Expertise

Hub members Have many expertise, covering most of the fields in bioinformatics and biostatistics. You'll find below a non-exhaustive list of these expertise

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Searched keyword : Fungi

Related people (5)

Thomas BIGOT

Group : GIPHY - Embedded : Biology of Infection

I joined the C3BI Hub in 2016 after a curriculum widely dedicated to Bioinformatics studies, and more precisely to Phylogeny and Evolution, topics of my PhD thesis. At Institut Pasteur, I am involved in projects dealing with sequences homology : alignments, hmm profiles, making homologous family databases, kmers signatures. I am also a developer (Python / C++) with a solid interest in optimization as well as in developing usable tools for final user such as automated pipeline for metagenomics sequence analysis. I’m currently embedded in Marc Eloit’s team (80% of my work time). My main task in this team is to develop strategies to identify, in their metagenomics samples, new pathogens, or new combination pathogen / symptoms. The rest of my time, I manage small projects and participate to the Hub life. I am currently experimenting with functional programming (for now, using Python) and its applicability to bioinformatics issues.


Keywords
AlgorithmicsScientific computingSofware development and engineeringParallel computingGraph theory and analysis
Organisms
BacteriaFungiVirus
Projects (7)

Anđela DAVIDOVIĆ

Group : SABER - Embedded :

I have a joint MSc degree in Mathematical Modelling from three European universities: University of L’Aquila (Italy), University of Nice-Sophia Antipolis (France) and Autonomous University of Barcelona (Spain). I also hold a PhD degree in Applied Mathematics and Scientific Computing from University of Bordeaux, France. I have done my PhD and one year of post-doc at INRIA Bordeaux Sud-Ouest, and partially at IHU-Liryc. During this time I studied how electrical signals propagate through the cardiac tissue under certain diseased conditions. My model of interest was the bidomain model, which is a system of partial differential equations that takes into account physiological properties of the cardiac cells and the spatial organization of the cardiac tissue. I worked on the mathematical multiscale analysis and numerical simulations of the problem to understand how structural changes of the tissue affect the propagation of the signal on the heart level. I collaborated with biologists and engineers of the IHU-Liryc to apply my model on a rat heart using high-resolution MRI data. For this I also worked on image analysis and image processing. I’ve joined the Institute Pasteur in February 2018 as a member of the HUB in Bioinformatics and Biostatistics. Currently I am working on stochastic mathematical modeling and inference for systems biology, gene expression, RNA transcription, etc.


Keywords
ModelingScientific computingApplication of mathematics in sciencesGraphics and Image Processing
Organisms
BacteriaFungiInsect or arthropodEscherichia coliSaccharomyces cerevisiaeFly
Projects (2)

Rachel LEGENDRE

Group : PLATEFORM - Detached : Biomics

Rachel Legendre is a bioinformatics engineer. She completed her master degree in apprenticeship for two years at INRA in Jouy-en-Josas in the Genetic Animal department. She was involved in a project aiming at the detection and the expression analysis of micro-RNA involved in an equine disease. In 2012, she joined the Genomic, Structure and Translation Team at Paris-Sud (Paris XI) university. She worked principally on Ribosome Profiling data analysis, a new technique that allows to identify the position of the ribosome on the mRNA at the nucleotide level. Since November 2015, she joined the Bioinformatics and Biostatistics HUB at Pasteur Institute and she’s detached to the Biomics Pole in C2RT, where she is in charge of the bioinformatics analyses for transcriptomics and epigenomics projects. She’s also involved in Long Reads (PacBio and Nanopore) developments with other bioinformaticians of Biomics Pole.


Keywords
AlgorithmicsChIP-seqEpigenomicsNon coding RNATranscriptomicsGenome analysisProgram developmentScientific computingSofware development and engineeringIllumina HiSeqRead mappingSequencingWorkflow and pipeline developmentChromatin accessibility assaysPac BioRibosome profiling
Organisms
BacteriaFungiParasiteHumanInsect or arthropodOther animal
Projects (9)

Christophe MALABAT

Group : HEAD - Hub Core

After a PhD in biochemistry of the rapeseed proteins, during which I developed my first automated scripts for handling data processing and analysis, I join Danone research facility center for developing multivariate models for the prediction of milk protein composition using infrared spectrometry.
As I was already developing my own informatics tools, I decided to join the course of informatic for biology of the Institut Pasteur in 2007. At the end of the course I was recruited by the Institute and integrate the unit of “génétique des interactions macromoléculaires” of Alain Jacquier. Within this group, I learn to handle sequencing data and I developed processing and analysis tools using python and R. I also create a genome browser and database system for storing, retrieving and visualizing microarray data. After 8 years within the Alain Jacquier’s lab, I join the Hub of bioinformatics and biostatistics as co-head of the team.


Keywords
ClusteringData managementSequence analysisTranscriptomicsWeb developmentDatabaseGenome analysisProgram developmentScientific computingExploratory data analysisData and text miningIllumina HiSeqRead mappingLIMSIllumina MiSeqHigh Throughput ScreeningMultidimensional data analysisWorkflow and pipeline developmentRibosome profilingMotifs and patterns detection
Organisms

Projects (9)

Related projects (27)

Genome-wide replication lanscape of Candida glabrata

Background: The opportunistic pathogen Candida glabrata is a member of the Saccharomycetaceae yeasts. Like its close relative Saccharomyces cerevisiae, it underwent a whole-genome duplication followed by an extensive loss of genes. Its genome contains a large number of very long tandem repeats, called Megasatellites. In order to determine the whole replication program of C. glabrata genome and its general chromosomal organization, we used deep-sequencing and Chromosome Conformation Capture (3C) experiments. Results: We identified 253 replication fork origins, genomewide. Centromeres, HML and HMR loci and most histone genes are replicated early, whereas natural chromosomal breakpoints are located in late replicating regions. In addition, 275 Autonomously Replicating Sequences (ARS) were identified during ARS-capture experiments, and their relative fitness was determined during growth competition. Analysis of ARSs allowed to identify a 17 bp consensus, similar to the S. cerevisiae ARS Consensus Sequence (ACS) but slightly more constrained. Megasatellites are not in close proximity to replication origins or termini. Using chromosome conformation capture, we also show that early origins tend to cluster whereas non-subtelomeric megasatellites do not cluster in the yeast nucleus. Conclusions: Despite a shorter cell cycle, the C. glabrata replication program shares unexpected striking similarities to S. cerevisiae, in spite of their large evolutionary distance and the presence of highly repetitive large tandem repeats in C. glabrata. No correlation could be found between the replication program and megasatellites, suggesting that their formation and propagation might not be directly caused by replication fork initiation or termination.



Project status : Closed

Influence of chromatin dynamics on genomic stability during replication

Genomic DNA is hierarchically packed within the living cells and genome duplication requires the concerted effort of many thousands of individual replication units. As such, to ensure the integrity of transmission of the genetic information, both eukaryotes and prokaryotes have evolved sophisticated mechanisms to monitor DNA replication. Some of these mechanisms aim to maintain both a temporal and a spatial organization of the replication program, leading to multiple replication time regions and the compartmentalization into replication foci, subnuclear sites which accumulate numerous DNA replication factors. It should be noted that Saccharomyces cerevisiae represents an exception to the standard eukaryotic strategy for genome duplication. Similar to bacteria, S. cerevisiae possess well-defined replication origin sequences that can fire at a very efficient rate during S phase, leading to a very homogenous pattern of DNA replication. A common mo del suggests that, once replication starts dynamic events take place since co-regulated replication forks, having similar replication timing, cluster within a discrete number of foci that show distinct patterns of nuclear localization over the S-phase. Once initiated, the DNA synthesis might be compromised if the replication fork encounters an RFB (Replication Fork Barrier) such as DNA lesions, tightly bound protein-DNA complexes etc. The RFBs are considered a potential source of genetic instability and may lead to many chromosomal rearrangements. As a consequence, eukaryotes employ a complex DNA damage response against RFBs, which aims to maintain the stability of the stalled forks and provides the time required to repair and resume replication. Recent observations suggest that the non-random organization of the nucleus affects where repair occurs. The aim of this project is to reach a better understanding of the influence of the nuclear spatial architecture and organization at replication fork blocks.



Project status : Closed

Mise a disposition d'un(e) bioinformaticien(ne) du hub pour les analyses bioinformatiques du transcriptome et de l epigenome

La PF Transcriptome et Epigenome développe des projets de séquençage à haut débit (collaboration et service) avec des équipes du Campus. Ceux-ci couvrent l'ensemble des thématiques du campus ainsi qu'une large gamme d'organismes (des virus aux mammifères). La plate-forme exerce des activités de biologie humide (construction des librairies et séquençage) et de biologie sèche (analyse bioinformatiques et statistiques). La personne mise a disposition interagira étroitement avec les autres bioinformaticiens du pôle BioMics et du Hub. Ses activités concerneront notamment: - La participation à la conception et à la mise en place des projets avec les équipes demandeuses, la prise en charge des analyses et le reporting aux utilisateurs - La mise en place d'un workflow d'analyse bioinformatique des données de transcriptome /épigénome en étroite collaboration avec le C3BI, la DSI et les autres bioinformaticiens du pole. Ce workflow permettra le contrôle qualité des données, leur prétraitement, le mapping des séquences sur les génomes/transcriptomes de réference, et le comptage des reads pour les différents éléments de l'annotation - L'adaptation du workflow d'analyse aux questions biologiques et aux organismes étudiés dans le cadre des activités de la PF - L'activité de veille technologique et bibliographique (test et validation de nouveaux outils d'analyse, updates d'outils existants...) - La mise en place et le développement d'outils d'analyse adaptés aux futurs projets de la PF: single cell RNAseq, métatranscriptome, ChIPseq, analyse des isoformes de splicing.. Ceci se fera notamment via la réalisation d'analyses dédiées avec certains utilisateurs. Les outils mis en place et validés dans ce cadre seront ensuite utilisés pour l'ensemble des projets. - L'activité de communication et de formation (participation aux réunions du consortium France Génomique,formation permanente à l' Institut Pasteur… - la participation a d autres projets du Pole BioMics (selon disponibilité) Bernd Jagla, qui était le bioinformaticien de la plateforme a rejoint le Hub au 1er janvier 2016. Rachel Legendre est mise a disposition depuis le 2 novembre 2015 et remplace Bernd Jagla. Je souhaite que Rachel Legendre soit mise à disposition de la plateforme pour une durée d'au moins 2 ans.



Project status : In Progress

Deciphering dormancy in Cryptocococcus neoformans



Project status : Closed

Massive amplification at an unselected locus accompanies complex chromosomal rearrangements in yeast



Project status : Closed

Interactions and dynamics of fungal and bacterial microbiome in healthy people



Project status : Awaiting Publication

Deciphering dormancy in Cryptocococcus neoformans



Project status : Awaiting Publication

Identification of new or unexpected pathogens, including viruses, bacteria, fungi and parasites associated with acute or progressive diseases

Microbial discovery remains a challenging task for which there are a lot of unmet medical and public health needs. Deep sequencing has profoundly modified this field, which can be summarized in two questions : i) which pathogens or association of pathogens are associated with diseases of unknown etiology and ii) among microbes infecting animal (including arthropod) reservoirs, which ones are able to infect large vertebrates, including humans. We are currently addressing these two questions and our current request comes with the willingness for Institut Pasteur to increase its contribution and visibility of this thematic, in particular in relation with hospitals and the Institut Pasteur International network (IPIN).  We expect to identify new microbes associated with human diseases, and this is expected to pave the way for basic research programs focusing on virulence mechanisms and host specificity, and will also lead to phylogenetic and epidemiological studies (frequency of host infection, mode of transmission etc...), as well as the development of improved diagnostic tests for human infections. Our objective is also to contribute to the efforts of Institut Pasteur in the field of infectious diseases, by building a pipeline, from sample to microbial identification, able to manage large cohorts of samples. This project is currently supported by the LABEX IBEID and the CITECH, and critically requires a bioIT support, justifying this application. Partners include different hospitals including Necker-Enfants malades University Hospital regarding patients with progressive disease, different IPIN laboratories, as well as INRA and CIRAD regarding animal/arthropod reservoirs.



Project status : In Progress

Identification of Tac4 mRNA targets

We are interested in the cytoplasmic quality control of gene expression and more especially into the behavior of aberrant peptides which could be generated from non-conform translation events. We are now investigating the role of a Saccharomyces cerevisiae RNA helicase protein that we named Tac4 (for Translation associated Component 4). We showed that this protein is involved in translation. We demonstrated, by sucrose gradient and affinity purification that Tac4 interacts with the ribosome. A first UV cross-linking and cDNA analysis (CRAC) experiment clearly revealed that Tac4 interacts with the 18S rRNA of the 40S ribosomal subunit and we precisely defined the crosslink point. These preliminary results also suggested an enrichment of the 3’-end regions of mRNAs. This implies that Tac4 could not only interact with the small ribosomal subunit but also directly with mRNA. Tac4 is conserved through the evolution and its mammalian homologue is involved in initiation of translation. Therefore, we thought that Tac4 could be associated with the 5’-end rather than with the 3’-end. However, a recent paper from the Rachel Green’s lab showed that translation reinitiation into the 3’-UTR region may occurs when translation termination is affected (Young et al., Cell 2015). The factors and molecular mechanisms implicated in these events are not known. Altogether, our preliminary results suggest that Tac4 is an excellent candidate participating to the unwinding of RNA structure or to the release of some RNA-binding proteins into the 3’-end mRNA. We now would like to 1) confirm that Tac4 preferentially interacts with the 3’-end of mRNA, 2) determine whether Tac4 interacts with a region upstream the Stop codon or in the 3’-UTR of the mRNA, 3) identify the mRNA targets to determine whether Tac4 could have a general role in translation or could only be involved in translation of some specific mRNA.



Project status : In Progress

Tac4, a new RNA helicase involved in translation control?

We are interested in the cytoplasmic quality control of gene expression and more especially into the behavior of aberrant peptides which could be generated from non-conform translation events. We are now investigating the role of a Saccharomyces cerevisiae RNA helicase protein that we named Tac4 (for Translation Associated Component 4). We showed that this protein is involved in translation. We demonstrated, by sucrose gradient and affinity purification that Tac4 interacts with the ribosome. A first UV cross-linking and cDNA analysis (CRAC) experiment clearly revealed that Tac4 interacts with the 18S rRNA of the 40S ribosomal subunit and we precisely defined the crosslink point. These preliminary results also suggested an enrichment of the 3’-end regions of mRNAs. This implies that Tac4 could not only interact with the small ribosomal subunit but also directly with mRNA. Tac4 is conserved through the evolution and its mammalian homologue is involved in initiation of translation. Therefore, we thought that Tac4 could be associated with the 5’-end rather than with the 3’-end. However, recent data showed that translation reinitiation into the 3’-UTR region may occurs when translation termination is affected. The factors and molecular mechanisms implicated in these events are not known. Altogether, our preliminary results suggest that Tac4 is an excellent candidate participating to the unwinding of RNA structure or to the release of some RNA-binding proteins into the 3’-end mRNA. We now would like to 1) confirm that Tac4 preferentially interacts with the 3’-end of mRNA, 2) determine whether Tac4 interacts with a region upstream the Stop codon or in the 3’-UTR of the mRNA, 3) determine whether Tac4 could also interact with other mRNA region, such as the 5'-UTR region, 4) identify the mRNA targets to determine whether Tac4 could have a general role in translation or could only be involved in tra



Project status : In Progress

Modeling mitochondrial metabolism dormant Cryptococcus neoformans

Cryptococcus neoformans is a ubiquitous yeast present in the environment that is able to interact closely with numerous organisms including amoeba, paramecium or nematodes. The interaction with these organisms shaped its virulence with acquisition of infectious properties as a consequence especially in mammals . The ability to survive nutrient starvation, oxidative stress, desiccation, both in the environment and during infection, indicates a high level of physiological and metabolic plasticity of the yeast. In humans, after primary infection during childhood, the yeast is able to survive within the host for years before reactivation upon immunosuppression, leading to a life threatening  disseminated fungal infection. This phenomenon, called dormancy / quiescence is one of the main biological features of this fungus in relation with disease's pathogenesis. It is well known in bacteria (tuberculosis), parasites (Plasmodium, Toxoplasma). In C. neoformans, dormancy has only been demonstrated epidemiologically in our laboratory but not experimentally so far. We developed an assay where yeasts cells exhibiting characteristics of potentially dormant cells were generated. Indeed, dormant cells are characterized by a low metabolic activity sometimes undetectable under normal laboratory conditions, altered growth capacity, and the ability to resuscitate upon adequate stimulus. Dormant cells are known to have increased mitochondrial masse and activity justifying a screening strategy of a collection of KO mutants for mitochondrial proteins. In parallel the whole proteome, transcriptome and secretome will be obtain with the ambition to correlate these parameters. Our current project aims at exploring the metabolism of the dormant yeast to have a comprehensive picture of the pathways that are required for the maintenance of dormancy and fo exit from dormancy.  



Project status : In Progress