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Construction, characterization and chromosomal mapping of bacterial artificial chromosome (BAC) library of Yunnan snub-nosed monkey (Rhinopithecus bieti).

We constructed a high redundancy bacterial artificial chromosome library of a seriously endangered Old World Monkey, the Yunnan snub-nosed monkey (Rhinopithecus bieti) from China. This library contains a total of 136 320 BAC clones. The average insert size of BAC clones was estimated to be 148 kb. The percentage of small inserts (50-100 kb) is 2.74%, and only 2.67% non-recombinant clones were observed. Assuming a similar genome size with closely related primate species, the Yunnan snub-nosed monkey BAC library has at least six times the genome coverage. By end sequencing of randomly selected BAC clones, we generated 201 sequence tags for the library. A total of 139 end-sequenced BAC clones were mapped onto the chromosomes of Yunnan snub-nosed monkey by fluorescence in-situ hybridization, demonstrating a high degree of synteny conservation between humans and Yunnan snub-nosed monkeys. Blast search against human genome showed a good correlation between the number of hit clones and the size of the chromosomes, an indication of unbiased chromosomal distribution of the BAC library. This library and the mapped BAC clones will serve as a valuable resource in comparative genomics studies and large-scale genome sequencing of nonhuman primates. The DNA sequence data reported in this paper were deposited in GenBank and assigned the accession number CG891489-CG891703.

Animals↗

Conservation genetics and demographic history of the endangered Cape Fear shiner (Notropis mekistocholas).

We examined allelic variation at 22 nuclear-encoded markers (21 microsatellites and one anonymous locus) and mitochondrial (mt)DNA in two geographical samples of the endangered cyprinid fish Notropis mekistocholas (Cape Fear shiner). Genetic diversity was relatively high in comparison to other endangered vertebrates, and there was no evidence of small population effects despite the low abundance reported for the species. Significant heterogeneity (following Bonferroni correction) in allele distribution at three microsatellites and in haplotype distribution in mtDNA was detected between the two localities. This heterogeneity may be due to reduced gene flow caused by a dam built in the early 1900 s. Bayesian coalescent analysis of microsatellite variation indicated that effective population size of Cape Fear shiners has declined in recent times (11-25 435 years ago, with highest posterior probabilities between 126 and 2007 years ago) by one-two orders of magnitude, consistent with the observed decline in abundance of the species. A decline in effective size was not indicated by analysis of mtDNA, where sequence polymorphism appeared to carry the signature of an older expansion phase that dated to the Pleistocene ( approximately 12 700 > 1 million years ago). Cape Fear shiners thus appear to have undergone an expansion phase following a glacial cycle but to have declined significantly in more recent times. These results suggest that rapidly evolving markers such as microsatellites may constitute a suitable tool when inferring recent demographic dynamics of populations.

Animals↗

Identification and molecular cloning of a novel neuromedin U analog from the skin secretions of toad Bombina maxima.

Amphibian skin contains rich neuropeptides. In the present study, a novel neuromedin U (NmU) analog was isolated from skin secretions of Chinese red belly toad Bombina maxima. Being 17-amino acids long, its primary structure was established as DSSGIVGRPFFLFRPRN-NH2, in which the C-terminal 8-residue segment (FFLFRPRN) is the same as that of rat NmU, while the N-terminal part DSSGIVGRP shows a great sequence variation compared with those of NmU peptides from different resources. The peptide, named Bm-NmU-17, was found to elicit concentration-dependent contractile effects on smooth muscle of rat uterus horns. The cDNA structure of the peptide, as obtained by a 3'-RACE strategy and subsequently cloning from a skin cDNA library, was found to contain a coding region of 438 nucleotides. The encoded precursor is composed of 145 amino acids with a single copy of Bm-NmU-17 located towards the C-terminus. The sequence of the peptide is preceded by a dibasic site (Lys-Arg) and followed by the sequence of Gly-Arg-Lys, providing the sites of cleavage and releasing of the mature peptide.

Amino Acid Sequence↗

Changes in bacterial community during fermentative hydrogen and acid production from organic waste by thermophilic anaerobic microflora.

AIMS: Changes in fermentation pattern during the treatment of organic wastes containing solid materials by thermophilic anaerobic microflora were investigated with respect to product formation and bacterial community structure during hydrogen production. METHODS AND RESULTS: Anaerobic microflora enriched from sludge compost was cultivated using artificial garbage slurry in a continuous flow-stirred tank reactor. Product formation varied depending on pH and hydraulic retention time (HRT) applied. Community analysis by terminal restriction fragment length polymorphism and clone library analysis of polymerase chain reaction-amplified bacterial 16S rDNA indicated that difference in the fermentative product distribution could be caused by different populations of micro-organisms in the microflora. CONCLUSION: Hydrogen fermentation with acetate/butyrate formation was optimized at <1.0 d HRT at pH 5.0 and 6.0. Thermoanaerobacterium thermosaccharolyticum was the dominant hydrogen-producing micro-organism. Conversely, unidentified organisms became dominant after 4.0 d HRT at pH 7.0 and 8.0, where relatively high-solubilization efficiency of solid materials was observed with no production of hydrogen. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report describing product formation in the fermentation of solid organic wastes by a mixed population of micro-organisms. Various fermentation patterns including hydrogen fermentation were characterized and evaluated from engineering and microbial aspects.

Acids↗

Phylogeography of the Patelloida profunda group (Gastropoda: Lottidae): diversification in a dispersal-driven marine system.

In the last decade, greater than expected levels of genetic structure have been reported for many marine taxa with high dispersal capabilities. Although little-studied to date, it is predicted that taxa with poor dispersal abilities would exhibit even more genetic differentiation than high dispersal taxa. These systems may track biogeographical processes better than more dispersive taxa and, more critically, function as the 'lowest common denominators' in MPA design initiatives. We investigate phylogeographical patterns in the poorly dispersing, yet widely distributed Patelloida profunda group and related congeners across the Indo-west Pacific region. One hundred and twenty-five individuals were sequenced for COI mtDNA [593 base pairs (bp)] and 44 individuals were sequenced for 16S mtDNA (539 bp). Identified P. profunda group lineages are highly geographically structured, with 12 reciprocally monophyletic lineages reported from 13 localities. Divergences within Indian and Pacific basins range from d = 0.013 to 0.127 and between basins from d = 0.147 to 0.197. The latter split is ancient (> 15 Myr) and cannot be related to Plio-Pleistocene sea-level fluctuations, characteristic of previously reported divergences in the same region. Juxtaposed against this structure is genetic connectivity between two widely separated P. profunda populations that share a common haplotype (phiST = 0.001). This finding contrasts with previous work in the same geographical region and cautions strongly against single taxon indicators for designing conservation priorities or marine protected areas (MPAs). Historical and/or biological factors may play more significant roles than oceanography alone in determining the genetic structuring of taxa. In light of these findings, we discuss the difficulty in deriving biogeographical process or directionality from phylogenetic trees in dispersal-driven systems. Even with a well-resolved, highly supported topology, many equally parsimonious scenarios are possible.

Animals↗

Kazusa mammalian cDNA resources: towards functional characterization of KIAA gene products.

The Kazusa cDNA project pioneered an extensive sequencing project of human cDNAs in their entirety and focused sequencing efforts particularly on large cDNAs encoding large proteins. More than 2000 human genes, referred to as 'KIAA' genes, were initially identified through this cDNA project. Since many KIAA genes still remain functionally uncharacterized, our current focus is to determine their biological functions in vivo. In this review, we describe the current status of the Kazusa mammalian cDNA resources and the future direction of the functional characterization of KIAA genes.

Animals↗

Comparative performance of portable DNA extraction protocols and bioinformatics workflows for rapid detection of gram-negative bacteria and antimicrobial resistance using Oxford Nanopore sequencing.

Oxford Nanopore Technology (ONT) enables rapid, portable pathogen identification and antimicrobial resistance (AMR) detection, but the reliability of downstream genomic analyses is highly dependent on DNA extraction quality, particularly in resource-limited settings. This study comparatively evaluated four portable bacterial DNA extraction protocols derived from three commercial kits to determine their impact on nanopore sequencing performance, bioinformatics workflow completion, and field deployability. Six gram-negative bacterial isolates (Escherichia coli, n = 4; Pseudomonas sp., n = 1; and Salmonella sp., n = 1) were processed using four extraction protocols: SwiftX DNA, SwiftX DNA with proteinase K (ProtK), SwiftX ParaBact, and NucleoSpin Microbial. Twenty-four resulting DNA extracts were sequenced on a single multiplexed MinION R10.4.1 flow cell. Sequencing data were analyzed using validated Galaxy-based generic and species-specific pipelines. Workflow completion was defined as successful progression through quality control, assembly, virulence, plasmid, and AMR detection modules. DNA purity varied substantially by extraction protocol and was strongly associated with successful workflow completion (Kruskal-Wallis, P = 0.0006). Accordingly, NucleoSpin Microbial achieved 100% workflow completion, and SwiftX ParaBact achieved 83%, while both SwiftX DNA-based protocols failed to complete full workflows. Importantly, key AMR genes required to classify isolates as multidrug-resistant were consistently detected using both NucleoSpin Microbial and SwiftX ParaBact extractions. However, NucleoSpin Microbial assemblies showed significantly higher contiguity and enabled a broader, more complete detection of virulence factors, pathogenicity islands, plasmid replicons, and accessory AMR genes, reflecting enhanced genomic resolution.IMPORTANCERapid whole-genome sequencing is increasingly used to detect antimicrobial resistance and guide public health responses, but its reliability depends strongly on how bacterial DNA is extracted. In this study, we have shown that DNA extraction method choice has a major impact on Oxford Nanopore sequencing performance across clinically relevant gram-negative bacteria. While silica column-based extraction maximized genomic completeness and analytical depth, paramagnetic bead-based reverse purification offered superior portability with sufficient resolution for frontline AMR surveillance. These findings highlight a practical trade-off between field deployability and high-resolution genomic characterization in low-resource settings.

DNA extraction↗

A QTL resource and comparison tool for pigs: PigQTLDB.

During the past decade, efforts to map quantitative trait loci (QTL) in pigs have resulted in hundreds of QTL being reported for growth, meat quality, reproduction, disease resistance, and other traits. It is a challenge to locate, interpret, and compare QTL results from different studies. We have developed a pig QTL database (PigQTLdb) that integrates available pig QTL data in the public domain, thus, facilitating the use of this QTL data in future studies. We also developed a pig trait classification system to standardize names of traits and to simplify organization and searching of the trait data. These steps made it possible to compare primary data from diverse sources and methods. We used existing pig map databases and other publicly available data resources (such as PubMed) to avoid redundant developmental work. The PigQTLdb was also designed to include data representing major genes and markers associated with a large effect on economically important traits. To date, over 790 QTL from 73 publications have been curated into the database. Those QTL cover more than 300 different traits. The data have been submitted to the Entrez Gene and the Map Viewer resources at NCBI, where the information about markers was matched to marker records in NCBI's UniSTS database. Having these data in a public resource like NCBI allows regularly updated automatic matching of markers to public sequence data by e-PCR. The submitted data, and the results of these calculations, are retrievable from NCBI via Entrez Gene, Map Viewer, and UniSTS. Efforts were undertaken to improve the integrated functional genomics resources for pigs.

Animals↗

A large database of chicken bursal ESTs as a resource for the analysis of vertebrate gene function.

Chicken B cells create their immunoglobulin repertoire within the Bursa of Fabricius by gene conversion. The high homologous recombination activity is shared by the bursal B-cell-derived DT40 cell line, which integrates transfected DNA constructs at high rates into its endogenous loci. Targeted integration in DT40 is used frequently to analyze the function of genes by gene disruption. In this paper, we describe a large database of >7000 expressed sequence tags (ESTs) from bursal lymphocytes that should be a valuable resource for the identification of gene disruption targets in DT40. ESTs of interest can be recognized easily by online or keyword searches. Because the database reflects the gene expression profile of bursal lymphocytes, it provides valuable hints as to which genes might be involved in B-cell-specific processes related to immunoglobulin repertoire formation, signal transduction, transcription, and apoptosis. This large collection of chicken ESTs will also be useful for gene expression studies and comparative gene mapping within the chicken genome project. Details of the bursal EST sequencing project and access to database search forms can be found on the DT40 web site (http://genetics.hpi.uni-hamburg.de/dt40.html).

Animals↗

MRC-Wellcome Trust Human Developmental Biology Resource: enabling studies of human developmental gene expression.

A striking finding of the human and mouse genome sequencing projects is that, although there are many differences between the two species, they have similar numbers of genes. The differences arise during development and are driven, in part, by changes in gene expression. The MRC-Wellcome Trust Human Developmental Biology Resource (HDBR) is a unique resource that provides human embryonic and foetal tissues to the scientific community, enabling gene-expression studies at these crucial periods of development.

Animals↗

Study of simple sequence repeat (SSR) markers from wheat expressed sequence tags (ESTs).

The increasing availability of expressed sequence tags (ESTs) in wheat ( Triticum aestivum) and related cereals provides a valuable resource of non-anonymous DNA molecular markers. We examined 170,746 wheat ESTs from the public (International Triticeae EST Cooperative) and Génoplante databases, previously clustered in contigs, for the presence of di- to hexanucleotide simple sequence repeats (SSRs). Analysis of 46,510 contigs identified 3,530 SSRs, which represented 7.5% of the total number of contigs. Only 74% of the sequences allowed primer pairs to be designed, 70% led to an amplification product, mainly of a high quality (68%), and 53% exhibited polymorphism for at least one cultivar among the eight tested. Even though dinucleotide SSRs were less represented than trinucleotide SSRs (15.5% versus 66.5%, respectively), the former showed a much higher polymorphism level (83% versus 46%). The effect of the number and type of repeats is also discussed. The development of new EST-SSRs markers will have important implications for the genetic analysis and exploitation of the genetic resources of wheat and related species and will provide a more direct estimate of functional diversity.

Breeding↗

An integrated human immunoglobulin germline resource linking allele diversity to expressed repertoire structure.

Human immunoglobulin (IG) loci are highly polymorphic, yet existing germline resources remain noisy and incomplete, limiting our ability to link inherited variation to antibody repertoires. Here, we integrate high-fidelity long-read genomic sequencing with matched adaptive immune receptor repertoire sequencing (AIRR-seq) to construct HUSA, a population-scale, evidence-resolved germline resource. Using a conservative allele inference framework, HUSA expands current references more than three-fold, identifying over 1300 alleles while preserving allele-level evidence provenance across genomic and repertoire data. By linking genotype and expressed repertoires within individuals, we show that coding-region similarity predicts the structure of adjacent recombination signal sequences and leader regions, revealing that IG alleles are organized as linked cis-regulatory units associated with differences in recombination context and allele usage. These results define key germline constraints shaping repertoire formation and establish a robust, genotype-aware foundation for the analysis of immune receptor repertoires.

Journal Article↗

The Genome Sequence DataBase (GSDB): improving data quality and data access.

In 1997 the primary focus of the Genome Sequence DataBase (GSDB; www. ncgr.org/gsdb ) located at the National Center for Genome Resources was to improve data quality and accessibility. Efforts to increase the quality of data within the database included two major projects; one to identify and remove all vector contamination from sequences in the database and one to create premier sequence sets (including both alignments and discontiguous sequences). Data accessibility was improved during the course of the last year in several ways. First, a graphical database sequence viewer was made available to researchers. Second, an update process was implemented for the web-based query tool, Maestro. Third, a web-based tool, Excerpt, was developed to retrieve selected regions of any sequence in the database. And lastly, a GSDB flatfile that contains annotation unique to GSDB (e.g., sequence analysis and alignment data) was developed. Additionally, the GSDB web site provides a tool for the detection of matrix attachment regions (MARs), which can be used to identify regions of high coding potential. The ultimate goal of this work is to make GSDB a more useful resource for genomic comparison studies and gene level studies by improving data quality and by providing data access capabilities that are consistent with the needs of both types of studies.

Base Sequence↗

Grouping of accessions of Mexican races of maize revisited with SSR markers.

Mexican races of maize (Zea mays L.) represent a valuable genetic resource for breeding and genetic surveys. We applied simple sequence repeat (SSR) markers to characterize 25 accessions of races of maize from Mexico. Our objectives were to (1) study the molecular genetic diversity within and among these accessions and (2) examine their relationships as assumed previously on the basis of morphological data. A total of 497 individuals were fingerprinted with 25 SSR markers. We observed a high total number of alleles (7.84 alleles per locus) and total gene diversity (0.61), confirming the broad genetic base of the maize races from Mexico. In addition, the accessions were grouped into distinct racial complexes on the basis of a model-based clustering approach. The principal coordinate analyses of the four Modern Incipient hybrids corroborated the proposed parental races of Chalqueño, Cónico Norteño, Celaya, and Bolita on the basis of the morphological data. Consequently, for some of the accessions, hybridizations provide a clue that can further be used to explain the associations among the Mexican races of maize.

Alleles↗

Foliar disease resistance phenomics of fungal pathogens: image-based approaches for mapping quantitative resistance in cereal germplasm.

Host plant resistance is the most effective and environmentally sustainable means of reducing yield losses caused by fungal foliar pathogens of cereal species. Cereal genebank collections hold diverse pools of potentially underutilized disease resistance alleles, and cereal genomic resources are well advanced due to large-scale sequencing and genotyping efforts. Genome-Wide Association Studies (GWAS) have emerged as the predominant association genetics technique to initially discover novel disease resistance loci or alleles in these diverse collections. Traditional disease resistance phenotyping methods are reliant on visual estimation of disease symptom severity and have successfully supported genetic mapping studies either via GWAS or QTL mapping in biparental populations facilitating both marker development and gene cloning efforts. Due to foliar pathogens having a high capacity to evolve, there is a need to pyramid disease resistance genes with diverse mechanisms for durable control. Resistance expressed as a quantitative trait, known as quantitative resistance (QR), is hypothesized to be more durable, unlike major R-gene resistance that is race-specific and can be vulnerable to breaking down without gene stewardship. However, assessing QR visually is challenging, particularly when complicated by complex genotype&#x2009;&#xd7;&#x2009;environment (G&#x2009;&#xd7;&#x2009;E) effects in the field. High-throughput image-based phenotyping provides accurate and unbiased data that can support foliar disease resistance screening efforts of genebank collections using GWAS. In this review, we discuss image-based disease phenotyping based on macroscopic (visible symptoms) and microscopic features during the host-pathogen interaction. Quantitative image analysis approaches using conventional and artificial intelligence (AI) algorithms are also discussed.

Disease Resistance↗

In-silico identification of chicken immune-related genes.

In order to increase the resources available in chicken, a large-scale expressed sequence tag (EST) project was recently undertaken, resulting in the addition of more than 330,000 sequences to the databases. With the sequencing of further EST collections, there are now more than 460,000 chicken EST sequences publicly available (http://www.ncbi.nlm.nih.gov/). Previous analyses of the EST data estimate that the chicken genome may contain up to 35,000 genes. However, human data indicate that there may only be around 25,000, although there may be many more transcripts than actual genes. Here we describe how we used a bioinformatics approach with this large EST collection in order to identify immune-related genes, many of which were previously unreported in the chicken. The ESTs include cytokines, chemokines, antigens, cell surface proteins, receptors and MHC-associated genes. The identification of these kinds of genes will allow further study of avian immunology and will pave the way for large-scale immune-related microarray experiments, giving new insight into functional and evolutionary studies.

Animals↗

22-Mb integrated physical and genetic map based on YAC/STS content spanning the interval DXS1125-DXS95 in human Xq12-q21.31.

A YAC/STS map has been assembled spanning 22 Mb across Xq12-q21.31, between markers DXS1125 and DXS95. In addition to the landmark loci for the X-inactivation center XIST and the ATRX, ATP7A, phosphoglycerate kinase, POU3F4, and choroideremia genes, the candidate disease gene regions for torsion dystonia 3 and two X-linked mental retardation syndromes are included. Also, the human voltage-dependent anion channel gene (HVDAC1) has been placed near DXS986. The current map incorporates 211 YACs from five different libraries, formatted with 185 STSs that comprise 26 genetic linkage markers, 60 newly-developed YAC-end STSs, and eight ESTs. The multiple clone coverage and average resolution of one STS per 120 kb provide resources for disease gene searches and are facilitating complete sequencing of the region.

Base Sequence↗

European consortia building integrated resources for Arabidopsis functional genomics.

European laboratories specializing in functional genomics technologies collaborate in several consortia to build resources that facilitate gene function discovery in Arabidopsis thaliana. These resources include CATMA (a repertoire of gene-specific sequence tags), CAGE (a compendium of transcript profiles), AGRIKOLA (which consists of plasmids and mutant lines for gene silencing), ORFEUS (a collection of open reading frames) and SAP (a collection of promoter regions).

Arabidopsis↗