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1.
Database (Oxford) ; 20242024 May 07.
Article in English | MEDLINE | ID: mdl-38713862

ABSTRACT

Germline and somatic mutations can give rise to proteins with altered activity, including both gain and loss-of-function. The effects of these variants can be captured in disease-specific reactions and pathways that highlight the resulting changes to normal biology. A disease reaction is defined as an aberrant reaction in which a variant protein participates. A disease pathway is defined as a pathway that contains a disease reaction. Annotation of disease variants as participants of disease reactions and disease pathways can provide a standardized overview of molecular phenotypes of pathogenic variants that is amenable to computational mining and mathematical modeling. Reactome (https://reactome.org/), an open source, manually curated, peer-reviewed database of human biological pathways, in addition to providing annotations for >11 000 unique human proteins in the context of ∼15 000 wild-type reactions within more than 2000 wild-type pathways, also provides annotations for >4000 disease variants of close to 400 genes as participants of ∼800 disease reactions in the context of ∼400 disease pathways. Functional annotation of disease variants proceeds from normal gene functions, described in wild-type reactions and pathways, through disease variants whose divergence from normal molecular behaviors has been experimentally verified, to extrapolation from molecular phenotypes of characterized variants to variants of unknown significance using criteria of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Reactome's data model enables mapping of disease variant datasets to specific disease reactions within disease pathways, providing a platform to infer pathway output impacts of numerous human disease variants and model organism orthologs, complementing computational predictions of variant pathogenicity. Database URL: https://reactome.org/.


Subject(s)
Molecular Sequence Annotation , Phenotype , Humans , Databases, Genetic , Disease/genetics
2.
Nucleic Acids Res ; 52(D1): D672-D678, 2024 Jan 05.
Article in English | MEDLINE | ID: mdl-37941124

ABSTRACT

The Reactome Knowledgebase (https://reactome.org), an Elixir and GCBR core biological data resource, provides manually curated molecular details of a broad range of normal and disease-related biological processes. Processes are annotated as an ordered network of molecular transformations in a single consistent data model. Reactome thus functions both as a digital archive of manually curated human biological processes and as a tool for discovering functional relationships in data such as gene expression profiles or somatic mutation catalogs from tumor cells. Here we review progress towards annotation of the entire human proteome, targeted annotation of disease-causing genetic variants of proteins and of small-molecule drugs in a pathway context, and towards supporting explicit annotation of cell- and tissue-specific pathways. Finally, we briefly discuss issues involved in making Reactome more fully interoperable with other related resources such as the Gene Ontology and maintaining the resulting community resource network.


Subject(s)
Knowledge Bases , Metabolic Networks and Pathways , Signal Transduction , Humans , Metabolic Networks and Pathways/genetics , Proteome/genetics
3.
bioRxiv ; 2023 Nov 08.
Article in English | MEDLINE | ID: mdl-37986970

ABSTRACT

Appreciating the rapid advancement and ubiquity of generative AI, particularly ChatGPT, a chatbot using large language models like GPT, we endeavour to explore the potential application of ChatGPT in the data collection and annotation stages within the Reactome curation process. This exploration aimed to create an automated or semi-automated framework to mitigate the extensive manual effort traditionally required for gathering and annotating information pertaining to biological pathways, adopting a Reactome "reaction-centric" approach. In this pilot study, we used ChatGPT/GPT4 to address gaps in the pathway annotation and enrichment in parallel with the conventional manual curation process. This approach facilitated a comparative analysis, where we assessed the outputs generated by ChatGPT against manually extracted information. The primary objective of this comparison was to ascertain the efficiency of integrating ChatGPT or other large language models into the Reactome curation workflow and helping plan our annotation pipeline, ultimately improving our protein-to-pathway association in a reliable and automated or semi-automated way. In the process, we identified some promising capabilities and inherent challenges associated with the utilisation of ChatGPT/GPT4 in general and also specifically in the context of Reactome curation processes. We describe approaches and tools for refining the output given by ChatGPT/GPT4 that aid in generating more accurate and detailed output.

4.
bioRxiv ; 2023 Oct 21.
Article in English | MEDLINE | ID: mdl-37904913

ABSTRACT

Disease variant annotation in the context of biological reactions and pathways can provide a standardized overview of molecular phenotypes of pathogenic mutations that is amenable to computational mining and mathematical modeling. Reactome, an open source, manually curated, peer-reviewed database of human biological pathways, provides annotations for over 4000 disease variants of close to 400 genes in the context of ∼800 disease reactions constituting ∼400 disease pathways. Functional annotation of disease variants proceeds from normal gene functions, through disease variants whose divergence from normal molecular behaviors has been experimentally verified, to extrapolation from molecular phenotypes of characterized variants to variants of unknown significance using criteria of the American College of Medical Genetics and Genomics (ACMG). Reactome's pathway-based, reaction-specific disease variant dataset and data model provide a platform to infer pathway output impacts of numerous human disease variants and model organism orthologs, complementing computational predictions of variant pathogenicity.

5.
Curr Protoc ; 3(4): e722, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37053306

ABSTRACT

Pathway databases provide descriptions of the roles of proteins, nucleic acids, lipids, carbohydrates, and other molecular entities within their biological cellular contexts. Pathway-centric views of these roles may allow for the discovery of unexpected functional relationships in data such as gene expression profiles and somatic mutation catalogues from tumor cells. For this reason, there is a high demand for high-quality pathway databases and their associated tools. The Reactome project (a collaboration between the Ontario Institute for Cancer Research, New York University Langone Health, the European Bioinformatics Institute, and Oregon Health & Science University) is one such pathway database. Reactome collects detailed information on biological pathways and processes in humans from the primary literature. Reactome content is manually curated, expert-authored, and peer-reviewed and spans the gamut from simple intermediate metabolism to signaling pathways and complex cellular events. This information is supplemented with likely orthologous molecular reactions in mouse, rat, zebrafish, worm, and other model organisms. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Browsing a Reactome pathway Basic Protocol 2: Exploring Reactome annotations of disease and drugs Basic Protocol 3: Finding the pathways involving a gene or protein Alternate Protocol 1: Finding the pathways involving a gene or protein using UniProtKB (SwissProt), Ensembl, or Entrez gene identifier Alternate Protocol 2: Using advanced search Basic Protocol 4: Using the Reactome pathway analysis tool to identify statistically overrepresented pathways Basic Protocol 5: Using the Reactome pathway analysis tool to overlay expression data onto Reactome pathway diagrams Basic Protocol 6: Comparing inferred model organism and human pathways using the Species Comparison tool Basic Protocol 7: Comparing tissue-specific expression using the Tissue Distribution tool.


Subject(s)
Metabolic Networks and Pathways , Zebrafish , Humans , Animals , Mice , Rats , Zebrafish/metabolism , Databases, Protein , Proteins/metabolism , Signal Transduction
6.
Int Immunopharmacol ; 103: 108412, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34942461

ABSTRACT

Levocetirizine, a third-generation antihistamine, and montelukast, a leukotriene receptor antagonist, exhibit remarkable synergistic anti-inflammatory activity across a spectrum of signaling proteins, cell adhesion molecules, and leukocytes. By targeting cellular protein activity, they are uniquely positioned to treat the symptoms of COVID-19. Clinical data to date with an associated six-month follow-up, suggests the combination therapy may prevent the progression of the disease from mild to moderate to severe, as well as prevent/treat many of the aspects of 'Long COVID,' thereby cost effectively reducing both morbidity and mortality. To investigate patient outcomes, 53 consecutive COVID-19 test (+) cases (ages 3-90) from a well-established, single-center practice in Boston, Massachusetts, between March - November 2020, were treated with levocetirizine and montelukast in addition to then existing protocols [2]. The data set was retrospectively reviewed. Thirty-four cases were considered mild (64%), 17 moderate (32%), and 2 (4%) severe. Several patients presented with significant comorbidities (obesity: n = 22, 41%; diabetes: n = 10, 19%; hypertension: n = 24, 45%). Among the cohort there were no exclusions, no intubations, and no deaths. The pilot study in Massachusetts encompassed the first COVID-19 wave which peaked on April 23, 2020 as well as the ascending portion of the second wave in the fall. During this period the average weekly COVID-19 case mortality rate (confirmed deaths/confirmed cases) varied considerably between 1 and 7.5% [37]. FDA has approved a multicenter, randomized, placebo-controlled, Phase 2 clinical trial design, replete with electronic diaries and laboratory metrics to explore scientific questions not addressed herein.


Subject(s)
Acetates/therapeutic use , COVID-19 Drug Treatment , Cetirizine/therapeutic use , Cyclopropanes/therapeutic use , Histamine H1 Antagonists, Non-Sedating/therapeutic use , Leukotriene Antagonists/therapeutic use , Quinolines/therapeutic use , SARS-CoV-2/drug effects , Sulfides/therapeutic use , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Retrospective Studies , Treatment Outcome , Young Adult
7.
Nucleic Acids Res ; 50(D1): D687-D692, 2022 01 07.
Article in English | MEDLINE | ID: mdl-34788843

ABSTRACT

The Reactome Knowledgebase (https://reactome.org), an Elixir core resource, provides manually curated molecular details across a broad range of physiological and pathological biological processes in humans, including both hereditary and acquired disease processes. The processes are annotated as an ordered network of molecular transformations in a single consistent data model. Reactome thus functions both as a digital archive of manually curated human biological processes and as a tool for discovering functional relationships in data such as gene expression profiles or somatic mutation catalogs from tumor cells. Recent curation work has expanded our annotations of normal and disease-associated signaling processes and of the drugs that target them, in particular infections caused by the SARS-CoV-1 and SARS-CoV-2 coronaviruses and the host response to infection. New tools support better simultaneous analysis of high-throughput data from multiple sources and the placement of understudied ('dark') proteins from analyzed datasets in the context of Reactome's manually curated pathways.


Subject(s)
Antiviral Agents/pharmacology , Knowledge Bases , Proteins/metabolism , COVID-19/metabolism , Data Curation , Genome, Human , Host-Pathogen Interactions , Humans , Proteins/genetics , Signal Transduction , Software
8.
Front Immunol ; 12: 766112, 2021.
Article in English | MEDLINE | ID: mdl-34938290

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health concern. The development of vaccines with high immunogenicity and safety is crucial for controlling the global COVID-19 pandemic and preventing further illness and fatalities. Here, we report the development of a SARS-CoV-2 vaccine candidate, Nanocovax, based on recombinant protein production of the extracellular (soluble) portion of the spike (S) protein of SARS-CoV-2. The results showed that Nanocovax induced high levels of S protein-specific IgG and neutralizing antibodies in three animal models: BALB/c mouse, Syrian hamster, and a non-human primate (Macaca leonina). In addition, a viral challenge study using the hamster model showed that Nanocovax protected the upper respiratory tract from SARS-CoV-2 infection. Nanocovax did not induce any adverse effects in mice (Mus musculus var. albino) and rats (Rattus norvegicus). These preclinical results indicate that Nanocovax is safe and effective.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19 Vaccines/toxicity , COVID-19/prevention & control , Immunogenicity, Vaccine/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Cricetinae , Macaca , Mice , Rats , SARS-CoV-2 , Vaccines, Synthetic/immunology , Vaccines, Synthetic/toxicity
9.
Nucleic Acids Res ; 48(D1): D498-D503, 2020 01 08.
Article in English | MEDLINE | ID: mdl-31691815

ABSTRACT

The Reactome Knowledgebase (https://reactome.org) provides molecular details of signal transduction, transport, DNA replication, metabolism and other cellular processes as an ordered network of molecular transformations in a single consistent data model, an extended version of a classic metabolic map. Reactome functions both as an archive of biological processes and as a tool for discovering functional relationships in data such as gene expression profiles or somatic mutation catalogs from tumor cells. To extend our ability to annotate human disease processes, we have implemented a new drug class and have used it initially to annotate drugs relevant to cardiovascular disease. Our annotation model depends on external domain experts to identify new areas for annotation and to review new content. New web pages facilitate recruitment of community experts and allow those who have contributed to Reactome to identify their contributions and link them to their ORCID records. To improve visualization of our content, we have implemented a new tool to automatically lay out the components of individual reactions with multiple options for downloading the reaction diagrams and associated data, and a new display of our event hierarchy that will facilitate visual interpretation of pathway analysis results.


Subject(s)
Databases, Chemical , Databases, Pharmaceutical , Knowledge Bases , Software , Genome, Human , Humans , Metabolic Networks and Pathways , Protein Interaction Maps , Signal Transduction
10.
Food Funct ; 10(2): 951-963, 2019 Feb 20.
Article in English | MEDLINE | ID: mdl-30702109

ABSTRACT

Apple pomace, a by-product of juice production, is a high-fibre, high-polyphenol functional food ingredient. Extrusion (barrel moisture 15%, 20% or 30%) of apple pomace, followed by drying, allows it to be supplied in a convenient form. Extrusion caused degradation of the apple pomace cell wall structure. Water solubility was significantly increased by extrusion but oil holding capacity was reduced. Total extractable polyphenols, measured as gallic acid equivalents, were reduced by extrusion (barrel moisture 30%) but were not affected by extrusion at lower barrel moisture contents (15% or 20%). However, individual sub-groups of extractable flavanols, flavonols, phenolic acids and dihydrochalcones were increased by extrusion. There was little effect of extrusion on the release of total polyphenols from the matrix into the supernatant, as measured by total extractable polyphenols (measured as gallic acid equivalents) released during in vitro digestion. There was a marked increase in total flavanols, phenolic acids and dihydrochalones released into the supernatant during the gastric phase but changes in flavonoids were less obvious. The changes in the bioaccessibility of individual polyphenols released during intestinal digestion were dependent on the type of polyphenol and extrusion conditions. The antioxidant activity, as measured using oxygen radical absorbance capacity (ORAC) of the bioaccessible nutrients released upon in vitro intestinal digestion, was significantly enhanced by extrusion (from 78.2 to 400-500 µmol Trolox equivalents per mL at the ileal phase). The increased ORAC may be attributed in part to the increased release of individual polyphenols.


Subject(s)
Antioxidants/pharmacology , Food Handling , Fruit/chemistry , Malus/chemistry , Antioxidants/chemistry , Hydrogen-Ion Concentration , Polyphenols
11.
Nucleic Acids Res ; 46(D1): D649-D655, 2018 01 04.
Article in English | MEDLINE | ID: mdl-29145629

ABSTRACT

The Reactome Knowledgebase (https://reactome.org) provides molecular details of signal transduction, transport, DNA replication, metabolism, and other cellular processes as an ordered network of molecular transformations-an extended version of a classic metabolic map, in a single consistent data model. Reactome functions both as an archive of biological processes and as a tool for discovering unexpected functional relationships in data such as gene expression profiles or somatic mutation catalogues from tumor cells. To support the continued brisk growth in the size and complexity of Reactome, we have implemented a graph database, improved performance of data analysis tools, and designed new data structures and strategies to boost diagram viewer performance. To make our website more accessible to human users, we have improved pathway display and navigation by implementing interactive Enhanced High Level Diagrams (EHLDs) with an associated icon library, and subpathway highlighting and zooming, in a simplified and reorganized web site with adaptive design. To encourage re-use of our content, we have enabled export of pathway diagrams as 'PowerPoint' files.


Subject(s)
Knowledge Bases , Metabolic Networks and Pathways , Computer Graphics , Databases, Chemical , Databases, Protein , Humans , Internet , Molecular Sequence Annotation , Signal Transduction , User-Computer Interface
12.
Bioinformatics ; 33(21): 3461-3467, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-29077811

ABSTRACT

MOTIVATION: Reactome is a free, open-source, open-data, curated and peer-reviewed knowledge base of biomolecular pathways. Pathways are arranged in a hierarchical structure that largely corresponds to the GO biological process hierarchy, allowing the user to navigate from high level concepts like immune system to detailed pathway diagrams showing biomolecular events like membrane transport or phosphorylation. Here, we present new developments in the Reactome visualization system that facilitate navigation through the pathway hierarchy and enable efficient reuse of Reactome visualizations for users' own research presentations and publications. RESULTS: For the higher levels of the hierarchy, Reactome now provides scalable, interactive textbook-style diagrams in SVG format, which are also freely downloadable and editable. Repeated diagram elements like 'mitochondrion' or 'receptor' are available as a library of graphic elements. Detailed lower-level diagrams are now downloadable in editable PPTX format as sets of interconnected objects. AVAILABILITY AND IMPLEMENTATION: http://reactome.org. CONTACT: fabregat@ebi.ac.uk or hhe@ebi.ac.uk.


Subject(s)
Biological Phenomena , Knowledge Bases , User-Computer Interface , Computer Graphics , Gene Ontology , Internet , Libraries , Signal Transduction
13.
Nucleic Acids Res ; 44(D1): D481-7, 2016 Jan 04.
Article in English | MEDLINE | ID: mdl-26656494

ABSTRACT

The Reactome Knowledgebase (www.reactome.org) provides molecular details of signal transduction, transport, DNA replication, metabolism and other cellular processes as an ordered network of molecular transformations-an extended version of a classic metabolic map, in a single consistent data model. Reactome functions both as an archive of biological processes and as a tool for discovering unexpected functional relationships in data such as gene expression pattern surveys or somatic mutation catalogues from tumour cells. Over the last two years we redeveloped major components of the Reactome web interface to improve usability, responsiveness and data visualization. A new pathway diagram viewer provides a faster, clearer interface and smooth zooming from the entire reaction network to the details of individual reactions. Tool performance for analysis of user datasets has been substantially improved, now generating detailed results for genome-wide expression datasets within seconds. The analysis module can now be accessed through a RESTFul interface, facilitating its inclusion in third party applications. A new overview module allows the visualization of analysis results on a genome-wide Reactome pathway hierarchy using a single screen page. The search interface now provides auto-completion as well as a faceted search to narrow result lists efficiently.


Subject(s)
Databases, Chemical , Metabolic Networks and Pathways , Gene Expression , Humans , Knowledge Bases , Proteins/metabolism , Signal Transduction , Software
14.
Nucleic Acids Res ; 42(Database issue): D472-7, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24243840

ABSTRACT

Reactome (http://www.reactome.org) is a manually curated open-source open-data resource of human pathways and reactions. The current version 46 describes 7088 human proteins (34% of the predicted human proteome), participating in 6744 reactions based on data extracted from 15 107 research publications with PubMed links. The Reactome Web site and analysis tool set have been completely redesigned to increase speed, flexibility and user friendliness. The data model has been extended to support annotation of disease processes due to infectious agents and to mutation.


Subject(s)
Databases, Protein , Proteins/metabolism , Disease , Humans , Internet , Knowledge Bases , Metabolic Networks and Pathways
15.
Nucleic Acids Res ; 39(Database issue): D691-7, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21067998

ABSTRACT

Reactome (http://www.reactome.org) is a collaboration among groups at the Ontario Institute for Cancer Research, Cold Spring Harbor Laboratory, New York University School of Medicine and The European Bioinformatics Institute, to develop an open source curated bioinformatics database of human pathways and reactions. Recently, we developed a new web site with improved tools for pathway browsing and data analysis. The Pathway Browser is an Systems Biology Graphical Notation (SBGN)-based visualization system that supports zooming, scrolling and event highlighting. It exploits PSIQUIC web services to overlay our curated pathways with molecular interaction data from the Reactome Functional Interaction Network and external interaction databases such as IntAct, BioGRID, ChEMBL, iRefIndex, MINT and STRING. Our Pathway and Expression Analysis tools enable ID mapping, pathway assignment and overrepresentation analysis of user-supplied data sets. To support pathway annotation and analysis in other species, we continue to make orthology-based inferences of pathways in non-human species, applying Ensembl Compara to identify orthologs of curated human proteins in each of 20 other species. The resulting inferred pathway sets can be browsed and analyzed with our Species Comparison tool. Collaborations are also underway to create manually curated data sets on the Reactome framework for chicken, Drosophila and rice.


Subject(s)
Databases, Factual , Models, Biological , Biological Phenomena , Computer Graphics , Databases, Genetic , Databases, Protein , Gene Expression Regulation , Humans , Internet , Metabolic Networks and Pathways , Signal Transduction
16.
Macromol Rapid Commun ; 31(3): 300-4, 2010 Feb 02.
Article in English | MEDLINE | ID: mdl-21590906

ABSTRACT

A close correllation between molecular-level interactions and macroscopic characteristics of polymer networks exists. The characteristics of the polymeric hydrogels assembled from ß-cyclodextrin (ß-CD) and adamantyl (AD) substituted poly(acrylate)s can be tailored through selective host-guest complexation between ß-CD and AD substituents and their tethers. Dominantly, steric effects and competitive intra- and intermolecular host-guest complexation are found to control poly(acrylate) isomeric inter-strand linkage in polymer network formation. This understanding of the factors involved in polymeric hydrogel formation points the way towards the construction of increasingly sophisticated biocompatible materials.

17.
Nucleic Acids Res ; 37(Database issue): D619-22, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18981052

ABSTRACT

Reactome (http://www.reactome.org) is an expert-authored, peer-reviewed knowledgebase of human reactions and pathways that functions as a data mining resource and electronic textbook. Its current release includes 2975 human proteins, 2907 reactions and 4455 literature citations. A new entity-level pathway viewer and improved search and data mining tools facilitate searching and visualizing pathway data and the analysis of user-supplied high-throughput data sets. Reactome has increased its utility to the model organism communities with improved orthology prediction methods allowing pathway inference for 22 species and through collaborations to create manually curated Reactome pathway datasets for species including Arabidopsis, Oryza sativa (rice), Drosophila and Gallus gallus (chicken). Reactome's data content and software can all be freely used and redistributed under open source terms.


Subject(s)
Databases, Protein , Physiological Phenomena , Proteins/metabolism , Animals , Humans , Metabolic Networks and Pathways , Models, Animal , Proteins/genetics , Proteins/physiology , Signal Transduction , Software , Systems Integration
18.
Anal Biochem ; 384(1): 27-33, 2009 Jan 01.
Article in English | MEDLINE | ID: mdl-18848516

ABSTRACT

In this article, we describe a simple, sensitive, accurate, and repeatable method for the measurement of phenol and p-cresol (4-methylphenol) in human urine and feces. We examined a number of parameters to identify an optimal extraction protocol. Purification of sample extracts was achieved by low-temperature vacuum microdistillation. Separation was achieved in approximately 15 min by high-performance liquid chromatography (HPLC) with quantification by fluorescence at 284/310 nm. Limits of detection for phenol were 2 ng/ml for urine and 20 ng/g for feces, and those for p-cresol were 10 ng/ml for urine and 100 ng/g for feces. For comparison, approximate mean values for urine are 3 microg/ml for phenol and 30 microg/ml for p-cresol, and those for feces are 1 microg/g for phenol and 50 microg/g for p-cresol. An experienced analyst can process 60 samples each day using this method.


Subject(s)
Chromatography, High Pressure Liquid/methods , Cresols/analysis , Feces/chemistry , Phenol/analysis , Cresols/urine , Humans , Phenol/urine , Reference Values
19.
Plant J ; 55(3): 514-25, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18410481

ABSTRACT

The interphase nucleus exists as a highly dynamic system, the physical properties of which have functional importance in gene regulation. Not only can gene expression be influenced by the local sequence context, but also by the architecture of the nucleus in three-dimensions (3D), and by the interactions between these levels via chromatin modifications. A challenging task is to resolve the complex interplay between sequence- and genome structure-based control mechanisms. Here, we created a collection of 277 Arabidopsis lines that allow the visual tracking of individual loci in living plants while comparing gene expression potential at these locations, via an identical reporter cassette. Our studies revealed regional gene silencing near a heterochromatin island, via DNA methylation, that is correlated with mobility constraint and nucleolar association. We also found an example of nucleolar association that does not correlate with gene suppression, suggesting that distinct mechanisms exist that can mediate interactions between chromatin and the nucleolus. These studies demonstrate the utility of this novel resource in unifying structural and functional studies towards a more comprehensive model of how global chromatin organization may coordinate gene expression over large scales.


Subject(s)
Arabidopsis/genetics , Chromatin/metabolism , DNA Transposable Elements , Genome, Plant , Transcription, Genetic , Arabidopsis/metabolism , Cell Nucleolus/metabolism , Chromatin/chemistry , Chromatin Assembly and Disassembly , Chromosome Mapping , Chromosomes, Plant , DNA Methylation , Gene Expression Regulation, Plant , Gene Silencing
20.
Plant Cell ; 17(9): 2486-506, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16055634

ABSTRACT

To identify genes involved in Arabidopsis thaliana petal and stamen organogenesis, we used a gene trap approach to examine the patterns of reporter expression at each stage of flower development of 1765 gene trap lines. In 80 lines, the reporter gene showed petal- and/or stamen-specific expression or lack of expression, or expression in distinct patterns within the petals and/or the stamens, including distinct suborgan domains of expression, such as tissue-specific lines marking epidermis and vasculature, as well as lines demarcating the proximodistal or abaxial/adaxial axes of the organs. Interestingly, reporter gene expression was typically restricted along the proximodistal axis of petals and stamens, indicating the importance of this developmental axis in patterning of gene expression domains in these organs. We identified novel domains of gene expression along the axis marking the midregion of the petals and apical and basal parts of the anthers. Most of the genes tagged in these 80 lines were identified, and their possible functions in petal and/or stamen differentiation are discussed. We also scored the floral phenotypes of the 1765 gene trap lines and recovered two mutants affecting previously uncharacterized genes. In addition to revealing common domains of gene expression, the gene trap lines reported here provide both useful markers and valuable starting points for reverse genetic analyses of the differentiation pathways in petal and stamen development.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Flowers , Gene Expression Regulation, Plant , Arabidopsis/anatomy & histology , Arabidopsis/genetics , Arabidopsis/growth & development , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Flowers/anatomy & histology , Flowers/physiology , Genes, Reporter , Morphogenesis , Phenotype
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