Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Mol Cell ; 83(24): 4445-4460.e7, 2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-37995689

RESUMEN

The metazoan-specific Integrator complex catalyzes 3' end processing of small nuclear RNAs (snRNAs) and premature termination that attenuates the transcription of many protein-coding genes. Integrator has RNA endonuclease and protein phosphatase activities, but it remains unclear if both are required for complex function. Here, we show IntS6 (Integrator subunit 6) over-expression blocks Integrator function at a subset of Drosophila protein-coding genes, although having no effect on snRNAs or attenuation of other loci. Over-expressed IntS6 titrates protein phosphatase 2A (PP2A) subunits, thereby only affecting gene loci where phosphatase activity is necessary for Integrator function. IntS6 functions analogous to a PP2A regulatory B subunit as over-expression of canonical B subunits, which do not bind Integrator, is also sufficient to inhibit Integrator activity. These results show that the phosphatase module is critical at only a subset of Integrator-regulated genes and point to PP2A recruitment as a tunable step that modulates transcription termination efficiency.


Asunto(s)
Proteínas de Drosophila , Terminación de la Transcripción Genética , Animales , ARN , ARN Polimerasa II/genética , ARN Polimerasa II/metabolismo , ARN Nuclear Pequeño/genética , Factores de Transcripción/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster
2.
Nature ; 630(8016): 429-436, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38811738

RESUMEN

Infections caused by Gram-negative pathogens are increasingly prevalent and are typically treated with broad-spectrum antibiotics, resulting in disruption of the gut microbiome and susceptibility to secondary infections1-3. There is a critical need for antibiotics that are selective both for Gram-negative bacteria over Gram-positive bacteria, as well as for pathogenic bacteria over commensal bacteria. Here we report the design and discovery of lolamicin, a Gram-negative-specific antibiotic targeting the lipoprotein transport system. Lolamicin has activity against a panel of more than 130 multidrug-resistant clinical isolates, shows efficacy in multiple mouse models of acute pneumonia and septicaemia infection, and spares the gut microbiome in mice, preventing secondary infection with Clostridioides difficile. The selective killing of pathogenic Gram-negative bacteria by lolamicin is a consequence of low sequence homology for the target in pathogenic bacteria versus commensals; this doubly selective strategy can be a blueprint for the development of other microbiome-sparing antibiotics.


Asunto(s)
Antibacterianos , Descubrimiento de Drogas , Microbioma Gastrointestinal , Bacterias Gramnegativas , Infecciones por Bacterias Gramnegativas , Simbiosis , Animales , Femenino , Humanos , Masculino , Ratones , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Línea Celular , Clostridioides difficile/efectos de los fármacos , Infecciones por Clostridium/microbiología , Infecciones por Clostridium/tratamiento farmacológico , Modelos Animales de Enfermedad , Diseño de Fármacos , Farmacorresistencia Bacteriana Múltiple , Microbioma Gastrointestinal/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Infecciones por Bacterias Gramnegativas/microbiología , Lipoproteínas/metabolismo , Ratones Endogámicos C57BL , Transporte de Proteínas/efectos de los fármacos , Sepsis/microbiología , Sepsis/tratamiento farmacológico , Especificidad por Sustrato , Simbiosis/efectos de los fármacos
3.
Genes Dev ; 35(23-24): 1595-1609, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34819352

RESUMEN

Binding of microRNAs (miRNAs) to mRNAs normally results in post-transcriptional repression of gene expression. However, extensive base-pairing between miRNAs and target RNAs can trigger miRNA degradation, a phenomenon called target RNA-directed miRNA degradation (TDMD). Here, we systematically analyzed Argonaute-CLASH (cross-linking, ligation, and sequencing of miRNA-target RNA hybrids) data and identified numerous candidate TDMD triggers, focusing on their ability to induce nontemplated nucleotide addition at the miRNA 3' end. When exogenously expressed in various cell lines, eight triggers induce degradation of corresponding miRNAs. Both the TDMD base-pairing and surrounding sequences are essential for TDMD. CRISPR knockout of endogenous trigger or ZSWIM8, a ubiquitin ligase essential for TDMD, reduced miRNA degradation. Furthermore, degradation of miR-221 and miR-222 by a trigger in BCL2L11, which encodes a proapoptotic protein, enhances apoptosis. Therefore, we uncovered widespread TDMD triggers in target RNAs and demonstrated an example that could functionally cooperate with the encoded protein.


Asunto(s)
MicroARNs , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Emparejamiento Base , MicroARNs/genética , MicroARNs/metabolismo , Estabilidad del ARN/genética , ARN Mensajero/genética
4.
J Virol ; 98(1): e0161823, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38174928

RESUMEN

The global evolution of SARS-CoV-2 depends in part upon the evolutionary dynamics within individual hosts with varying immune histories. To characterize the within-host evolution of acute SARS-CoV-2 infection, we sequenced saliva and nasal samples collected daily from vaccinated and unvaccinated individuals early during infection. We show that longitudinal sampling facilitates high-confidence genetic variant detection and reveals evolutionary dynamics missed by less-frequent sampling strategies. Within-host dynamics in both unvaccinated and vaccinated individuals appeared largely stochastic; however, in rare cases, minor genetic variants emerged to frequencies sufficient for forward transmission. Finally, we detected significant genetic compartmentalization of viral variants between saliva and nasal swab sample sites in many individuals. Altogether, these data provide a high-resolution profile of within-host SARS-CoV-2 evolutionary dynamics.IMPORTANCEWe detail the within-host evolutionary dynamics of SARS-CoV-2 during acute infection in 31 individuals using daily longitudinal sampling. We characterized patterns of mutational accumulation for unvaccinated and vaccinated individuals, and observed that temporal variant dynamics in both groups were largely stochastic. Comparison of paired nasal and saliva samples also revealed significant genetic compartmentalization between tissue environments in multiple individuals. Our results demonstrate how selection, genetic drift, and spatial compartmentalization all play important roles in shaping the within-host evolution of SARS-CoV-2 populations during acute infection.


Asunto(s)
Evolución Molecular , Flujo Genético , SARS-CoV-2 , Humanos , COVID-19/virología , Nariz/virología , Saliva/virología , SARS-CoV-2/genética , Masculino , Femenino , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad
5.
PLoS Genet ; 17(12): e1009934, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34914716

RESUMEN

MicroRNAs (miRNA) are short non-coding RNAs widely implicated in gene regulation. Most metazoan miRNAs utilize the RNase III enzymes Drosha and Dicer for biogenesis. One notable exception is the RNA polymerase II transcription start sites (TSS) miRNAs whose biogenesis does not require Drosha. The functional importance of the TSS-miRNA biogenesis is uncertain. To better understand the function of TSS-miRNAs, we applied a modified Crosslinking, Ligation, and Sequencing of Hybrids on Argonaute (AGO-qCLASH) to identify the targets for TSS-miRNAs in HCT116 colorectal cancer cells with or without DROSHA knockout. We observed that miR-320a hybrids dominate in TSS-miRNA hybrids identified by AGO-qCLASH. Targets for miR-320a are enriched for the eIF2 signaling pathway, a downstream component of the unfolded protein response. Consistently, in miR-320a mimic- and antagomir- transfected cells, differentially expressed gene products are associated with eIF2 signaling. Within the AGO-qCLASH data, we identified the endoplasmic reticulum (ER) chaperone calnexin as a direct miR-320a down-regulated target, thus connecting miR-320a to the unfolded protein response. During ER stress, but not amino acid deprivation, miR-320a up-regulates ATF4, a critical transcription factor for resolving ER stress. In summary, our study investigates the targetome of the TSS-miRNAs in colorectal cancer cells and establishes miR-320a as a regulator of unfolded protein response.


Asunto(s)
Factor de Transcripción Activador 4/genética , Neoplasias Colorrectales/genética , MicroARNs/genética , Ribonucleasa III/genética , Antagomirs/genética , Proteínas Argonautas/genética , Calnexina/genética , Movimiento Celular/genética , Proliferación Celular/genética , Neoplasias Colorrectales/patología , ARN Helicasas DEAD-box/genética , Retículo Endoplásmico/genética , Estrés del Retículo Endoplásmico/genética , Factor 2 Eucariótico de Iniciación/genética , Técnicas de Inactivación de Genes , Células HCT116 , Humanos , Transducción de Señal/genética , Sitio de Iniciación de la Transcripción
6.
RNA ; 27(6): 694-709, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33795480

RESUMEN

MicroRNAs (miRNAs) are small noncoding RNAs that function as critical posttranscriptional regulators in various biological processes. While most miRNAs are generated from processing of long primary transcripts via sequential Drosha and Dicer cleavage, some miRNAs that bypass Drosha cleavage can be transcribed as part of another small noncoding RNA. Here, we develop the target-oriented miRNA discovery (TOMiD) bioinformatic analysis method to identify Drosha-independent miRNAs from Argonaute crosslinking and sequencing of hybrids (Ago-CLASH) data sets. Using this technique, we discovered a novel miRNA derived from a primate specific noncoding RNA, the small NF90 associated RNA A (snaR-A). The miRNA derived from snaR-A (miR-snaR) arises independently of Drosha processing but requires Exportin-5 and Dicer for biogenesis. We identify that miR-snaR is concurrently up-regulated with the full snaR-A transcript in cancer cells. Functionally, miR-snaR associates with Ago proteins and targets NME1, a key metastasis inhibitor, contributing to snaR-A's role in promoting cancer cell migration. Our findings suggest a functional link between a novel miRNA and its precursor noncoding RNA.


Asunto(s)
Biología Computacional/métodos , MicroARNs/metabolismo , ARN Largo no Codificante/genética , Regiones no Traducidas 3' , Movimiento Celular , ARN Helicasas DEAD-box/metabolismo , Células HCT116 , Células HEK293 , Humanos , Carioferinas/metabolismo , Células MCF-7 , Nucleósido Difosfato Quinasas NM23/antagonistas & inhibidores , Nucleósido Difosfato Quinasas NM23/genética , Neoplasias/patología , ARN Largo no Codificante/metabolismo , Ribonucleasa III/metabolismo
7.
Int J Mol Sci ; 24(8)2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-37108472

RESUMEN

Root-lesion nematodes (genus Pratylenchus) belong to a diverse group of plant-parasitic nematodes (PPN) with a worldwide distribution. Despite being an economically important PPN group of more than 100 species, genome information related to Pratylenchus genus is scarcely available. Here, we report the draft genome assembly of Pratylenchus scribneri generated on the PacBio Sequel IIe System using the ultra-low DNA input HiFi sequencing workflow. The final assembly created using 500 nematodes consisted of 276 decontaminated contigs, with an average contig N50 of 1.72 Mb and an assembled draft genome size of 227.24 Mb consisting of 51,146 predicted protein sequences. The benchmarking universal single-copy ortholog (BUSCO) analysis with 3131 nematode BUSCO groups indicated that 65.4% of the BUSCOs were complete, whereas 24.0%, 41.4%, and 1.8% were single-copy, duplicated, and fragmented, respectively, and 32.8% were missing. The outputs from GenomeScope2 and Smudgeplots converged towards a diploid genome for P. scribneri. The data provided here will facilitate future studies on host plant-nematode interactions and crop protection at the molecular level.


Asunto(s)
Parásitos , Tylenchoidea , Animales , Anotación de Secuencia Molecular , Análisis de Secuencia de ADN , Genoma , Secuencia de Bases , Tylenchoidea/genética , Parásitos/genética
8.
PLoS Comput Biol ; 17(2): e1008640, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33630830

RESUMEN

With more microbiome studies being conducted by African-based research groups, there is an increasing demand for knowledge and skills in the design and analysis of microbiome studies and data. However, high-quality bioinformatics courses are often impeded by differences in computational environments, complicated software stacks, numerous dependencies, and versions of bioinformatics tools along with a lack of local computational infrastructure and expertise. To address this, H3ABioNet developed a 16S rRNA Microbiome Intermediate Bioinformatics Training course, extending its remote classroom model. The course was developed alongside experienced microbiome researchers, bioinformaticians, and systems administrators, who identified key topics to address. Development of containerised workflows has previously been undertaken by H3ABioNet, and Singularity containers were used here to enable the deployment of a standard replicable software stack across different hosting sites. The pilot ran successfully in 2019 across 23 sites registered in 11 African countries, with more than 200 participants formally enrolled and 106 volunteer staff for onsite support. The pulling, running, and testing of the containers, software, and analyses on various clusters were performed prior to the start of the course by hosting classrooms. The containers allowed the replication of analyses and results across all participating classrooms running a cluster and remained available posttraining ensuring analyses could be repeated on real data. Participants thus received the opportunity to analyse their own data, while local staff were trained and supported by experienced experts, increasing local capacity for ongoing research support. This provides a model for delivering topic-specific bioinformatics courses across Africa and other remote/low-resourced regions which overcomes barriers such as inadequate infrastructures, geographical distance, and access to expertise and educational materials.


Asunto(s)
Biología Computacional/educación , Biología Computacional/métodos , ARN Ribosómico 16S , Programas Informáticos , África , Algoritmos , Curriculum , Genoma Humano , Geografía , Humanos , Microbiota
9.
RNA ; 24(12): 1871-1877, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30201850

RESUMEN

Northern blot analysis detects RNA molecules immobilized on nylon membranes through hybridization with radioactive 32P-labeled DNA or RNA oligonucleotide probes. Alternatively, nonradioactive northern blot relies on chemiluminescent reactions triggered by horseradish peroxidase (HRP) conjugated probes. The use of regulated radioactive material and the complexity of chemiluminescent reactions and detection have hampered the adoption of northern blot techniques by the wider biomedical research community. Here, we describe a sensitive and straightforward nonradioactive northern blot method, which utilizes near-infrared (IR) fluorescent dye-labeled probes (irNorthern). We found that irNorthern has a detection limit of ∼0.05 femtomoles (fmol), which is slightly less sensitive than 32P-Northern. However, we found that the IR dye-labeled probe maintains the sensitivity after multiple usages as well as long-term storage. We also present alternative irNorthern methods using a biotinylated DNA probe, a DNA probe labeled by terminal transferase, or an RNA probe labeled during in vitro transcription. Furthermore, utilization of different IR dyes allows multiplex detection of different RNA species. Therefore, irNorthern represents a more convenient and versatile tool for RNA detection compared to traditional northern blot analysis.


Asunto(s)
Northern Blotting/métodos , Colorantes Fluorescentes/química , Hibridación de Ácido Nucleico/métodos , ARN/aislamiento & purificación , Sondas de ADN/química , ARN/química , Sondas ARN/química
10.
J Virol ; 93(11)2019 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-30867305

RESUMEN

The mechanisms and consequences of defective interfering particle (DIP) formation during influenza virus infection remain poorly understood. The development of next-generation sequencing (NGS) technologies has made it possible to identify large numbers of DIP-associated sequences, providing a powerful tool to better understand their biological relevance. However, NGS approaches pose numerous technical challenges, including the precise identification and mapping of deletion junctions in the presence of frequent mutation and base-calling errors, and the potential for numerous experimental and computational artifacts. Here, we detail an Illumina-based sequencing framework and bioinformatics pipeline capable of generating highly accurate and reproducible profiles of DIP-associated junction sequences. We use a combination of simulated and experimental control data sets to optimize pipeline performance and demonstrate the absence of significant artifacts. Finally, we use this optimized pipeline to reveal how the patterns of DIP-associated junction formation differ between different strains and subtypes of influenza A and B viruses and to demonstrate how these data can provide insight into mechanisms of DIP formation. Overall, this work provides a detailed roadmap for high-resolution profiling and analysis of DIP-associated sequences within influenza virus populations.IMPORTANCE Influenza virus defective interfering particles (DIPs) that harbor internal deletions within their genomes occur naturally during infection in humans and during cell culture. They have been hypothesized to influence the pathogenicity of the virus; however, their specific function remains elusive. The accurate detection of DIP-associated deletion junctions is crucial for understanding DIP biology but is complicated by an array of technical issues that can bias or confound results. Here, we demonstrate a combined experimental and computational framework for detecting DIP-associated deletion junctions using next-generation sequencing (NGS). We detail how to validate pipeline performance and provide the bioinformatics pipeline for groups interested in using it. Using this optimized pipeline, we detect hundreds of distinct deletion junctions generated during infection with a diverse panel of influenza viruses and use these data to test a long-standing hypothesis concerning the molecular details of DIP formation.


Asunto(s)
Biología Computacional/métodos , Virus Defectuosos/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Genoma Viral , Humanos , Virus de la Influenza A/genética , Virus de la Influenza B/genética , Gripe Humana/virología , Orthomyxoviridae/genética , Infecciones por Orthomyxoviridae/genética , Eliminación de Secuencia , Replicación Viral
11.
Appl Environ Microbiol ; 85(7)2019 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-30737348

RESUMEN

In the human gut, Clostridium scindens ATCC 35704 is a predominant bacterium and one of the major bile acid 7α-dehydroxylating anaerobes. While this organism is well-studied relative to bile acid metabolism, little is known about the basic nutrition and physiology of C. scindens ATCC 35704. To determine the amino acid and vitamin requirements of C. scindens, the leave-one-out (one amino acid group or vitamin) technique was used to eliminate the nonessential amino acids and vitamins. With this approach, the amino acid tryptophan and three vitamins (riboflavin, pantothenate, and pyridoxal) were found to be required for the growth of C. scindens In the newly developed defined medium, C. scindens fermented glucose mainly to ethanol, acetate, formate, and H2. The genome of C. scindens ATCC 35704 was completed through PacBio sequencing. Pathway analysis of the genome sequence coupled with transcriptome sequencing (RNA-Seq) under defined culture conditions revealed consistency with the growth requirements and end products of glucose metabolism. Induction with bile acids revealed complex and differential responses to cholic acid and deoxycholic acid, including the expression of potentially novel bile acid-inducible genes involved in cholic acid metabolism. Responses to toxic deoxycholic acid included expression of genes predicted to be involved in DNA repair, oxidative stress, cell wall maintenance/metabolism, chaperone synthesis, and downregulation of one-third of the genome. These analyses provide valuable insight into the overall biology of C. scindens which may be important in treatment of disease associated with increased colonic secondary bile acids.IMPORTANCEC. scindens is one of a few identified gut bacterial species capable of converting host cholic acid into disease-associated secondary bile acids such as deoxycholic acid. The current work represents an important advance in understanding the nutritional requirements and response to bile acids of the medically important human gut bacterium, C. scindens ATCC 35704. A defined medium has been developed which will further the understanding of bile acid metabolism in the context of growth substrates, cofactors, and other metabolites in the vertebrate gut. Analysis of the complete genome supports the nutritional requirements reported here. Genome-wide transcriptomic analysis of gene expression in the presence of cholic acid and deoxycholic acid provides a unique insight into the complex response of C. scindens ATCC 35704 to primary and secondary bile acids. Also revealed are genes with the potential to function in bile acid transport and metabolism.


Asunto(s)
Ácidos y Sales Biliares/metabolismo , Clostridiales/genética , Clostridiales/metabolismo , Microbioma Gastrointestinal , Necesidades Nutricionales , Secuenciación Completa del Genoma , Aminoácidos/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Metabolismo de los Hidratos de Carbono , Ácido Cólico/metabolismo , Clostridiales/crecimiento & desarrollo , Medios de Cultivo , Reparación del ADN , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Ácido Desoxicólico/metabolismo , Fermentación , Humanos , Hidroxilación , Análisis de Secuencia de ARN
12.
Plant Cell ; 28(11): 2700-2714, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27803309

RESUMEN

Intense artificial selection over the last 100 years has produced elite maize (Zea mays) inbred lines that combine to produce high-yielding hybrids. To further our understanding of how genome and transcriptome variation contribute to the production of high-yielding hybrids, we generated a draft genome assembly of the inbred line PH207 to complement and compare with the existing B73 reference sequence. B73 is a founder of the Stiff Stalk germplasm pool, while PH207 is a founder of Iodent germplasm, both of which have contributed substantially to the production of temperate commercial maize and are combined to make heterotic hybrids. Comparison of these two assemblies revealed over 2500 genes present in only one of the two genotypes and 136 gene families that have undergone extensive expansion or contraction. Transcriptome profiling revealed extensive expression variation, with as many as 10,564 differentially expressed transcripts and 7128 transcripts expressed in only one of the two genotypes in a single tissue. Genotype-specific genes were more likely to have tissue/condition-specific expression and lower transcript abundance. The availability of a high-quality genome assembly for the elite maize inbred PH207 expands our knowledge of the breadth of natural genome and transcriptome variation in elite maize inbred lines across heterotic pools.


Asunto(s)
Genoma de Planta/genética , Transcriptoma/genética , Zea mays/genética , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/genética , Variación Genética/genética
13.
Exerc Sport Sci Rev ; 47(2): 75-85, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30883471

RESUMEN

The gastrointestinal tract contains trillions of microbes (collectively known as the gut microbiota) that play essential roles in host physiology and health. Studies from our group and others have demonstrated that exercise independently alters the composition and functional capacity of the gut microbiota. Here, we review what is known about the gut microbiota, how it is studied, and how it is influenced by exercise training and discuss the potential mechanisms and implications for human health and disease.


Asunto(s)
Ejercicio Físico , Microbioma Gastrointestinal , Tracto Gastrointestinal/fisiología , Animales , Humanos
14.
BMC Genomics ; 19(1): 216, 2018 03 26.
Artículo en Inglés | MEDLINE | ID: mdl-29580210

RESUMEN

BACKGROUND: Aggression is influenced by individual variation in temperament as well as behavioral plasticity in response to adversity. DNA methylation is stably maintained over time, but also reversible in response to specific environmental conditions, and may thus be a neuromolecular regulator of both of these processes. A previous study reported DNA methylation differences between aggressive Africanized and gentle European honey bees. We investigated whether threat-induced aggression altered DNA methylation profiles in the honey bee brain in response to a behavioral stimulus (aggression-provoking intruder bee or inert control). We sampled five minutes and two hours after stimulus exposure to examine the effect of time on epigenetic profiles of aggression. RESULTS: There were DNA methylation differences between aggressive and control bees for individual cytosine-guanine dinucleotides (CpGs) across the genome. Eighteen individual CpG sites showed significant difference between aggressive and control bees 120 min post stimulus. For clusters of CpGs, we report four genomic regions differentially methylated between aggressive and control bees at the 5-min time point, and 50 regions differentially methylated at the120-minute time point following intruder exposure. Differential methylation occurred at genes involved in neural plasticity, chromatin remodeling and hormone signaling. Additionally, there was a significant overlap of differential methylation with previously published epigenetic differences that distinguish aggressive Africanized and gentle European honey bees, suggesting an evolutionarily conserved use of brain DNA methylation in the regulation of aggression. Lastly, we identified individually statistically suggestive CpGs that as a group were significantly associated with differentially expressed genes underlying aggressive behavior and also co-localize with binding sites of transcription factors involved in neuroplasticity or neurodevelopment. CONCLUSIONS: There were DNA methylation differences in the brain associated with response to an intruder. These differences increased in number a few hours after the initial exposure and overlap with previously reported aggression-associated genes and neurobiologically relevant transcription factor binding sites. Many DNA methylation differences that occurred in association with the expression of aggression in real time also exist between Africanized bees and European bees, suggesting an evolutionarily conserved role for epigenetic regulation in aggressive behavior.


Asunto(s)
Abejas/fisiología , Proteínas de Insectos/genética , Agresión , Animales , Abejas/genética , Conducta Animal , Evolución Biológica , Encéfalo/fisiología , Metilación de ADN , Epigénesis Genética , Regulación de la Expresión Génica , Genoma , Territorialidad
15.
PLoS Comput Biol ; 13(6): e1005419, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28570565

RESUMEN

The H3ABioNet pan-African bioinformatics network, which is funded to support the Human Heredity and Health in Africa (H3Africa) program, has developed node-assessment exercises to gauge the ability of its participating research and service groups to analyze typical genome-wide datasets being generated by H3Africa research groups. We describe a framework for the assessment of computational genomics analysis skills, which includes standard operating procedures, training and test datasets, and a process for administering the exercise. We present the experiences of 3 research groups that have taken the exercise and the impact on their ability to manage complex projects. Finally, we discuss the reasons why many H3ABioNet nodes have declined so far to participate and potential strategies to encourage them to do so.


Asunto(s)
Población Negra/genética , Bases de Datos Genéticas , Genómica/métodos , Sistemas de Administración de Bases de Datos , Países en Desarrollo , Humanos , Nigeria , Sudáfrica
16.
BMC Genomics ; 17: 147, 2016 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-26920945

RESUMEN

BACKGROUND: Diet and particularly dietary fibres have an impact on the gut microbiome and play an important role in human health and disease. Pectin is a highly consumed dietary fibre found in fruits and vegetables and is also a widely used additive in the food industry. Yet there is no information on the effect of pectin on the human gut microbiome. Likewise, little is known on gut pectinolytic bacteria and their enzyme systems. This study was undertaken to investigate the mechanisms of pectin degradation by the prominent human gut symbiont Bacteroides xylanisolvens. RESULTS: Transcriptomic analyses of B. xylanisolvens XB1A grown on citrus and apple pectins at mid- and late-log phases highlighted six polysaccharide utilization loci (PUL) that were overexpressed on pectin relative to glucose. The PUL numbers used in this report are those given by Terrapon et al. (Bioinformatics 31(5):647-55, 2015) and found in the PUL database: http://www.cazy.org/PULDB/. Based on their CAZyme composition, we propose that PUL 49 and 50, the most overexpressed PULs on both pectins and at both growth phases, are involved in homogalacturonan (HG) and type I rhamnogalacturonan (RGI) degradation, respectively. PUL 13 and PUL 2 could be involved in the degradation of arabinose-containing side chains and of type II rhamnogalacturonan (RGII), respectively. Considering that HG is the most abundant moiety (>70%) within pectin, the importance of PUL 49 was further investigated by insertion mutagenesis into the susC-like gene. The insertion blocked transcription of the susC-like and the two downstream genes (susD-like/FnIII). The mutant showed strong growth reduction, thus confirming that PUL 49 plays a major role in pectin degradation. CONCLUSION: This study shows the existence of six PULs devoted to pectin degradation by B. xylanisolvens, one of them being particularly important in this function. Hence, this species deploys a very complex enzymatic machinery that probably reflects the structural complexity of pectin. Our findings also highlight the metabolic plasticity of B. xylanisolvens towards dietary fibres that contributes to its competitive fitness within the human gut ecosystem. Wider functional and ecological studies are needed to understand how dietary fibers and especially plant cell wall polysaccharides drive the composition and metabolism of the fibrolytic and non-fibrolytic community within the gut microbial ecosystem.


Asunto(s)
Bacteroides/metabolismo , Fibras de la Dieta/metabolismo , Pectinas/metabolismo , Análisis de Secuencia de ARN/métodos , Bacteroides/genética , Citrus/química , Sitios Genéticos , Malus/química , Mutagénesis , ARN Bacteriano/genética , Transcriptoma
17.
BMC Genomics ; 17: 326, 2016 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-27142817

RESUMEN

BACKGROUND: Plant cell wall (PCW) polysaccharides and especially xylans constitute an important part of human diet. Xylans are not degraded by human digestive enzymes in the upper digestive tract and therefore reach the colon where they are subjected to extensive degradation by some members of the symbiotic microbiota. Xylanolytic bacteria are the first degraders of these complex polysaccharides and they release breakdown products that can have beneficial effects on human health. In order to understand better how these bacteria metabolize xylans in the colon, this study was undertaken to investigate xylan breakdown by the prominent human gut symbiont Bacteroides xylanisolvens XB1A(T). RESULTS: Transcriptomic analyses of B. xylanisolvens XB1A(T) grown on insoluble oat-spelt xylan (OSX) at mid- and late-log phases highlighted genes in a polysaccharide utilization locus (PUL), hereafter called PUL 43, and genes in a fragmentary remnant of another PUL, hereafter referred to as rPUL 70, which were highly overexpressed on OSX relative to glucose. Proteomic analyses supported the up-regulation of several genes belonging to PUL 43 and showed the important over-production of a CBM4-containing GH10 endo-xylanase. We also show that PUL 43 is organized in two operons and that the knockout of the PUL 43 sensor/regulator HTCS gene blocked the growth of the mutant on insoluble OSX and soluble wheat arabinoxylan (WAX). The mutation not only repressed gene expression in the PUL 43 operons but also repressed gene expression in rPUL 70. CONCLUSION: This study shows that xylan degradation by B. xylanisolvens XB1A(T) is orchestrated by one PUL and one PUL remnant that are linked at the transcriptional level. Coupled to studies on other xylanolytic Bacteroides species, our data emphasize the importance of one peculiar CBM4-containing GH10 endo-xylanase in xylan breakdown and that this modular enzyme may be used as a functional marker of xylan degradation in the human gut. Our results also suggest that B. xylanisolvens XB1A(T) has specialized in the degradation of xylans of low complexity. This functional feature may provide a niche to all xylanolytic bacteria harboring similar PULs. Further functional and ecological studies on fibrolytic Bacteroides species are needed to better understand their role in dietary fiber degradation and their impact on intestinal health.


Asunto(s)
Proteínas Bacterianas/genética , Bacteroides/crecimiento & desarrollo , Perfilación de la Expresión Génica/métodos , Análisis de Secuencia de ARN/métodos , Xilanos/metabolismo , Proteínas Bacterianas/metabolismo , Bacteroides/genética , Bacteroides/metabolismo , Tracto Gastrointestinal/microbiología , Regulación Bacteriana de la Expresión Génica , Humanos , Familia de Multigenes , Operón , Proteínas de Plantas/metabolismo , Proteómica/métodos
18.
BMC Genomics ; 16: 395, 2015 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-25986459

RESUMEN

BACKGROUND: Leafy spurge (Euphorbia esula) is a perennial weed that is considered glyphosate tolerant, which is partially attributed to escape through establishment of new vegetative shoots from an abundance of underground adventitious buds. Leafy spurge plants treated with sub-lethal concentrations of foliar-applied glyphosate produce new vegetative shoots with reduced main stem elongation and increased branching. Processes associated with the glyphosate-induced phenotype were determined by RNAseq using aerial shoots derived from crown buds of glyphosate-treated and -untreated plants. Comparison between transcript abundance and accumulation of shikimate or phytohormones (abscisic acid, auxin, cytokinins, and gibberellins) from these same samples was also done to reveal correlations. RESULTS: Transcriptome assembly and analyses confirmed differential abundance among 12,918 transcripts (FDR ≤ 0.05) and highlighted numerous processes associated with shoot apical meristem maintenance and stem growth, which is consistent with the increased number of actively growing meristems in response to glyphosate. Foliar applied glyphosate increased shikimate abundance in crown buds prior to decapitation of aboveground shoots, which induces growth from these buds, indicating that 5-enolpyruvylshikimate 3-phosphate (EPSPS) the target site of glyphosate was inhibited. However, abundance of shikimate was similar in a subsequent generation of aerial shoots derived from crown buds of treated and untreated plants, suggesting EPSPS is no longer inhibited or abundance of shikimate initially observed in crown buds dissipated over time. Overall, auxins, gibberellins (precursors and catabolites of bioactive gibberellins), and cytokinins (precursors and bioactive cytokinins) were more abundant in the aboveground shoots derived from glyphosate-treated plants. CONCLUSION: Based on the overall data, we propose that the glyphosate-induced phenotype resulted from complex interactions involving shoot apical meristem maintenance, hormone biosynthesis and signaling (auxin, cytokinins, gibberellins, and strigolactones), cellular transport, and detoxification mechanisms.


Asunto(s)
Euphorbia , Glicina/análogos & derivados , Reguladores del Crecimiento de las Plantas/metabolismo , Tallos de la Planta/crecimiento & desarrollo , Transcriptoma/efectos de los fármacos , Ácido Corísmico/biosíntesis , Euphorbia/efectos de los fármacos , Euphorbia/genética , Euphorbia/crecimiento & desarrollo , Glicina/farmacología , Herbicidas/farmacología , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/genética , Brotes de la Planta/metabolismo , Tallos de la Planta/efectos de los fármacos , Tallos de la Planta/genética , Tallos de la Planta/metabolismo , Análisis de Secuencia de ARN , Ácido Shikímico/metabolismo , Transducción de Señal/efectos de los fármacos , Glifosato
19.
Bioinformatics ; 30(13): 1926-7, 2014 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-24618462

RESUMEN

The development of bioinformatic solutions for microbial ecology in Perl is limited by the lack of modules to represent and manipulate microbial community profiles from amplicon and meta-omics studies. Here we introduce Bio-Community, an open-source, collaborative toolkit that extends BioPerl. Bio-Community interfaces with commonly used programs using various file formats, including BIOM, and provides operations such as rarefaction and taxonomic summaries. Bio-Community will help bioinformaticians to quickly piece together custom analysis pipelines and develop novel software. Availability an implementation: Bio-Community is cross-platform Perl code available from http://search.cpan.org/dist/Bio-Community under the Perl license. A readme file describes software installation and how to contribute.


Asunto(s)
Ecosistema , Biología Computacional/métodos , Humanos , Técnicas Microbiológicas , Microbiología , Diseño de Software
20.
F1000Res ; 12: 1568, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38076297

RESUMEN

The 24th annual Bioinformatics Open Source Conference ( BOSC 2023) was part of the 2023i conference on Intelligent Systems for Molecular Biology and the European Conference on Computational Biology (ISMB/ECCB 2023). Launched in 2000 and held yearly since, BOSC is the premier meeting covering open-source bioinformatics and open science. Like ISMB 2022, the 2023 meeting was a hybrid conference, with the in-person component hosted in Lyon, France. ISMB/ECCB attracted a near-record number of attendees, with over 2100 in person and about 900 more online. Approximately 200 people participated in BOSC sessions. In addition to 43 talks and 49 posters, BOSC featured two keynotes: Sara El-Gebali, who spoke about "A New Odyssey: Pioneering the Future of Scientific Progress Through Open Collaboration", and Joseph Yracheta, who spoke about "The Dissonance between Scientific Altruism & Capitalist Extraction: The Zero Trust and Federated Data Sovereignty Solution." Once again, a joint session brought together BOSC and the Bio-Ontologies COSI. The conference ended with a panel on Open and Ethical Data Sharing. As in prior years, BOSC was preceded by a CollaborationFest, a collaborative work event that brought together about 40 participants interested in synergistically combining ideas, shaping project plans, developing software, and more.


Asunto(s)
Biología Computacional , Programas Informáticos , Humanos , Difusión de la Información
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA