132 research outputs found
The Orthologue of Sjögren's Syndrome Nuclear Autoantigen 1 (SSNA1) in Trypanosoma brucei Is an Immunogenic Self-Assembling Molecule
Primary Sjögren's Syndrome (PSS) is a highly prevalent autoimmune disease, typically manifesting as lymphocytic infiltration of the exocrine glands leading to chronically impaired lacrimal and salivary secretion. Sjögren's Syndrome nuclear autoantigen 1 (SSNA1 or NA14) is a major specific target for autoantibodies in PSS but the precise function and clinical relevance of this protein are largely unknown. Orthologues of the gene are absent from many of the commonly used model organisms but are present in Chlamyodomonas reinhardtii (in which it has been termed DIP13) and most protozoa. We report the functional characterisation of the orthologue of SSNA1 in the kinetoplastid parasite, Trypanosoma brucei. Both TbDIP13 and human SSNA1 are small coiled-coil proteins which are predicted to be remote homologues of the actin-binding protein tropomyosin. We use comparative proteomic methods to identify potential interacting partners of TbDIP13. We also show evidence that TbDIP13 is able to self-assemble into fibril-like structures both in vitro and in vivo, a property which may contribute to its immunogenicity. Endogenous TbDIP13 partially co-localises with acetylated α-tubulin in the insect procyclic stage of the parasite. However, deletion of the DIP13 gene in cultured bloodstream and procyclic stages of T. brucei has little effect on parasite growth or morphology, indicating either a degree of functional redundancy or a function in an alternative stage of the parasite life cycle
Bovine Genome Database: integrated tools for genome annotation and discovery
The Bovine Genome Database (BGD; http://BovineGenome.org) strives to improve annotation of the bovine genome and to integrate the genome sequence with other genomics data. BGD includes GBrowse genome browsers, the Apollo Annotation Editor, a quantitative trait loci (QTL) viewer, BLAST databases and gene pages. Genome browsers, available for both scaffold and chromosome coordinate systems, display the bovine Official Gene Set (OGS), RefSeq and Ensembl gene models, non-coding RNA, repeats, pseudogenes, single-nucleotide polymorphism, markers, QTL and alignments to complementary DNAs, ESTs and protein homologs. The Bovine QTL viewer is connected to the BGD Chromosome GBrowse, allowing for the identification of candidate genes underlying QTL. The Apollo Annotation Editor connects directly to the BGD Chado database to provide researchers with remote access to gene evidence in a graphical interface that allows editing and creating new gene models. Researchers may upload their annotations to the BGD server for review and integration into the subsequent release of the OGS. Gene pages display information for individual OGS gene models, including gene structure, transcript variants, functional descriptions, gene symbols, Gene Ontology terms, annotator comments and links to National Center for Biotechnology Information and Ensembl. Each gene page is linked to a wiki page to allow input from the research community
Identifying significant genetic regulatory networks in the prostate cancer from microarray data based on transcription factor analysis and conditional independency
<p>Abstract</p> <p>Background</p> <p>Prostate cancer is a world wide leading cancer and it is characterized by its aggressive metastasis. According to the clinical heterogeneity, prostate cancer displays different stages and grades related to the aggressive metastasis disease. Although numerous studies used microarray analysis and traditional clustering method to identify the individual genes during the disease processes, the important gene regulations remain unclear. We present a computational method for inferring genetic regulatory networks from micorarray data automatically with transcription factor analysis and conditional independence testing to explore the potential significant gene regulatory networks that are correlated with cancer, tumor grade and stage in the prostate cancer.</p> <p>Results</p> <p>To deal with missing values in microarray data, we used a K-nearest-neighbors (KNN) algorithm to determine the precise expression values. We applied web services technology to wrap the bioinformatics toolkits and databases to automatically extract the promoter regions of DNA sequences and predicted the transcription factors that regulate the gene expressions. We adopt the microarray datasets consists of 62 primary tumors, 41 normal prostate tissues from Stanford Microarray Database (SMD) as a target dataset to evaluate our method. The predicted results showed that the possible biomarker genes related to cancer and denoted the androgen functions and processes may be in the development of the prostate cancer and promote the cell death in cell cycle. Our predicted results showed that sub-networks of genes SREBF1, STAT6 and PBX1 are strongly related to a high extent while ETS transcription factors ELK1, JUN and EGR2 are related to a low extent. Gene SLC22A3 may explain clinically the differentiation associated with the high grade cancer compared with low grade cancer. Enhancer of Zeste Homolg 2 (EZH2) regulated by RUNX1 and STAT3 is correlated to the pathological stage.</p> <p>Conclusions</p> <p>We provide a computational framework to reconstruct the genetic regulatory network from the microarray data using biological knowledge and constraint-based inferences. Our method is helpful in verifying possible interaction relations in gene regulatory networks and filtering out incorrect relations inferred by imperfect methods. We predicted not only individual gene related to cancer but also discovered significant gene regulation networks. Our method is also validated in several enriched published papers and databases and the significant gene regulatory networks perform critical biological functions and processes including cell adhesion molecules, androgen and estrogen metabolism, smooth muscle contraction, and GO-annotated processes. Those significant gene regulations and the critical concept of tumor progression are useful to understand cancer biology and disease treatment.</p
Normalized long read RNA sequencing in chicken reveals transcriptome complexity similar to human
Background: Despite the significance of chicken as a model organism, our understanding of the chicken transcriptome is limited compared to human. This issue is common to all non-human vertebrate annotations due to the difficulty in transcript identification from short read RNAseq data. While previous studies have used single molecule long read sequencing for transcript discovery, they did not perform RNA normalization and 5'-cap selection which may have resulted in lower transcriptome coverage and truncated transcript sequences. Results: We sequenced normalised chicken brain and embryo RNA libraries with Pacific Bioscience Iso-Seq. 5' cap selection was performed on the embryo library to provide methodological comparison. From these Iso-Seq sequencing projects, we have identified 60 k transcripts and 29 k genes within the chicken transcriptome. Of these, more than 20 k are novel lncRNA transcripts with ~3 k classified as sense exonic overlapping lncRNA, which is a class that is underrepresented in many vertebrate annotations. The relative proportion of alternative transcription events revealed striking similarities between the chicken and human transcriptomes while also providing explanations for previously observed genomic differences. Conclusions: Our results indicate that the chicken transcriptome is similar in complexity compared to human, and provide insights into other vertebrate biology. Our methodology demonstrates the potential of Iso-Seq sequencing to rapidly expand our knowledge of transcriptomics
LIME -- a gas TPC prototype for directional Dark Matter search for the CYGNO experiment
The CYGNO experiment aims at the development of a large gaseous TPC with
GEM-based amplification and an optical readout by means of PMTs and scientific
CMOS cameras for 3D tracking down to O(keV) energies, for the directional
detection of rare events such as low mass Dark Matter and solar neutrino
interactions. The largest prototype built so far towards the realisation of the
CYGNO experiment demonstrator is the 50 L active volume LIME, with 4 PMTs and a
single sCMOS imaging a 3333 cm\textsuperscript{2} area for 50 cm drift,
that has been installed in underground Laboratori Nazionali del Gran Sasso in
February 2022. We will illustrate LIME performances as evaluated overground in
Laboratori Nazionali di Frascati by means of radioactive X-ray sources, and in
particular the detector stability, energy response and energy resolution. We
will discuss the MC simulation developed to reproduce the detector response and
show the comparison with actual data. We will furthermore examine the
background simulation worked out for LIME underground data taking and
illustrate the foreseen expected measurement and results in terms of natural
and materials intrinsic radioactivity characterisation and measurement of the
LNGS underground natural neutron flux. The results that will be obtained by
underground LIME installation will be paramount in the optimisation of the
CYGNO demonstrator, since this is foreseen to be composed by multiple modules
with the same LIME dimensions and characteristics
Multi-Platform Next-Generation Sequencing of the Domestic Turkey (Meleagris gallopavo): Genome Assembly and Analysis
The combined application of next-generation sequencing platforms has provided an economical approach to unlocking the potential of the turkey genome
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
The CYGNO Experiment
The search for a novel technology able to detect and reconstruct nuclear and
electron recoil events with the energy of a few keV has become more and more
important now that large regions of high-mass dark matter (DM) candidates have
been excluded. Moreover, a detector sensitive to incoming particle direction
will be crucial in the case of DM discovery to open the possibility of studying
its properties. Gaseous time projection chambers (TPC) with optical readout are
very promising detectors combining the detailed event information provided by
the TPC technique with the high sensitivity and granularity of
latest-generation scientific light sensors. The CYGNO experiment (a CYGNus
module with Optical readout) aims to exploit the optical readout approach of
multiple-GEM structures in large volume TPCs for the study of rare events as
interactions of low-mass DM or solar neutrinos. The combined use of
high-granularity sCMOS cameras and fast light sensors allows the reconstruction
of the 3D direction of the tracks, offering good energy resolution and very
high sensitivity in the few keV energy range, together with a very good
particle identification useful for distinguishing nuclear recoils from
electronic recoils. This experiment is part of the CYGNUS proto-collaboration,
which aims at constructing a network of underground observatories for
directional DM search. A one cubic meter demonstrator is expected to be built
in 2022/23 aiming at a larger scale apparatus (30 m--100 m) at a later
stage
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