Biomedical subjects

Ivan Moszer

Publications and source records attributed to Ivan Moszer.

3 recordsLinked to original sources

PubMed2005

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↗

PubMed2003

A revised annotation and comparative analysis of Helicobacter pylori genomes.

Huge amounts of genomic information are currently being generated. Therefore, biologists require structured, exhaustive and comparative databases. The PyloriGene database (http://genolist.pasteur.fr/PyloriGene) was developed to respond to these needs, by integrating and connecting the information generated during the sequencing of two distinct strains of Helicobacter pylori. This led to the need for a general annotation consensus, as the physical and functional annotations of the two strains differed significantly in some cases. A revised functional classification system was created to accommodate the existing data and to make it possible to classify coding sequences (CDS) into several functional categories to harmonize CDS classification. The annotation of the two complete genomes was revised in the light of new data, allowing us to reduce the percentage of hypothetical proteins from approximately 40 to 33%. This resulted in the reassignment of functions for 108 CDS (approximately 7% of all CDS). Interestingly, the functions of only approximately 13% of CDS (222 out of 1658 CDS) were annotated as a result of work done directly on H.pylori genes. Finally, comparison of the two published genomes revealed a significant amount of size variation between corresponding (orthologous) CDS. Most of these size variations were due to natural polymorphisms, although other sources of variation were identified, such as pseudogenes, new genes potentially regulated by slipped-strand mispairing mechanism, or frame-shifts. 113 of these differences were due to different start codon assignments, a common problem when constructing physical annotations.

Databases, Nucleic Acid↗

PubMed2002

SubtiList: the reference database for the Bacillus subtilis genome.

SubtiList is the reference database dedicated to the genome of Bacillus subtilis 168, the paradigm of Gram-positive endospore-forming bacteria. Developed in the framework of the B.subtilis genome project, SubtiList provides a curated dataset of DNA and protein sequences, combined with the relevant annotations and functional assignments. Information about gene functions and products is continuously updated by linking relevant bibliographic references. Recently, sequence corrections arising from both systematic verifications and submissions by individual scientists were included in the reference genome sequence. SubtiList is based on a generic relational data schema and a World Wide Web interface developed for the handling of bacterial genomes, called GenoList. The World Wide Web interface was designed to allow users to easily browse through genome data and retrieve information according to common biological queries. SubtiList also provides more elaborate tools, such as pattern searching, which are tightly connected to the overall browsing system. SubtiList is accessible at http://genolist.pasteur.fr/SubtiList/. Similar bacterial databases are accessible at http://genolist.pasteur.fr/.

Bacillus subtilis↗