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Computer data base containing information about gene localization in the chromosomes of various organisms is composed. Computer program of genetic map constructing is created. The program represents graphically the information conserving in the data base. The data base and the program are intended for realization on the IBM-compatible computers.
Genetic markers such as single nucleotide polymorphisms (SNPs) are essential tools for positional cloning, association, or quantitative trait locus mapping and the determination of genetic relationships between individuals. We identified and characterized a genome-wide set of SNP markers by generating 10,706 expressed sequence tags (ESTs) from cDNA libraries derived from 6 different accessions, and by analysis of 606 sequence tagged sites (STS) from up to 12 accessions of the model flowering plant Arabidopsis thaliana. The cDNA libraries for EST sequencing were made from individuals that were stressed by various means to enrich for transcripts from genes expressed under such conditions. SNPs discovered in these sequences may be useful markers for mapping genes involved in interactions with the biotic and abiotic environment. The STS loci are distributed randomly over the genome. By comparison with the Col-0 genome sequence, we identified a total of 8051 SNPs and 637 insertion/deletion polymorphisms (InDel). Analysis of STS-derived SNPs shows that most SNPs are rare, but that it is possible to identify intermediate frequency framework markers that can be used for genetic mapping in many different combinations of accessions. A substantial proportion of SNPs located in ORFs caused a change of the encoded amino acid. A comparison of the density of our SNP markers among accessions in both the EST and STS datasets, revealed that Cvi-0 is the most divergent accession from Col-0 among the 12 accessions studied. All of these markers are freely available via the internet.
The updated version of PLMItRNA reports information and multialignments on 609 genes and 34 tRNA molecules active in the mitochondria of Viridiplantae (27 Embryophyta and 10 Chlorophyta), and photosynthetic algae (one Cryptophyta, four Rhodophyta and two Stramenopiles). Colour-code based tables reporting the different genetic origin of identified genes allow hyper-textual link to single entries. Promoter sequences identified for tRNA genes in the mitochondrial genomes of Angiospermae are also reported. The PLMItRNA database is accessible at http://bighost.area.ba.cnr.it/PLMItRNA/.
To identify the gene underlying a human genetic disorder can be difficult and time-consuming. Typically, positional data delimit a chromosomal region that contains between 20 and 200 genes. The choice then lies between sequencing large numbers of genes, or setting priorities by combining positional data with available expression and phenotype data, contained in different internet databases. This process of examining positional candidates for possible functional clues may be performed in many different ways, depending on the investigator's knowledge and experience. Here, we report on a new tool called the GeneSeeker, which gathers and combines positional data and expression/phenotypic data in an automated way from nine different web-based databases. This results in a quick overview of interesting candidate genes in the region of interest. The GeneSeeker system is built in a modular fashion allowing for easy addition or removal of databases if required. Databases are searched directly through the web, which obviates the need for data warehousing. In order to evaluate the GeneSeeker tool, we analysed syndromes with known genesis. For each of 10 syndromes the GeneSeeker programme generated a shortlist that contained a significantly reduced number of candidate genes from the critical region, yet still contained the causative gene. On average, a list of 163 genes based on position alone was reduced to a more manageable list of 22 genes based on position and expression or phenotype information. We are currently expanding the tool by adding other databases. The GeneSeeker is available via the web-interface (http://www.cmbi.kun.nl/GeneSeeker/).
The CEPH consortium framework map of chromosome 11 is presented. The map was generated from CEPH family DNAs with 181 probe/enzyme combinations contributed by 20 laboratories. Seventy-seven of the loci are defined by microsatellite polymorphisms that can be typed by the PCR. A total of 42 loci have been placed on the map with likelihood support of at least 1000:1. The female, male, and sex-average maps extend for 179.6, 110.8, and 145.3 cM, respectively. The largest interval on the sex-average map is less than 11 cM, and the average distance between uniquely placed loci is 4 cM. The genotypic data obtained for map construction have been used to identify the positions of crossovers on the chromosomes of CEPH family children, allowing the localization of new markers without computationally intensive likelihood models and providing a basis for efficient extension of the linkage map to higher resolution.
Extrachromosomal circular DNA (eccDNA) refers to small, circular DNA molecules that originate from chromosomal sequences and are prevalent across nearly all eukaryotic organisms. In humans, eccDNAs are widely distributed in normal tissues, cancerous tissues, and body fluids, where they play important roles in tumorigenesis and are often associated with poor clinical outcomes. Given their biological and clinical significance, a well-integrated and high-quality database is essential for advancing eccDNA-related research. To address this need, we developed eccDNABase, a comprehensive and curated resource for browsing, searching, and analyzing eccDNAs across multiple species. The database systematically catalogs eccDNA-disease associations from diverse tissues and organisms. Currently, eccDNABase contains 1,875,452 eccDNA-disease associations, encompassing 8,398 ecDNA entries across nine species, 63 diseases, and healthy individuals. Each entry provides detailed information, including eccDNA ID, type, chromosomal localization, species, tissue or cell line source, disease name and Disease Ontology ID, overlap length and percentage with genes, oncogene overlap, detection method, and links to literature and source databases. Given its extensive and curated datasets, eccDNABase serves as a valuable resource for both basic and translational research, offering deeper insights into the role of eccDNA in health and disease. The database is publicly accessible at http://cgga.org.cn/eccDNABase/.
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Use of the World Wide Web ("the web") and our knowledge of human genetics are both currently expanding rapidly. By allowing swift, universal, and free access to data, the web has already played an important role in human genetics research. It has also begun to change the way that information is shared in clinical genetics and, to a lesser degree, affect how education in human genetics occurs. There are scores of web sites helpful to those interested in either research or clinical aspects of human genetics. The web and related communication technologies should continue to play increasingly important roles in human genetics.
Identifying genomic regions that have been targets of natural selection remains one of the most important and challenging areas of research in genetics. To this end, we report an analysis of 26,530 single nucleotide polymorphisms (SNPs) with allele frequencies that were determined in three populations. Specifically, we calculated a measure of genetic differentiation, F(ST), for each locus and examined its distribution at the level of the genome, the chromosome, and individual genes. Through a variety of analyses, we have found statistically significant evidence supporting the hypothesis that selection has influenced extant patterns of human genetic variation. Importantly, by contrasting the F(ST) of individual SNPs to the empirical genome-wide distribution of F(ST), our results are not confounded by tenuous assumptions of population demographic history. Furthermore, we have identified 174 candidate genes with distribution of genetic variation that indicates that they have been targets of selection. Our work provides a first generation natural selection map of the human genome and provides compelling evidence that selection has shaped extant patterns of human genomic variation.
The 'Atlas of Genetics and Cytogenetics in Oncology and Haematology' (http://www.infobiogen.fr/services/chromcancer ) is a database devoted to chromosome abnormalities in cancer, cancer-prone diseases and genes involved in cancer. Information presented in each page is concise and updated. This database is made for and by: cytogeneticists, molecular biologists, clinicians in oncology and in haematology, and pathologists, who are encouraged to contribute.
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PAHdb, a legacy of and resource in genetics, is a relational locus-specific database (http://www.pahdb.mcgill.ca). It records and annotates both pathogenic alleles (n = 439, putative disease-causing) and benign alleles (n = 41, putative untranslated polymorphisms) at the human phenylalanine hydroxylase locus (symbol PAH). Human alleles named by nucleotide number (systematic names) and their trivial names receive unique identifier numbers. The annotated gDNA sequence for PAH is typical for mammalian genes. An annotated gDNA sequence is numbered so that cDNA and gDNA sites are interconvertable. A site map for PAHdb leads to a large array of secondary data (attributes): source of the allele (submitter, publication, or population); polymorphic haplotype background; and effect of the allele as predicted by molecular modeling on the phenylalanine hydroxylase enzyme (EC 1.14.16.1) or by in vitro expression analysis. The majority (63%) of the putative pathogenic PAH alleles are point mutations causing missense in translation of which few have a primary effect on PAH enzyme kinetics. Most apparently have a secondary effect on its function through misfolding, aggregation, and intracellular degradation of the protein. Some point mutations create new splice sites. A subset of primary PAH mutations that are tetrahydrobiopterin-responsive is highlighted on a Curators' Page. A clinical module describes the corresponding human clinical disorders (hyperphenylalaninemia [HPA] and phenylketonuria [PKU]), their inheritance, and their treatment. PAHdb contains data on the mouse gene (Pah) and on four orthologous mutant mouse models and their use (for example, in research on oral treatment of PKU with the enzyme phenylalanine ammonia lyase [EC 4.3.1.5]).
BACKGROUND: Unrelated individuals (n = 242) were interviewed directly for the presence of migraine, anxiety disorders, and major depression. MATERIALS AND METHODS: The data described in this study are derived from a clinical genetic relational database that was developed initially for the genetic analysis of migraine. Genotyping of the DRD2 NcoI C to T polymorphism located in exon 6 (His313His) was performed using previously described primers. RESULTS: A significantly increased incidence of migraine with aura (MWA), major depression, generalized anxiety disorder (GAD), panic attacks, and phobia was observed in individuals with the DRD2 NcoI C/C genotype compared with individuals with an DRD2 NcoI T allele. Specifically, 69% (91/131) of DRD2 NcoI C/C individuals in the present study met criteria for at least one of these neuropsychiatric disorders versus only 22% (4/18) of the DRD2 NcoI T/T individuals (Chi-square = 15.29; p < 0.00005). The DRD2 NcoI C allele frequency is significantly higher (Chi-square = 17.13; p < 0.00002) in individuals with MWA, anxiety disorders, and/or major depression (C allele frequency = 0.80) than in individuals who have none of these disorders (C allele frequency = 0.67). CONCLUSIONS: These data indicate that MWA, anxiety disorders, and major depression can be components of a distinct clinical syndrome associated with allelic variations within the DRD2 gene. Clinical recognition of this genetically based syndrome has significant diagnostic and therapeutic implications.
BACKGROUND: For effective exposition of biological information, especially with regard to analysis of large-scale data types, researchers need immediate access to multiple categorical knowledge bases and need summary information presented to them on collections of genes, as opposed to the typical one gene at a time. RESULTS: We present here a web-based tool (FunSpec) for statistical evaluation of groups of genes and proteins (e.g. co-regulated genes, protein complexes, genetic interactors) with respect to existing annotations (e.g. functional roles, biochemical properties, localization). FunSpec is available online at http://funspec.med.utoronto.ca CONCLUSION: FunSpec is helpful for interpretation of any data type that generates groups of related genes and proteins, such as gene expression clustering and protein complexes, and is useful for predictive methods employing "guilt-by-association."
Single Nucleotide Polymorphisms (SNPs) are the most important source of variation in our genome, and an invaluable tool in the hands of researchers who investigate genetic diseases. Databases of SNPs are growing at a very fast rate, and the ability to perform large-scale, high-resolution association studies is quickly becoming a reality. In this paper we describe SNPper, a web-based tool to search for SNPs in public databases. The system allows searching for all SNPs in a given set of genes (for candidate gene studies) or in a specified region of a chromosome. The information displayed for each gene or each SNP is fully annotated and linked to the leading bioinformatics web sites. The first release of SNPper is available on the web, and has received positive feedback from the genetic and bioinformatics community.
The Histone Sequence Database is an annotated and searchable collection of all available histone and histone fold sequences and structures. Particular emphasis has been placed on documenting conflicts between similar sequence entries from a number of source databases, conflicts that are not necessarily documented in the source databases themselves. New additions to the database include compilations of post-translational modifications for each of the core and linker histones, as well as genomic information in the form of map loci for the human histone gene complement, with the genetic loci linked to Online Mendelian Inheritance in Man (OMIM). The database is freely accessible through the World Wide Web at either http://genome.nhgri.nih.gov/histones/ or http://www.ncbi.nlm.nih. gov/Baxevani/HISTONES
BackgroundPrior studies examined variants within presenilin-2 (PSEN2), presenilin-1 (PSEN1), and amyloid precursor protein (APP) genes. However, previously-reported clinically-relevant variants and other predicted damaging missense (DM) variants have not been characterized in a newer release of the Alzheimer's Disease Sequencing Project (ADSP).ObjectiveTo characterize previously-reported clinically-relevant variants and DM variants in PSEN2, PSEN1, APP within the participants from the ADSP.MethodsWe identified rare variants (MAF < 1%) in PSEN2, PSEN1, and APP in 14,641 individuals with whole genome sequencing and 16,849 individuals with whole exome sequencing available (Ntotal = 31,490). We additionally curated variants from ClinVar, OMIM, and Alzforum and report carriers of variants in clinical databases as well as predicted DM variants in these genes.ResultsWe detected 31 previously-reported clinically-relevant variants with alternate alleles observed within the ADSP: 4 variants in PSEN2, 25 in PSEN1, and 2 in APP. The overall variant carrier rate for the 31 clinically-relevant variants in the ADSP was 0.3%. We observed that 79.5% of the variant carriers were cases compared to 3.9% were controls. In those with AD, the mean age of onset of AD among carriers of these clinically-relevant variants was 19.6 ± 1.4 years earlier compared with noncarriers (p = 7.8 × 10-57). Additionally, we identified 197 rare variants (MAF < 1%) within ADSP participants not reported in known clinical databases.ConclusionsA small proportion of individuals in the ADSP are carriers of a previously-reported clinically-relevant variant allele for AD and these participants have significantly earlier age of AD onset compared to noncarriers.