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Pasquier, C.

Publications and source records attributed to Pasquier, C..

2 recordsLinked to original sources

Identification of active modules in interaction networks using node2vec network embedding

The identification of condition-specific gene sets from transcriptomic experiments is important to reveal regulatory and signaling mechanisms associated with a given cellular response. Statistical approaches using only expression data allow the identification of genes whose expression is most altered between different conditions. However, a phenotype is rarely a direct consequence of the activity of a single gene, but rather reflects the interplay of several genes to carry out certain molecular processes. Many methods have been proposed to analyze the activity of genes in light of our knowledge of their molecular interactions. However, existing methods have many limitations that make them of limited use to biologists: they detect modules that are too large, too small, or they require the users to specify a priori the size of the modules they are looking for. We propose AMINE (Active Module Identification through Network Embedding), an efficient method for the identification of active modules. Experiments carried out on artificial data sets show that the results obtained are more reliable than many available methods. Moreover, the size of the modules to be identified is not a fixed parameter of the method and does not need to be specified; rather, it adjusts according to the size of the modules to be found. The applications carried out on real datasets show that the method enables to find important genes already highlighted by approaches solely based on gene variations, but also to identify new groups of genes of high interest. In addition, AMINE method can be used as a web service on your own data (http://amine.i3s.unice.fr).

bioinformatics

SARS-CoV-2 might manipulate against its host the immunity RNAi/Dicer/Ago system

The role of the RNAi/Dicer/Ago system to degrade RNA viruses has been elusive in mammals, which prompted authors to think that interferon (IFN) synthesis is essential in this clade relegating the RNAi defense strategy against viral infection as accessory function. We explore the theoretical possibilities that RNAi triggered by SARS-CoV-2 might degrade some host transcripts in the opposite direction although this hypothesis seems counter intuitive. SARS-CoV-2 genome was therefore computational searched for exact intra pairing within the viral RNA and also hybrid exact pairing with human transcriptome over a minimum 20 bases length. Minimal segments of 20 bases length of SARS-CoV-2 RNA were found based on the theoretical matching with existing complementary strands in the human host transcriptome. Few human genes potentially annealing with SARS-CoV-2 RNA, among them mitochondrial deubiquitinase USP30, a subunit of ubiquitin protein ligase complex FBXO21 along with two long coding RNAs were retrieved. The hypothesis that viral originated RNAi might mediate degradation of messengers of the host transcriptome was corroborated by clinical observation and phylogenetic comparative analysis indicating a strong specificity of these hybrid pairing sequences for both SARS-CoV-2 and human genomes.

cell biology