Assessment of community efforts to advance network-based prediction of protein-protein interactions.

Comprehensive understanding of the human protein-protein interaction (PPI) network, aka the human interactome, can provide important insights into the molecular mechanisms of complex biological processes and diseases. Despite the remarkable experimental efforts undertaken to date to determine the structure of the human interactome, many PPIs remain unmapped. Computational approaches, especially network-based methods, can facilitate the identification of previously uncharacterized PPIs.

Integrating categorical and structural proximity in Disease Ontologies.

The purpose of the study described in this paper is to shed more light on disease similarities by analyzing the relationship between categorical proximity of diseases in human-curated ontologies and structural proximity of the related disease module (DM) in the interactome. We propose a methodology (and related algorithms) to automatically induce a hierarchical structure from proximity relations between DMs, and to compare this structure with a human-curated disease taxonomy.Clinical relevance- Disease ontologies are extensively used for diagnostic evaluation and clinical decision support but still reflect the clinical reductionist perspective.

A Network-Based Analysis of Disease Modules From a Taxonomic Perspective.

Objective: Human-curated diseaseontologies are widely used for diagnostic evaluation, treatment and data comparisons over time, and clinical decision support. The classification principles underlying these ontologies are guided by the analysis of observable pathological similarities between disorders, often based on anatomical or histological principles. Although, thanks to recent advances in molecular biology, disease ontologies are slowly changing to integrate the etiological and genetic origins of diseases, nosology still reflects this "reductionist" perspective.

Homology-dependent gene silencing in Paramecium.

Microinjection at high copy number of plasmids containing only the coding region of a gene into the Paramecium somatic macronucleus led to a marked reduction in the expression of the corresponding endogenous gene(s). The silencing effect, which is stably maintained throughout vegetative growth, has been observed for all Paramecium genes examined so far: a single-copy gene (ND7), as well as members of multigene families (centrin genes and trichocyst matrix protein genes) in which all closely related paralogous genes appeared to be affected. This phenomenon may be related to posttranscriptional gene silencing in transgenic plants and quelling in Neurospora and allows the efficient creation of specific mutant phenotypes thus providing a potentially powerful tool to study gene function in Paramecium.

Characterization of multigene families in the micronuclear genome of Paramecium tetraurelia reveals a germline specific sequence in an intron of a centrin gene.

In Paramecium, as in other ciliates, the transcriptionally active macronucleus is derived from the germline micronucleus by programmed DNA rearrangements, which include the precise excision of thousands of germline-specific sequences (internal eliminated sequences, IESs). We report the characterization of micronuclear versions of genes encoding Paramecium secretory granule proteins (trichocyst matrix proteins, TMPs) and Paramecium centrins. TMP and centrin multigene families, previously studied in the macronuclear genome, consist of genes that are co-expressed to provide mixtures of related polypeptides that co-assemble to form respectively the crystalline trichocyst matrix and the infraciliary lattice, a contractile cytoskeletal network.