364 research outputs found

    The International Nucleotide Sequence Database Collaboration

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    Under the International Nucleotide Sequence Database Collaboration (INSDC; http://www.insdc.org), globally comprehensive public domain nucleotide sequence is captured, preserved and presented. The partners of this long-standing collaboration work closely together to provide data formats and conventions that enable consistent data submission to their databases and support regular data exchange around the globe. Clearly defined policy and governance in relation to free access to data and relationships with journal publishers have positioned INSDC databases as a key provider of the scientific record and a core foundation for the global bioinformatics data infrastructure. While growth in sequence data volumes comes no longer as a surprise to INSDC partners, the uptake of next-generation sequencing technology by mainstream science that we have witnessed in recent years brings a step-change to growth, necessarily making a clear mark on INSDC strategy. In this article, we introduce the INSDC, outline data growth patterns and comment on the challenges of increased growth

    GenBank

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    GenBank® is a comprehensive database that contains publicly available nucleotide sequences for more than 300 000 organisms named at the genus level or lower, obtained primarily through submissions from individual laboratories and batch submissions from large-scale sequencing projects, including whole genome shotgun (WGS) and environmental sampling projects. Most submissions are made using the web-based BankIt or standalone Sequin programs, and accession numbers are assigned by GenBank staff upon receipt. Daily data exchange with the European Molecular Biology Laboratory Nucleotide Sequence Database in Europe and the DNA Data Bank of Japan ensures worldwide coverage. GenBank is accessible through the NCBI Entrez retrieval system, which integrates data from the major DNA and protein sequence databases along with taxonomy, genome, mapping, protein structure and domain information, and the biomedical journal literature via PubMed. BLAST provides sequence similarity searches of GenBank and other sequence databases. Complete bi-monthly releases and daily updates of the GenBank database are available by FTP. To access GenBank and its related retrieval and analysis services, begin at the NCBI homepage: www.ncbi.nlm.nih.gov

    GenBank

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    GenBank® is a comprehensive database that contains publicly available nucleotide sequences for more than 250 000 formally described species. These sequences are obtained primarily through submissions from individual laboratories and batch submissions from large-scale sequencing projects, including whole-genome shotgun (WGS) and environmental sampling projects. Most submissions are made using the web-based BankIt or standalone Sequin programs, and accession numbers are assigned by GenBank staff upon receipt. Daily data exchange with the European Nucleotide Archive (ENA) and the DNA Data Bank of Japan (DDBJ) ensures worldwide coverage. GenBank is accessible through the NCBI Entrez retrieval system, which integrates data from the major DNA and protein sequence databases along with taxonomy, genome, mapping, protein structure and domain information, and the biomedical journal literature via PubMed. BLAST provides sequence similarity searches of GenBank and other sequence databases. Complete bimonthly releases and daily updates of the GenBank database are available by FTP. To access GenBank and its related retrieval and analysis services, begin at the NCBI home page: www.ncbi.nlm.nih.gov

    Transgenic Overexpression of Active Calcineurin in β-Cells Results in Decreased β-Cell Mass and Hyperglycemia

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    BACKGROUND:Glucose modulates beta-cell mass and function through an initial depolarization and Ca(2+) influx, which then triggers a number of growth regulating signaling pathways. One of the most important downstream effectors in Ca(2+) signaling is the calcium/Calmodulin activated serine threonine phosphatase, calcineurin. Recent evidence suggests that calcineurin/NFAT is essential for beta-cell proliferation, and that in its absence loss of beta-cells results in diabetes. We hypothesized that in contrast, activation of calcineurin might result in expansion of beta-cell mass and resistance to diabetes. METHODOLOGY/PRINCIPAL FINDINGS:To determine the role of activation of calcineurin signaling in the regulation of pancreatic beta-cell mass and proliferation, we created mice that expressed a constitutively active form of calcineurin under the insulin gene promoter (caCn(RIP)). To our surprise, these mice exhibited glucose intolerance. In vitro studies demonstrated that while the second phase of Insulin secretion is enhanced, the overall insulin secretory response was conserved. Islet morphometric studies demonstrated decreased beta-cell mass suggesting that this was a major component responsible for altered Insulin secretion and glucose intolerance in caCn(RIP) mice. The reduced beta-cell mass was accompanied by decreased proliferation and enhanced apoptosis. CONCLUSIONS:Our studies identify calcineurin as an important factor in controlling glucose homeostasis and indicate that chronic depolarization leading to increased calcineurin activity may contribute, along with other genetic and environmental factors, to beta-cell dysfunction and diabetes

    Generating long streams of 1/falpha1/f^alpha noise

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    We review existing methods for generating long streams of 1/f^alpha noise (0<α20<\alpha\le 2) focusing on the digital filtering of white noise. We detail the formalism to conceive an efficient random number generator (white outside some bounds) in order to generate very long streams of noise without an exhaustive computer memory load. For α=2\alpha=2 it is shown why the process is equivalent to a random-walk and can be obtained simply by a first order filtering of white noise. As soon as α<2\alpha<2 the problem becomes non linear and we show why the exact digital filtering method becomes inefficient. Instead, we work out the formalism of using several 1/f^2 filters spaced logarithmically, to approximate the spectrum at the percent level. Finally, from work on logistic maps, we give hints on how to design generators with α>2\alpha>2. The software is available from http://planck.lal.in2p3.fr/article.php3?id\_article=8Comment: Last version (corrected web site

    BioProject and BioSample databases at NCBI: facilitating capture and organization of metadata

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    As the volume and complexity of data sets archived at NCBI grow rapidly, so does the need to gather and organize the associated metadata. Although metadata has been collected for some archival databases, previously, there was no centralized approach at NCBI for collecting this information and using it across databases. The BioProject database was recently established to facilitate organization and classification of project data submitted to NCBI, EBI and DDBJ databases. It captures descriptive information about research projects that result in high volume submissions to archival databases, ties together related data across multiple archives and serves as a central portal by which to inform users of data availability. Concomitantly, the BioSample database is being developed to capture descriptive information about the biological samples investigated in projects. BioProject and BioSample records link to corresponding data stored in archival repositories. Submissions are supported by a web-based Submission Portal that guides users through a series of forms for input of rich metadata describing their projects and samples. Together, these databases offer improved ways for users to query, locate, integrate and interpret the masses of data held in NCBI's archival repositories. The BioProject and BioSample databases are available at http://www.ncbi.nlm.nih.gov/bioproject and http://www.ncbi.nlm.nih.gov/biosample, respectively

    DiRE: identifying distant regulatory elements of co-expressed genes

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    Regulation of gene expression in eukaryotic genomes is established through a complex cooperative activity of proximal promoters and distant regulatory elements (REs) such as enhancers, repressors and silencers. We have developed a web server named DiRE, based on the Enhancer Identification (EI) method, for predicting distant regulatory elements in higher eukaryotic genomes, namely for determining their chromosomal location and functional characteristics. The server uses gene co-expression data, comparative genomics and profiles of transcription factor binding sites (TFBSs) to determine TFBS-association signatures that can be used for discriminating specific regulatory functions. DiRE's unique feature is its ability to detect REs outside of proximal promoter regions, as it takes advantage of the full gene locus to conduct the search. DiRE can predict common REs for any set of input genes for which the user has prior knowledge of co-expression, co-function or other biologically meaningful grouping. The server predicts function-specific REs consisting of clusters of specifically-associated TFBSs and it also scores the association of individual transcription factors (TFs) with the biological function shared by the group of input genes. Its integration with the Array2BIO server allows users to start their analysis with raw microarray expression data. The DiRE web server is freely available at http://dire.dcode.org

    A previously functional tetracycline-regulated transactivator fails to target gene expression to the bone

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    <p>Abstract</p> <p>Background</p> <p>The tetracycline-controlled transactivator system is a powerful tool to control gene expression <it>in vitro </it>and to generate consistent and conditional transgenic <it>in vivo </it>model organisms. It has been widely used to study gene function and to explore pathological mechanisms involved in human diseases. The system permits the regulation of the expression of a target gene, both temporally and quantitatively, by the application of tetracycline or its derivative, doxycycline. In addition, it offers the possibility to restrict gene expression in a spatial fashion by utilizing tissue-specific promoters to drive the transactivator.</p> <p>Findings</p> <p>In this study, we report our problems using a reverse tetracycline-regulated transactivator (rtTA) in a transgenic mouse model system for the bone-specific expression of the Hutchinson-Gilford progeria syndrome mutation. Even though prior studies have been successful utilizing the same rtTA, expression analysis of the transactivator revealed insufficient activity for regulating the transgene expression in our system. The absence of transactivator could not be ascribed to differences in genetic background because mice in a mixed genetic background and in congenic mouse lines showed similar results.</p> <p>Conclusions</p> <p>The purpose of this study is to report our negative experience with previously functional transactivator mice, to raise caution in the use of tet-based transgenic mouse lines and to reinforce the need for controls to ensure the stable functionality of generated tetracycline-controlled transactivators over time.</p

    Identification of Radiopure Titanium for the LZ Dark Matter Experiment and Future Rare Event Searches

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    The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a detector containing a total of 10 tonnes of liquid xenon within a double-vessel cryostat. The large mass and proximity of the cryostat to the active detector volume demand the use of material with extremely low intrinsic radioactivity. We report on the radioassay campaign conducted to identify suitable metals, the determination of factors limiting radiopure production, and the selection of titanium for construction of the LZ cryostat and other detector components. This titanium has been measured with activities of 238^{238}Ue_{e}~<<1.6~mBq/kg, 238^{238}Ul_{l}~<<0.09~mBq/kg, 232^{232}The_{e}~=0.28±0.03=0.28\pm 0.03~mBq/kg, 232^{232}Thl_{l}~=0.25±0.02=0.25\pm 0.02~mBq/kg, 40^{40}K~<<0.54~mBq/kg, and 60^{60}Co~<<0.02~mBq/kg (68\% CL). Such low intrinsic activities, which are some of the lowest ever reported for titanium, enable its use for future dark matter and other rare event searches. Monte Carlo simulations have been performed to assess the expected background contribution from the LZ cryostat with this radioactivity. In 1,000 days of WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute only a mean background of 0.160±0.0010.160\pm0.001(stat)±0.030\pm0.030(sys) counts.Comment: 13 pages, 3 figures, accepted for publication in Astroparticle Physic
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