational database (DIVERGENOMEdb), and a set of tools to convert data formats as required by popular software in population genetics and genetic epidemiology (DIVERGENOMEtools). In DIVERGENOMEdb, information on genotypes, polymorphism, laboratory protocols, individuals, populations, and phenotypes is organized in projects. These can be queried according to permissions. Here, we validated DIVERGENOME through a use case regarding the analysis of SLC2A4 genetic diversity in human populations. DIVERGENOME, with its intuitive Web interface and automatic data loading capability, facilitates its use by individuals without bioinformatics background, allowing complex queries to be easily interrogated and straightforward data format conversions (not available in similar platforms). DIVERGENOME is open source, freely available, and can be accessed online (pggenetica.icb.ufmg.br/divergenome) or hosted locally.


Assuntos
Biologia Computacional/métodos , Epidemiologia Molecular , Algoritmos , Automação , Brasil , Bases de Dados Genéticas , Variação Genética , Genética Populacional , Genoma Humano , Estudo de Associação Genômica Ampla , Transportador de Glucose Tipo 4/genética , Humanos , Internet , Fenótipo , Software
20.
Proc Natl Acad Sci U S A ; 109(14): 5429-34, 2012 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-22431641

RESUMO

The malaria parasite, Plasmodium falciparum, and the human immune system have coevolved to ensure that the parasite is not eliminated and reinfection is not resisted. This relationship is likely mediated through a myriad of host-parasite interactions, although surprisingly few such interactions have been identified. Here we show that the 33-kDa fragment of P. falciparum merozoite surface protein 1 (MSP1(33)), an abundant protein that is shed during red blood cell invasion, binds to the proinflammatory protein, S100P. MSP1(33) blocks S100P-induced NFκB activation in monocytes and chemotaxis in neutrophils. Remarkably, S100P binds to both dimorphic alleles of MSP1, estimated to have diverged >27 Mya, suggesting an ancient, conserved relationship between these parasite and host proteins that may serve to attenuate potentially damaging inflammatory responses.


Assuntos
Proteínas de Ligação ao Cálcio/antagonistas & inibidores , Proteína 1 de Superfície de Merozoito/fisiologia , Proteínas de Neoplasias/antagonistas & inibidores , Plasmodium falciparum/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Ligação ao Cálcio/química , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Humanos , Microscopia Confocal , Dados de Sequência Molecular , Proteínas de Neoplasias/química , Homologia de Sequência de Aminoácidos , Ressonância de Plasmônio de Superfície
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