PubMed Health⌕ Search

Biomedical subjects

Paul Stothard

Publications and source records attributed to Paul Stothard.

10 recordsLinked to original sources

BASys: a web server for automated bacterial genome annotation.

BASys (Bacterial Annotation System) is a web server that supports automated, in-depth annotation of bacterial genomic (chromosomal and plasmid) sequences. It accepts raw DNA sequence data and an optional list of gene identification information and provides extensive textual annotation and hyperlinked image output. BASys uses >30 programs to determine approximately 60 annotation subfields for each gene, including gene/protein name, GO function, COG function, possible paralogues and orthologues, molecular weight, isoelectric point, operon structure, subcellular localization, signal peptides, transmembrane regions, secondary structure, 3D structure, reactions and pathways. The depth and detail of a BASys annotation matches or exceeds that found in a standard SwissProt entry. BASys also generates colorful, clickable and fully zoomable maps of each query chromosome to permit rapid navigation and detailed visual analysis of all resulting gene annotations. The textual annotations and images that are provided by BASys can be generated in approximately 24 h for an average bacterial chromosome (5 Mb). BASys annotations may be viewed and downloaded anonymously or through a password protected access system. The BASys server and databases can also be downloaded and run locally. BASys is accessible at http://wishart.biology.ualberta.ca/basys.

Chromosomes, Bacterial↗

Identification of novel and known oocyte-specific genes using complementary DNA subtraction and microarray analysis in three different species.

The main objective of the present study was to identify novel oocyte-specific genes in three different species: bovine, mouse, and Xenopus laevis. To achieve this goal, two powerful technologies were combined: a polymerase chain reaction (PCR)-based cDNA subtraction, and cDNA microarrays. Three subtractive libraries consisting of 3456 clones were established and enriched for oocyte-specific transcripts. Sequencing analysis of the positive insert-containing clones resulted in the following classification: 53% of the clones corresponded to known cDNAs, 26% were classified as uncharacterized cDNAs, and a final 9% were classified as novel sequences. All these clones were used for cDNA microarray preparation. Results from these microarray analyses revealed that in addition to already known oocyte-specific genes, such as GDF9, BMP15, and ZP, known genes with unknown function in the oocyte were identified, such as a MLF1-interacting protein (MLF1IP), B-cell translocation gene 4 (BTG4), and phosphotyrosine-binding protein (xPTB). Furthermore, 15 novel oocyte-specific genes were validated by reverse transcription-PCR to confirm their preferential expression in the oocyte compared to somatic tissues. The results obtained in the present study confirmed that microarray analysis is a robust technique to identify true positives from the suppressive subtractive hybridization experiment. Furthermore, obtaining oocyte-specific genes from three species simultaneously allowed us to look at important genes that are conserved across species. Further characterization of these novel oocyte-specific genes will lead to a better understanding of the molecular mechanisms related to the unique functions found in the oocyte.

Animals↗

BacMap: an interactive picture atlas of annotated bacterial genomes.

BacMap is an interactive visual database containing fully labeled, zoomable and searchable chromosome maps from more than 170 bacterial (archaebacterial and eubacterial) species. It uses a recently developed visualization tool (CGView) to generate high-resolution circular genome maps from sequence feature information. Each map includes an interface that allows the image to be expanded and rotated. In the default view, identified genes are drawn to scale and colored according to coding directions. When a region of interest is expanded, gene labels are displayed. Each label is hyperlinked to a custom 'gene card' which provides several fields of information concerning the corresponding DNA and protein sequences. Each genome map is searchable via a local BLAST search and a gene name/synonym search. BacMap is freely available at http://wishart.biology.ualberta.ca/BacMap/.

Chromosome Mapping↗

Circular genome visualization and exploration using CGView.

UNLABELLED: CGView (Circular Genome Viewer) is a Java application and library for generating high-quality, zoomable maps of circular genomes. It converts XML or tab-delimited input into a graphical map (PNG, JPG or Scalable Vector Graphics format), complete with sequence features, labels, legends and footnotes. In addition to the default full view map, the program can generate a series of hyperlinked maps showing expanded views. The linked maps can be explored using any Web browser, allowing rapid genome browsing and facilitating data sharing. AVAILABILITY: CGView (the standalone application, library or applet), sample input, sample maps and documentation can be obtained from http://wishart.biology.ualberta.ca/cgview/ CONTACT: david.wishart@ualberta.ca.

Chromosome Mapping↗

PlasMapper: a web server for drawing and auto-annotating plasmid maps.

PlasMapper is a comprehensive web server that automatically generates and annotates high-quality circular plasmid maps. Taking only the plasmid/vector DNA sequence as input, PlasMapper uses sequence pattern matching and BLAST alignment to automatically identify and label common promoters, terminators, cloning sites, restriction sites, reporter genes, affinity tags, selectable marker genes, replication origins and open reading frames. PlasMapper then presents the identified features in textual form and as high-resolution, multicolored graphical output. The appearance and contents of the output can be customized in numerous ways using several supplied options. Further, PlasMapper images can be rendered in both rasterized (PNG and JPG) and vector graphics (SVG) formats to accommodate a variety of user needs or preferences. The images and textual output are of sufficient quality that they may be used directly in publications or presentations. The PlasMapper web server is freely accessible at http://wishart.biology.ualberta.ca/PlasMapper.

Chromosome Mapping↗

The CyberCell Database (CCDB): a comprehensive, self-updating, relational database to coordinate and facilitate in silico modeling of Escherichia coli.

The CyberCell Database (CCDB: http://redpoll. pharmacy.ualberta.ca/CCDB) is a comprehensive, web-accessible database designed to support and coordinate international efforts in modeling an Escherichia coli cell on a computer. The CCDB brings together both observed and derived quantitative data from numerous independent sources covering many aspects of the genomic, proteomic and metabolomic character of E.coli (strain K12). The database is self-updating but also supports 'community' annotation, and provides an extensive array of viewing, querying and search options including a powerful, easy-to-use relational data extraction system.

Computational Biology↗

Sex-determination gene and pathway evolution in nematodes.

The pathway that controls sexual fate in the nematode Caenorhabditis elegans has been well characterized at the molecular level. By identifying differences between the sex-determination mechanisms in C. elegans and other nematode species, it should be possible to understand how complex sex-determining pathways evolve. Towards this goal, orthologues of many of the C. elegans sex regulators have been isolated from other members of the genus Caenorhabditis. Rapid sequence evolution is observed in every case, but several of the orthologues appear to have conserved sex-determining roles. Thus extensive sequence divergence does not necessarily coincide with changes in pathway structure, although the same forces may contribute to both. This review summarizes recent findings and, with reference to results from other animals, offers explanations for why sex-determining genes and pathways appear to be evolving rapidly. Experimental strategies that hold promise for illuminating pathway differences between nematodes are also discussed.

Animals↗

Evolution of the PP2C family in Caenorhabditis: rapid divergence of the sex-determining protein FEM-2.

To investigate the causes and functional significance of rapid sex-determining protein evolution we compared three Caenorhabditis elegans genes encoding members of the protein phosphatase 2C (PP2C) family with their orthologs from another Caenorhabditis species (strain CB5161). One of the genes encodes FEM-2, a sex-determining protein, while the others have no known sex-determining role. FEM-2's PP2C domain was found to be more diverged than the other PP2C domains, supporting the notion that sex-determining proteins are subjected to selective pressures that allow for or cause rapid divergence. Comparison of the positions of amino acid substitutions in FEM-2 with a solved three-dimensional structure suggests that the catalytic face of the protein is highly conserved among C. elegans, CB5161, and another closely related species C. briggsae. However, the non-conserved regions of FEM-2 cannot be said to lack functional importance, since fem-2 transgenes from the other species were unable to rescue the germ-line defect caused by a C. elegans fem-2 mutation. To test whether fem-2 functions as a sex-determining gene in the other Caenorhabditis species we used RNA-mediated interference (RNAi). fem-2 (RNAi) in C. elegans and C. briggsae caused germ-line feminization, but had no noticeable effect in CB5161. Thus the function of fem-2 in CB5161 remains uncertain.

Amino Acid Sequence↗

Antigenic variation among isolates of infectious salmon anaemia virus correlates with genetic variation of the viral haemagglutinin gene.

Infectious salmon anaemia virus (ISAV), an orthomyxovirus-like virus, is an important fish pathogen in marine aquaculture. Virus neutralization of 24 ISAV isolates in the TO cell line using rabbit antisera to the whole virus and comparative sequence analysis of their haemagglutinin (HA) genes have allowed elaboration on the variation of ISAV isolates. The 24 viruses were neutralized to varying degrees, revealing two major antigenic groups, one American and one European. Sequence analysis of the HA gene also revealed two groups of viruses (genotypes) that correlated with the antigenic groupings. The two HA subtypes had nucleotide sequence identity of only < or =79.4% and amino acid sequence identity of < or =84.5% whereas, within each subtype, the sequence identities were 90.7% or higher. This grouping was also evident upon phylogenetic analysis, which revealed two distinct phylogenetic families. Between the two groups, the amino acid sequence was most variable in the C-terminal region and included deletions of 4-16 amino acids in all isolates relative to ISAV isolate RPC/NB-980 280-2. In order to view the relationships among these sequences and the HA sequences of the established orthomyxoviruses, a second phylogenetic tree was constructed which showed the ISAV sequences to be more closely related to sequences from Influenzavirus A and Influenzavirus B than to sequences from Influenzavirus C and Thogotovirus. The extensive deletions in the gene of European ISAV isolates lead us to speculate that the archetypal ISAV was probably of Canadian origin.

Amino Acid Sequence↗