Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Genomic sequencing”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

Canine distemper terminal and intergenic non-protein coding nucleotide sequences: completion of the entire CDV genome sequence.

Sequences critical for the transcription and replication functions of canine distemper virus (CDV) RNA polymerase were analyzed. The sequence was obtained from polymerase chain reaction (PCR) products using either c-DNA clones from a genomic library as template or in most instances genomic CDV RNA. Clones coding for the precise 3'- and 5'-ends of the CDV genome were sequenced and the results confirmed by additional PCR experiments. The virtual identity of terminal sequences and spacing at the two noncoding ends speak to the importance of these areas in replication and transcription. The sequence for each of the CDV gene boundaries was defined and all were compared to related viruses. This report completes the sequence determination of the CDV genome.

Base Sequence↗

[DNA analysis for the post genome-sequencing era].

With the completion of the human genome sequencing, the new post genome-sequencing era has started. The major subjects are clarifying the function of genes to apply this information to medical as well as various industrial fields. Various DNA analysis methods and instruments for gene expression profiling as well as genetic diversity including SNPs typing are required and have been developed. Here, the history and technologies related to DNA analysis including the Wada project in the early 1980's, and the Human genome project from 1990 are described. Various new technologies have developed in this decade. They include a capillary gel array DNA sequencer, DNA chips, bead probe arrays, a new DNA sequencing method using pyrosequencing and an efficient SNP typing method by BAMPER.

DNA↗

Specialized microbial databases for inductive exploration of microbial genome sequences.

BACKGROUND: The enormous amount of genome sequence data asks for user-oriented databases to manage sequences and annotations. Queries must include search tools permitting function identification through exploration of related objects. METHODS: The GenoList package for collecting and mining microbial genome databases has been rewritten using MySQL as the database management system. Functions that were not available in MySQL, such as nested subquery, have been implemented. RESULTS: Inductive reasoning in the study of genomes starts from "islands of knowledge", centered around genes with some known background. With this concept of "neighborhood" in mind, a modified version of the GenoList structure has been used for organizing sequence data from prokaryotic genomes of particular interest in China. GenoChore http://bioinfo.hku.hk/genochore.html, a set of 17 specialized end-user-oriented microbial databases (including one instance of Microsporidia, Encephalitozoon cuniculi, a member of Eukarya) has been made publicly available. These databases allow the user to browse genome sequence and annotation data using standard queries. In addition they provide a weekly update of searches against the world-wide protein sequences data libraries, allowing one to monitor annotation updates on genes of interest. Finally, they allow users to search for patterns in DNA or protein sequences, taking into account a clustering of genes into formal operons, as well as providing extra facilities to query sequences using predefined sequence patterns. CONCLUSION: This growing set of specialized microbial databases organize data created by the first Chinese bacterial genome programs (ThermaList, Thermoanaerobacter tencongensis, LeptoList, with two different genomes of Leptospira interrogans and SepiList, Staphylococcus epidermidis) associated to related organisms for comparison.

Algorithms↗

PeerGAD: a peer-review-based and community-centric web application for viewing and annotating prokaryotic genome sequences.

PeerGAD is a web-based database-driven application that allows community-wide peer-reviewed annotation of prokaryotic genome sequences. The application was developed to support the annotation of the Pseudomonas syringae pv. tomato strain DC3000 genome sequence and is easily portable to other genome sequence annotation projects. PeerGAD incorporates several innovative design and operation features and accepts annotations pertaining to gene naming, role classification, gene translation and annotation derivation. The annotator tool in PeerGAD is built around a genome browser that offers users the ability to search and navigate the genome sequence. Because the application encourages annotation of the genome sequence directly by researchers and relies on peer review, it circumvents the need for an annotation curator while providing added value to the annotation data. Support for the Gene Ontology vocabulary, a structured and controlled vocabulary used in classification of gene roles, is emphasized throughout the system. Here we present the underlying concepts integral to the functionality of PeerGAD.

Computational Biology↗

Genome sequence of Rickettsia bellii illuminates the role of amoebae in gene exchanges between intracellular pathogens.

The recently sequenced Rickettsia felis genome revealed an unexpected plasmid carrying several genes usually associated with DNA transfer, suggesting that ancestral rickettsiae might have been endowed with a conjugation apparatus. Here we present the genome sequence of Rickettsia bellii, the earliest diverging species of known rickettsiae. The 1,552,076 base pair-long chromosome does not exhibit the colinearity observed between other rickettsia genomes, and encodes a complete set of putative conjugal DNA transfer genes most similar to homologues found in Protochlamydia amoebophila UWE25, an obligate symbiont of amoebae. The genome exhibits many other genes highly similar to homologues in intracellular bacteria of amoebae. We sought and observed sex pili-like cell surface appendages for R. bellii. We also found that R. bellii very efficiently multiplies in the nucleus of eukaryotic cells and survives in the phagocytic amoeba, Acanthamoeba polyphaga. These results suggest that amoeba-like ancestral protozoa could have served as a genetic "melting pot" where the ancestors of rickettsiae and other bacteria promiscuously exchanged genes, eventually leading to their adaptation to the intracellular lifestyle within eukaryotic cells.

Actins↗

The sequence of the N and L genes of rinderpest virus, and the 5' and 3' extra-genic sequences: the completion of the genome sequence of the virus.

We have sequenced the nucleocapsid (N) and polymerase (L) genes of the vaccine strain of rinderpest, and the 5' and 3' terminal domains of the genome. Together with previously published data, this completes the sequence of the entire genome of rinderpest virus. The L gene is identical in length to that of measles virus, encoding a 2183 amino acid protein with a calculated molecular weight of 248,100. The L protein sequence of three morbilliviruses is highly conserved, greater than 76% of residues being identical or conserved in all sequences. The N protein was, as for other sequenced genes, essentially identical to that of the virulent parent. The viral genome is 15,881 bases in length, similar to that of measles virus and slightly longer than that of canine distemper virus. The terminal sequences of the genome and those at the gene boundaries were compared to the analogous regions of other morbilliviruses and representatives of related groups of paramyxoviruses.

Amino Acid Sequence↗

Computational methods for the identification of genes in vertebrate genomic sequences.

Research into new methods to identify genes in anonymous genomic sequences has been going on for more than 15 years. Over this period of time, the field has evolved from the designing of programs to identify protein coding regions in compact mitochondrial or bacterial genomes, to the challenge of predicting the detailed organization of multi-exon vertebrate genes. The best program currently available perfectly locates more than 80% of the internal coding exons, and only 5% of the predictions do not overlap a real exon. Given such accuracy, computational methods are indeed very useful; however, they do not alleviate the need for experimental validation. If the performances are satisfactory for the identification of the coding moiety of genes (internal coding exons), the determination of the full extent of the transcript (5' and 3' extremities of the gene) and the location of promoter regions are still unreliable. As the human and mouse genome sequencing projects enter a production mode, the fully automated annotation of megabase-long anonymous genomic sequences is the next big challenge in bioinformatics.

Animals↗

Insect mitochondrial genomics 2: The complete mitochondrial genome sequence of a giant stonefly, Pteronarcys princeps, asymmetric directional mutation bias, and conserved plecopteran A+T-region elements.

Mitochondrial (mt) genome sequences of insects are receiving renewed attention in molecular phylogentic studies, studies of mt-genome rearrangement, and other unusual molecular phenomena, such as translational frameshifting. At present, the basal neopteran lineages are poorly represented by mt-genome sequences. Complete mt-genome sequences are available in the databases for only the Orthoptera and Blatteria; 9 orders are unrepresented. Here, we present the complete mt-genome sequence of a giant stonefly, Pteronarcys princeps (Plecoptera; Pteronarcyidae). The 16,004 bp genome is typical in its genome content, gene organisation, and nucleotide composition. The genome shows evidence of strand-specific mutational biases, correlated with the time between the initiation of leading and the initiation of lagging strand replication. Comparisons with other insects reveal that this trend is seen in other insect groups, but is not universally consistent among sampled mt-genomes. The A+T region is compared with that of 2 stoneflies in the family Peltoperlidae. Conserved stem-loop structures and sequence blocks are noted between these distantly related families.

Animals↗

Entamoeba histolytica: observations on metabolism based on the genome sequence.

The sequencing of the genome of Entamoeba histolytica has allowed a reconstruction of its metabolic pathways, many of which are unusual for a eukaryote. Based on the genome sequence, it appears that amino acids may play a larger role than previously thought in energy metabolism, with roles in both ATP synthesis and NAD regeneration. Arginine decarboxylase may be involved in survival of E. histolytica during its passage through the stomach. The usual pyrimidine synthesis pathway is absent, but a partial pyrimidine degradation pathway could be part of a novel pyrimidine synthesis pathway. Ribonucleotide reductase was not found in the E. histolytica genome, but it was found in the close relatives Entamoeba invadens and Entamoeba moshkovskii, suggesting a recent loss from E. histolytica. The usual eukaryotic glucose transporters are not present, but members of a prokaryotic monosaccharide transporter family are present.

Amino Acids↗

Genomic typing of Pseudomonas aeruginosa isolates by comparison of Riboprinting and PFGE: correlation of experimental results with those predicted from the complete genome sequence of isolate PAO1.

The whole genomic typing of 21 isolates of Pseudomonas aeruginosa from 15 intensive care unit (ICU) patients was performed by pulsed-field gel electrophoresis (PFGE using SpeI) and Riboprinting (using EcoRI and PvuII), and then the results were compared with predictions made from the whole genome sequence of P. aeruginosa PAO1. The analysis of electronic images from PFGE and Riboprinting by GelComparII demonstrated similar discrimination between PFGE and Riboprinting with PvuII enzyme; however, Riboprinting by EcoRI had reduced banding patterns and was shown to be of lower discrimination than PvuII. When analyzing isolates from patients, both PFGE and Riboprinting using PvuII enzyme gave equivalent results, with the exception of two isolates that were closely related by PvuII Riboprinting and unrelated by PFGE. These discrepancies in typing results can be explained and adjusted for by comparisons with the rrn properties and the SpeI restriction fragments predicted from the whole genome of P. aeruginosa PAO1. Properties of the rrn operon that need to be taken into account include: (i) restriction enzyme sites that produce one or two fragments for each rrn operon; (ii) genomic variability in ISR sequence length; (iii) different enzymes need to be used to determine differences in rrn operon copy number from Riboprints; and (iv) choice of a restriction enzyme that produces riboprinter bands derived from rrn operon regions that are highly variable within the genome and between isolates. This knowledge has ramifications for PFGE and Riboprinter design and analysis so that for each new species to be typed comparisons can be made using the whole genome sequence.

Bacterial Typing Techniques↗

Genomic sequence of a ranavirus (family Iridoviridae) associated with salamander mortalities in North America.

Disease is among the suspected causes of amphibian population declines, and an iridovirus and a chytrid fungus are the primary pathogens associated with amphibian mortalities. Ambystoma tigrinum virus (ATV) and a closely related strain, Regina ranavirus (RRV), are implicated in salamander die-offs in Arizona and Canada, respectively. We report the complete sequence of the ATV genome and partial sequence of the RRV genome. Sequence analysis of the ATV/RRV genomes showed marked similarity to other ranaviruses, including tiger frog virus (TFV) and frog virus 3 (FV3), the type virus of the genus Ranavirus (family Iridoviridae), as well as more distant relationships to lymphocystis disease virus, Chilo iridescent virus, and infectious spleen and kidney necrosis virus. Putative open reading frames (ORFs) in the ATV sequence identified 24 genes that appear to control virus replication and block antiviral responses. In addition, >50 other putative genes, homologous to ORFs in other iridoviral genomes but of unknown function, were also identified. Sequence comparison performed by dot plot analysis between ATV and itself revealed a conserved 14-bp palindromic repeat within most intragenic regions. Dot plot analysis of ATV vs RRV sequences identified several polymorphisms between the two isolates. Finally, a comparison of ATV and TFV genomic sequences identified genomic rearrangements consistent with the high recombination frequency of iridoviruses. Given the adverse effects that ranavirus infections have on amphibian and fish populations, ATV/RRV sequence information will allow the design of better diagnostic probes for identifying ranavirus infections and extend our understanding of molecular events in ranavirus-infected cells.

Animals↗

The diploid genome sequence of Candida albicans.

We present the diploid genome sequence of the fungal pathogen Candida albicans. Because C. albicans has no known haploid or homozygous form, sequencing was performed as a whole-genome shotgun of the heterozygous diploid genome in strain SC5314, a clinical isolate that is the parent of strains widely used for molecular analysis. We developed computational methods to assemble a diploid genome sequence in good agreement with available physical mapping data. We provide a whole-genome description of heterozygosity in the organism. Comparative genomic analyses provide important clues about the evolution of the species and its mechanisms of pathogenesis.

Candida albicans↗

Lessons from the genome sequence of Neurospora crassa: tracing the path from genomic blueprint to multicellular organism.

We present an analysis of over 1,100 of the approximately 10,000 predicted proteins encoded by the genome sequence of the filamentous fungus Neurospora crassa. Seven major areas of Neurospora genomics and biology are covered. First, the basic features of the genome, including the automated assembly, gene calls, and global gene analyses are summarized. The second section covers components of the centromere and kinetochore complexes, chromatin assembly and modification, and transcription and translation initiation factors. The third area discusses genome defense mechanisms, including repeat induced point mutation, quelling and meiotic silencing, and DNA repair and recombination. In the fourth section, topics relevant to metabolism and transport include extracellular digestion; membrane transporters; aspects of carbon, sulfur, nitrogen, and lipid metabolism; the mitochondrion and energy metabolism; the proteasome; and protein glycosylation, secretion, and endocytosis. Environmental sensing is the focus of the fifth section with a treatment of two-component systems; GTP-binding proteins; mitogen-activated protein, p21-activated, and germinal center kinases; calcium signaling; protein phosphatases; photobiology; circadian rhythms; and heat shock and stress responses. The sixth area of analysis is growth and development; it encompasses cell wall synthesis, proteins important for hyphal polarity, cytoskeletal components, the cyclin/cyclin-dependent kinase machinery, macroconidiation, meiosis, and the sexual cycle. The seventh section covers topics relevant to animal and plant pathogenesis and human disease. The results demonstrate that a large proportion of Neurospora genes do not have homologues in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. The group of unshared genes includes potential new targets for antifungals as well as loci implicated in human and plant physiology and disease.

Animals↗

Towards understanding the first genome sequence of a crenarchaeon by genome annotation using clusters of orthologous groups of proteins (COGs).

BACKGROUND: Standard archival sequence databases have not been designed as tools for genome annotation and are far from being optimal for this purpose. We used the database of Clusters of Orthologous Groups of proteins (COGs) to reannotate the genomes of two archaea, Aeropyrum pernix, the first member of the Crenarchaea to be sequenced, and Pyrococcus abyssi. RESULTS: A. pernix and P. abyssi proteins were assigned to COGs using the COGNITOR program; the results were verified on a case-by-case basis and augmented by additional database searches using the PSI-BLAST and TBLASTN programs. Functions were predicted for over 300 proteins from A. pernix, which could not be assigned a function using conventional methods with a conservative sequence similarity threshold, an approximately 50% increase compared to the original annotation. A. pernix shares most of the conserved core of proteins that were previously identified in the Euryarchaeota. Cluster analysis or distance matrix tree construction based on the co-occurrence of genomes in COGs showed that A. pernix forms a distinct group within the archaea, although grouping with the two species of Pyrococci, indicative of similar repertoires of conserved genes, was observed. No indication of a specific relationship between Crenarchaeota and eukaryotes was obtained in these analyses. Several proteins that are conserved in Euryarchaeota and most bacteria are unexpectedly missing in A. pernix, including the entire set of de novo purine biosynthesis enzymes, the GTPase FtsZ (a key component of the bacterial and euryarchaeal cell-division machinery), and the tRNA-specific pseudouridine synthase, previously considered universal. A. pernix is represented in 48 COGs that do not contain any euryarchaeal members. Many of these proteins are TCA cycle and electron transport chain enzymes, reflecting the aerobic lifestyle of A. pernix. CONCLUSIONS: Special-purpose databases organized on the basis of phylogenetic analysis and carefully curated with respect to known and predicted protein functions provide for a significant improvement in genome annotation. A differential genome display approach helps in a systematic investigation of common and distinct features of gene repertoires and in some cases reveals unexpected connections that may be indicative of functional similarities between phylogenetically distant organisms and of lateral gene exchange.

Archaea↗

The utility of complete genome sequences in the study of pathogenic bacteria.

The availability of complete genome sequences is a revolution in the study of microorganisms. A fully annotated genome sequence provides an interactive tool for scientists and influences the approach and focus of research. In this article I discuss the impact of genome sequencing projects of bacteria. Much useful data have been obtained but the experimental methods needed to fully exploit the information continue to develop. Some of the approaches and particular applications relevant to bacteria of clinical importance are discussed.

Bacteria↗

GAIA: framework annotation of genomic sequence.

As increasing amounts of genomic sequence from many organisms become available, and as DNA sequences become a primary reagent in biologic investigations, the role of annotation as a prospective guide for laboratory experiments will expand rapidly. Here we describe a process of high-throughput, reliable annotation, called framework annotation, which is designed to provide a foundation for initial biologic characterization of previously unexamined sequence. To examine this concept in practice, we have constructed Genome Annotation and Information Analysis (GAIA), a prototype software architecture that implements several elements important for framework annotation. The center of GAIA consists of an annotation database and the associated data management subsystem that forms the software bus along which other components communicate. The schema for this database defines three principal concepts: (1) Entries, consisting of sequence and associated historical data; (2) Features, comprising information of biologic interest; and (3) Experiments, describing the evidence that supports Features. The database permits tracking of annotation results over time, as well as assessment of the reliability of particular results. New framework annotation is produced by CARTA, a set of autonomous sensors that perform automatic analyses and assert results into the annotation database. These results are available via a Web-based query interface that uses graphical Java applets as well as text-based HTML pages to display data at different levels of resolution and permit interactive exploration of annotation. We present results for initial application of framework annotation to a set of test sequences, demonstrating its effectiveness in providing a starting point for biologic investigation, and discuss ways in which the current prototype can be improved. The prototype is available for public use and comment at http://www.cbil.upenn.edu/gaia.

Amino Acid Sequence↗

Complete genome sequences of cellular life forms: glimpses of theoretical evolutionary genomics.

The availability of complete genome sequences of cellular life forms creates the opportunity to explore the functional content of the genomes and evolutionary relationships between them at a new qualitative level. With the advent of these sequences, the construction of a minimal gene set sufficient for sustaining cellular life and reconstruction of the genome of the last common ancestor of bacteria, eukaryotes, and archaea become realistic, albeit challenging, research projects. A version of the minimal gene set for modern-type cellular life derived by comparative analysis of two bacterial genomes, those of Haemophilus influenzae and Mycoplasma genitalium, consists of approximately 250 genes. A comparison of the protein sequences encoded in these genes with those of the proteins encoded in the complete yeast genome suggests that the last common ancestor of all extant life might have had an RNA genome.

Bacterial Proteins↗