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1.
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
2.
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
3.
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
4.
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
5.
J Anim Sci ; 100(10)2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35965387

RESUMEN

Purported benefits of human-grade pet foods include reduced inflammation, enhanced coat quality, and improved gut health, but research is scarce. Therefore, we compared gene expression, skin and coat health measures, and the fecal microbiome of dogs consuming a mildly cooked human-grade or extruded kibble diet. Twenty beagles (BW = 10.25 ± 0.82 kg; age = 3.85 ± 1.84 yr) were used in a completely randomized design. Test diets included: 1) chicken and brown rice recipe [feed-grade; extruded; blue buffalo (BB)]; and 2) chicken and white rice [human-grade; mildly cooked; Just Food for Dogs (JFFD)]. The study consisted of a 4-week baseline when all dogs ate BB, and a 12-week treatment phase when dogs were randomized to either diet (n = 10/group). After the baseline and treatment phases, fresh fecal samples were scored and collected for pH, dry matter (DM), and microbiome analysis; blood samples were collected for gene expression analysis; hair samples were microscopically imaged; and skin was analyzed for delayed-type hypersensitivity (DTH), sebum concentration, hydration status, and transepidermal water loss (TEWL). Data were analyzed as a change from baseline (CFB) using the Mixed Models procedure of SAS (version 9.4). At baseline, fecal pH was higher (P < 0.05) and hair surface score, superoxide dismutase (SOD) expression, and tumor necrosis factor-α (TNF-α) expression was lower (P < 0.05) in dogs allotted to JFFD. The decrease in CFB fecal pH and DM was greater (P < 0.05) in dogs fed JFFD, but fecal scores were not different. The increase in CFB hair surface score was higher (P < 0.05) in dogs fed JFFD. The decrease in CFB TEWL (back region) was greater (P < 0.05) in dogs fed JFFD, but TEWL (inguinal and ear regions), hydration status, and sebum concentrations in all regions were not different. Hair cortex scores and DTH responses were not affected by diet. The increase in CFB gene expression of SOD, COX-2, and TNF-α was greater (P < 0.05) in dogs fed JFFD. PCoA plots based on Bray-Curtis distances of bacterial genera and species showed small shifts over time in dogs fed BB, but dramatic shifts in those fed JFFD. JFFD increased (adj. P < 0.05) relative abundances of 4 bacterial genera, 11 bacterial species, 68 KEGG pathways, and 167 MetaCyc pathways, and decreased (adj. P < 0.05) 16 genera, 25 species, 98 KEGG pathways, and 87 MetaCyc pathways. In conclusion, the JFFD diet dramatically shifted the fecal microbiome but had minor effects on skin and coat measures and gene expression.


This study tested the effects of a mildly cooked human-grade diet and a feed-grade extruded kibble diet on the fecal microbiome, skin and coat health measures, and expression of genes related to inflammation and oxidative stress in healthy adult dogs. During a 4-week baseline, 20 beagles consumed the kibble diet. After baseline, 10 dogs continued to consume that diet, while 10 dogs consumed the mildly cooked diet for 12 weeks. After baseline and treatment phases, fresh fecal, blood, and hair samples were collected and skin was analyzed. The mildly cooked diet led to lower fecal pH and dry matter percentage, but fecal scores were not affected. The mildly cooked diet dramatically altered the fecal microbiome, shifting the relative abundances of over 30 bacterial species and 165 bacterial metabolic pathways. Measures of skin sebum content and hydration status were not different between groups, but skin water loss was lower in dogs consuming the mildly cooked diet. Baseline and post-treatment gene expression and hair surface scores were noted, but hair cortex and delayed-type hypersensitivity testing were not altered by diet. Our results demonstrate that mildly cooked diets dramatically change the fecal microbiome, but may not impact skin and coat in healthy adult dogs over a short time period.


Asunto(s)
Digestión , Microbiota , Alimentación Animal/análisis , Animales , Bacterias , Ciclooxigenasa 2/farmacología , Dieta/veterinaria , Perros , Heces/microbiología , Expresión Génica , Humanos , Superóxido Dismutasa , Factor de Necrosis Tumoral alfa , Agua
6.
Open Forum Infect Dis ; 9(7): ofac192, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35791353

RESUMEN

Background: The global effort to vaccinate people against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during an ongoing pandemic has raised questions about how vaccine breakthrough infections compare with infections in immunologically naive individuals and the potential for vaccinated individuals to transmit the virus. Methods: We examined viral dynamics and infectious virus shedding through daily longitudinal sampling in 23 adults infected with SARS-CoV-2 at varying stages of vaccination, including 6 fully vaccinated individuals. Results: The durations of both infectious virus shedding and symptoms were significantly reduced in vaccinated individuals compared with unvaccinated individuals. We also observed that breakthrough infections are associated with strong tissue compartmentalization and are only detectable in saliva in some cases. Conclusions: Vaccination shortens the duration of time of high transmission potential, minimizes symptom duration, and may restrict tissue dissemination.

7.
Nat Microbiol ; 7(5): 640-652, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35484231

RESUMEN

The dynamics of SARS-CoV-2 replication and shedding in humans remain poorly understood. We captured the dynamics of infectious virus and viral RNA shedding during acute infection through daily longitudinal sampling of 60 individuals for up to 14 days. By fitting mechanistic models, we directly estimated viral expansion and clearance rates and overall infectiousness for each individual. Significant person-to-person variation in infectious virus shedding suggests that individual-level heterogeneity in viral dynamics contributes to 'superspreading'. Viral genome loads often peaked days earlier in saliva than in nasal swabs, indicating strong tissue compartmentalization and suggesting that saliva may serve as a superior sampling site for early detection of infection. Viral loads and clearance kinetics of Alpha (B.1.1.7) and previously circulating non-variant-of-concern viruses were mostly indistinguishable, indicating that the enhanced transmissibility of this variant cannot be explained simply by higher viral loads or delayed clearance. These results provide a high-resolution portrait of SARS-CoV-2 infection dynamics and implicate individual-level heterogeneity in infectiousness in superspreading.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Carga Viral , Esparcimiento de Virus
8.
Microbiol Resour Announc ; 11(4): e0117621, 2022 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-35254127

RESUMEN

We report here the complete genome sequences of three Staphylococcus haemolyticus strains isolated from a mouse fibrotic lung tissue and exhibiting proapoptotic activity on human lung alveolar epithelial cells. The genomes were obtained from a combination of Illumina MiSeq and Oxford Nanopore MinION sequencing.

9.
Curr Dev Nutr ; 6(3): nzac019, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35295713

RESUMEN

Background: Infants have low stores of vitamin K at birth. Dietary intake of phylloquinone (PK) differs dramatically by infant feeding practice, but the contribution of microbially produced vitamin K (menaquinones) to infant vitamin K status is not well understood. Objectives: The objective of this study was to investigate determinants of infant fecal vitamin K profiles in mother-infant dyads at 6 wk postpartum. Methods: Fecal and breast milk samples were collected from a subsample of breastfeeding (n = 23) or formula-feeding (n = 23) mother and infant dyads, delivered vaginally (n = 26) or by cesarean section (CS) (n = 20) in the Synergistic Theory and Research on Nutrition and Growth (STRONG) Kids 2 cohort. Vitamin K concentrations in breast milk and feces were analyzed by LC/MS and/or HPLC. Fecal bacterial metagenomes were analyzed to derive taxonomy and vitamin K biosynthetic genes. Multivariate linear modeling was used to assess effects of delivery and feeding modes on infant fecal vitamin K. Results: Breast milk contained 1.3 ± 0.2 ng/mL PK, and formula was reported to contain 52 ng/mL PK. Fecal PK was 38-times higher (P < 0.001) in formula-fed than breastfed infants. Infant fecal menaquinones (MKn) MK6, MK7, MK12, and MK13 were higher (P < 0.001) in formula-fed than breastfed infants, whereas MK8 predominated in breastfed and was 5-times higher than formula-fed infants. Total MKn were greater (P < 0.001) in vaginally delivered than CS infants. Relative abundances of 33 bacterial species were affected by feeding mode, 2 by delivery mode, and 4 by both (P < 0.05). Bacterial gene content of 5/12 vitamin K biosynthetic genes were greater (P < 0.05) in breastfed compared with formula-fed infants, and 1 differed by delivery mode. Conclusions: Feeding practice and delivery mode influence bacterial vitamin K production in the infant gut. High concentrations of unmetabolized PK in feces of formula-fed infants suggests formula PK content exceeds the absorptive capacity of the infant gut.

10.
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
11.
Front Cell Infect Microbiol ; 11: 794529, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34970511

RESUMEN

The Candida albicans agglutinin-like sequence (ALS) family is studied because of its contribution to cell adhesion, fungal colonization, and polymicrobial biofilm formation. The goal of this work was to derive an accurate census and sequence for ALS genes in pathogenic yeasts and other closely related species, while probing the boundaries of the ALS family within the Order Saccharomycetales. Bioinformatic methods were combined with laboratory experimentation to characterize 47 novel ALS loci from 8 fungal species. AlphaFold predictions suggested the presence of a conserved N-terminal adhesive domain (NT-Als) structure in all Als proteins reported to date, as well as in S. cerevisiae alpha-agglutinin (Sag1). Lodderomyces elongisporus, Meyerozyma guilliermondii, and Scheffersomyces stipitis were notable because each species had genes with C. albicans ALS features, as well as at least one that encoded a Sag1-like protein. Detection of recombination events between the ALS family and gene families encoding other cell-surface proteins such as Iff/Hyr and Flo suggest widespread domain swapping with the potential to create cell-surface diversity among yeast species. Results from the analysis also revealed subtelomeric ALS genes, ALS pseudogenes, and the potential for yeast species to secrete their own soluble adhesion inhibitors. Information presented here supports the inclusion of SAG1 in the ALS family and yields many experimental hypotheses to pursue to further reveal the nature of the ALS family.


Asunto(s)
Aglutininas , Saccharomycetales , Aglutininas/genética , Candida albicans , Proteínas Fúngicas/genética , Genómica , Humanos , Saccharomyces cerevisiae
12.
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
13.
F1000Res ; 102021.
Artículo en Inglés | MEDLINE | ID: mdl-34721839

RESUMEN

The 22nd annual Bioinformatics Open Source Conference (BOSC 2021, open-bio.org/events/bosc-2021/) was held online as a track of the 2021 Intelligent Systems for Molecular Biology / European Conference on Computational Biology (ISMB/ECCB) conference. Launched in 2000 and held every year since, BOSC is the premier meeting covering topics related to open source software and open science in bioinformatics. In 2020, BOSC partnered with the Galaxy Community Conference to form the Bioinformatics Community Conference (BCC2020); that was the first BOSC to be held online. This year, BOSC returned to its roots as part of ISMB/ECCB 2021. As in 2020, the Covid-19 pandemic made it impossible to hold the conference in person, so ISMB/ECCB 2021 took place as an online meeting attended by over 2000 people from 79 countries. Nearly 200 people participated in BOSC sessions, which included 27 talks reviewed and selected from submitted abstracts, and three invited keynote talks representing a range of global perspectives on the role of open science and open source in driving research and inclusivity in the biosciences, one of which was presented in French with English subtitles.


Asunto(s)
Biología Computacional , Humanos , Pandemias , Programas Informáticos
14.
medRxiv ; 2021 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-34494028

RESUMEN

The global effort to vaccinate people against SARS-CoV-2 in the midst of an ongoing pandemic has raised questions about the nature of vaccine breakthrough infections and the potential for vaccinated individuals to transmit the virus. These questions have become even more urgent as new variants of concern with enhanced transmissibility, such as Delta, continue to emerge. To shed light on how vaccine breakthrough infections compare with infections in immunologically naive individuals, we examined viral dynamics and infectious virus shedding through daily longitudinal sampling in a small cohort of adults infected with SARS-CoV-2 at varying stages of vaccination. The durations of both infectious virus shedding and symptoms were significantly reduced in vaccinated individuals compared with unvaccinated individuals. We also observed that breakthrough infections are associated with strong tissue compartmentalization and are only detectable in saliva in some cases. These data indicate that vaccination shortens the duration of time of high transmission potential, minimizes symptom duration, and may restrict tissue dissemination.

15.
Toxics ; 9(9)2021 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-34564366

RESUMEN

Di-2-ethylhexyl phthalate (DEHP) is a plasticizer commonly found in polyvinyl chloride, medical equipment, and food packaging. DEHP has been shown to target the reproductive system and alter the gut microbiome in humans and experimental animals. However, very little is known about the impact of DEHP-induced microbiome changes and its effects during pregnancy. Thus, the objective of this study was to investigate the effects of DEHP exposure during pregnancy on the cecal microbiome and pregnancy outcomes. Specifically, this study tested the hypothesis that subacute exposure to DEHP during pregnancy alters the cecal microbiome in pregnant mice, leading to changes in birth outcomes. To test this hypothesis, pregnant dams were orally exposed to corn oil vehicle or 20 µg/kg/day DEHP for 10 days and euthanized 21 days after their last dose. Cecal contents were collected for 16S Illumina and shotgun metagenomic sequencing. Fertility studies were also conducted to examine whether DEHP exposure impacted birth outcomes. Subacute exposure to environmentally relevant doses of DEHP in pregnant dams significantly increased alpha diversity and significantly altered beta diversity. Furthermore, DEHP exposure during pregnancy significantly increased the relative abundance of Bacteroidetes and decreased the relative abundance of Firmicutes and Deferribacteres compared with controls. The affected taxonomic families included Deferribacteraceae, Lachnospiraceae, and Mucisprillum. In addition to changes in the gut microbiota, DEHP exposure significantly altered 14 functional pathways compared with the control. Finally, DEHP exposure did not significantly impact the fertility and birth outcomes compared with the control. Collectively, these data indicate that DEHP exposure during pregnancy shifts the cecal microbiome, but the shifts do not impact fertility and birth outcomes.

16.
medRxiv ; 2021 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-34282424

RESUMEN

The dynamics of SARS-CoV-2 replication and shedding in humans remain poorly understood. We captured the dynamics of infectious virus and viral RNA shedding during acute infection through daily longitudinal sampling of 60 individuals for up to 14 days. By fitting mechanistic models, we directly estimate viral reproduction and clearance rates, and overall infectiousness for each individual. Significant person-to-person variation in infectious virus shedding suggests that individual-level heterogeneity in viral dynamics contributes to superspreading. Viral genome load often peaked days earlier in saliva than in nasal swabs, indicating strong compartmentalization and suggesting that saliva may serve as a superior sampling site for early detection of infection. Viral loads and clearance kinetics of B.1.1.7 and non-B.1.1.7 viruses in nasal swabs were indistinguishable, however B.1.1.7 exhibited a significantly slower pre-peak growth rate in saliva. These results provide a high-resolution portrait of SARS-CoV-2 infection dynamics and implicate individual-level heterogeneity in infectiousness in superspreading.

17.
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
18.
mBio ; 12(2)2021 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-33658330

RESUMEN

Fibrobacter succinogenes, Ruminococcus albus, and Ruminococcus flavefaciens are the three predominant cellulolytic bacterial species found in the rumen. In vitro studies have shown that these species compete for adherence to, and growth upon, cellulosic biomass. Yet their molecular interactions in vivo have not heretofore been examined. Gnotobiotically raised lambs harboring a 17-h-old immature microbiota devoid of culturable cellulolytic bacteria and methanogens were inoculated first with F. succinogenes S85 and Methanobrevibacter sp. strain 87.7, and 5 months later, the lambs were inoculated with R. albus 8 and R. flavefaciens FD-1. Longitudinal samples were collected and profiled for population dynamics, gene expression, fibrolytic enzyme activity, in sacco fibrolysis, and metabolite profiling. Quantitative PCR, metagenome and metatranscriptome data show that F. succinogenes establishes at high levels initially but is gradually outcompeted following the introduction of the ruminococci. This shift resulted in an increase in carboxymethyl cellulase (CMCase) and xylanase activities but not in greater fibrolysis, suggesting that F. succinogenes and ruminococci deploy different but equally effective means to degrade plant cell walls. Expression profiles showed that F. succinogenes relied upon outer membrane vesicles and a diverse repertoire of CAZymes, while R. albus and R. flavefaciens preferred type IV pili and either CBM37-harboring or cellulosomal carbohydrate-active enzymes (CAZymes), respectively. The changes in cellulolytics also affected the rumen metabolome, including an increase in acetate and butyrate at the expense of propionate. In conclusion, this study provides the first demonstration of in vivo competition between the three predominant cellulolytic bacteria and provides insight on the influence of these ecological interactions on rumen fibrolytic function and metabolomic response.IMPORTANCE Ruminant animals, including cattle and sheep, depend on their rumen microbiota to digest plant biomass and convert it into absorbable energy. Considering that the extent of meat and milk production depends on the efficiency of the microbiota to deconstruct plant cell walls, the functionality of predominant rumen cellulolytic bacteria, Fibrobacter succinogenes, Ruminococcus albus, and Ruminococcus flavefaciens, has been extensively studied in vitro to obtain a better knowledge of how they operate to hydrolyze polysaccharides and ultimately find ways to enhance animal production. This study provides the first evidence of in vivo competitions between F. succinogenes and the two Ruminococcus species. It shows that a simple disequilibrium within the cellulolytic community has repercussions on the rumen metabolome and fermentation end products. This finding will have to be considered in the future when determining strategies aiming at directing rumen fermentations for animal production.


Asunto(s)
Fibrobacter/genética , Perfilación de la Expresión Génica , Metagenoma , Interacciones Microbianas/genética , Rumen/microbiología , Ruminococcus/genética , Factores de Edad , Animales , Femenino , Fibrobacter/fisiología , Vida Libre de Gérmenes , Masculino , Metagenómica , ARN Ribosómico 16S/genética , Ruminococcus/fisiología , Ovinos/microbiología
19.
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
20.
F1000Res ; 92020.
Artículo en Inglés | MEDLINE | ID: mdl-32983415

RESUMEN

Launched in 2000 and held every year since, the Bioinformatics Open Source Conference (BOSC) is a volunteer-run meeting coordinated by the Open Bioinformatics Foundation (OBF) that covers open source software development and open science in bioinformatics. Most years, BOSC has been part of the Intelligent Systems for Molecular Biology (ISMB) conference, but in 2018, and again in 2020, BOSC partnered with the Galaxy Community Conference (GCC). This year's combined BOSC + GCC conference was called the Bioinformatics Community Conference (BCC2020, bcc2020.github.io). Originally slated to take place in Toronto, Canada, BCC2020 was moved online due to COVID-19. The meeting started with a wide array of training sessions; continued with a main program of keynote presentations, talks, posters, Birds of a Feather, and more; and ended with four days of collaboration (CoFest). Efforts to make the meeting accessible and inclusive included very low registration fees, talks presented twice a day, and closed captioning for all videos. More than 800 people from 61 countries registered for at least one part of the meeting, which was held mostly in the Remo.co video-conferencing platform.


Asunto(s)
Biología Computacional , Congresos como Asunto , Canadá , Humanos
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