Chronic inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease, spondyloarthritis (SpA) and psoriasis cause significant morbidity and are a substantial burden for the affected individuals and the society. An important obstacle to early diagnosis and the development of more specific and effective therapies is the very limited understanding of the pathogenesis of these diseases. In the past years genome-wide association studies have identified many genes that were not known to be involved in pathogenesis, and have linked several genes in immune pathways to inflammatory diseases, indicating that the immune system plays an essential role in the pathogenesis of these diseases. The current challenge is to correlate these genetic variants with the effector mechanisms implicated in pathogenesis, to allow translation of the genetic data into relevant diagnostics and innovative treatment strategies. To meet this challenge, we have designed a clinical study that examines the immune signaling pathways, the transcriptional networks and the genotype in the same SpA patient, in order to establish a link between genetic variation, cellular phenotype and function, and pathology. This approach will advance our understanding of the pathogenic mechanisms, and identify novel and relevant diagnostic tools, therapeutic targets and biomarkers. The long-term outcome of this strategy will be the rational design of specific therapies tailored to the genotype of the patient.

The rare patients who spontaneously control HIV replication in the absence of therapy show signs of a particularly efficient T cell response. We aim at characterizing the molecular determinants underlying this efficient antiviral response. We have previously shown that CD4+ T cells from HIV controllers express T cell receptors (TCRs) of particularly high affinity for Gag peptides/ MHC II complexes. Furthermore, HIV controllers shared Gag-specific TCR clonotypes at higher frequencies than treated patients, suggesting the implication of particular TCRs in HIV control. To extend these studies, we propose to characterize the TCR repertoire and the transcriptional pattern of HIV-specific CD4+ T cells at the single cell level. We will compare HIV-specific CD4+ T cells obtained from HIV controllers included in the ANRS CO21 CODEX cohort to those from patients receiving antiretroviral therapy.

The phylogenetic position and status of “giant viruses”, formerly called NucleoCytoplasmic Large DNA viruses (NCLDV) or putative order Megavirales, are controversial. Many preliminary phylogenetic analyses have been published, but their presentations are usually highly biased by the prejudice of the authors concerning the nature of giant viruses. Our own preliminary analyses suggest that giant viruses are indeed ancient (they predate the last universal eukaryotic ancestor) and have possibly provided important functions to emerging eukaryotic cells (e.g. DNA topoisomerase activities). The number of giant virus genomes has recently dramatically increased, opening new opportunity to study their position in the “universal tree of life” and their evolutionary relationships with eukaryotes. The aim of the project is to perform an exhaustive phylogenetic analysis of all giant virus proteins with eukaryotic (archaeal/bacterial) homologues to (i) test the monophyly of giant viruses, (ii) determine their contribution to early eukaryotic evolution, iii) determine if some giant virus proteins can be useful to root the eukaryotic tree. We need the help of a bioinformatics colleague with good expertise in building phylogenetic trees from large data sets using different methods of tree construction and robustness evaluation. This work will be complemented by the systematic search for significant indels (insertion/deletion) in the alignments obtained by two members of the BMGE team (Patrick Forterre and Morgan Gaia).

Candida albicans is responsible for the majority of life-threatening fungal infections occurring in hospitalized patients and is also the most frequently isolated fungal commensal of humans. The C. albicans population includes at least 18 phylogenetic groups (or clades). Specific phenotypes can distinguish isolates within a given clade from those in other clades and yet, the relationships between C. albicans natural genetic and phenotypic diversities have not been explored in depth. We have sequenced the diploid genomes of >150 C. albicans isolates selected from a collection of commensal/clinical isolates previously used to characterize the population structure and belonging to the 12 major C. albicans clades. The aim of this project is to develop the tools necessary for an in depth analysis of these genome sequences in order to allow us ask questions about the extent of C. albicans genetic diversity, the contribution of loss-of-heterozygosity to this diversity, and the history of C. albicans population.

Across bacterial, archaeal and eukaryotic kingdoms, heat shock proteins (HSPs) are defined as a class of highly conserved chaperone proteins that are rapidly induced in response to temperature increase through dedicated heat shock transcription factors. While this transcriptional response governs cellular adaptation of fungal, plant and animal cells to thermic shock and other forms of stress, early-branching eukaryotes of the kinetoplastid order, including trypanosomatid parasites, lack classical mechanisms of transcriptional regulation and show largely constitutive expression of HSPs, thus raising important questions on the function of HSPs in the absence of stress and the regulation of their chaperone activity in response to environmental adversity. Understanding parasite-specific mechanisms of stress-response regulation is especially relevant for protozoan parasites of the genus Leishmania that are adapted for survival inside highly toxic phagolysosomes of host macrophages causing the various immuno-pathologies of leishmaniasis. To gain first insight into the role the heat shock repsonse for Leishmania differentiation and pathogenicity, we are studying the evolution and function of members of the HSP70 protein family combining bio-informatics and transgenics apporahces.

The PIBnet initiative is a joint effort by the above laboratories to modernize their activities, including collection management and microbial characterization approaches and technologies. Within this large concerted effort, a priority is to promote WGS as the major characterization approach of microbial agents for surveillance and outbreak investigation. Our ambition is to have shifted to WGS as a routine strain characterization method for epidemiological surveillance and outbreak investigation in the Institut Pasteur NRCs at the end of 2016. The target volume is 10 000 genomes a year. On the bioinformatics level, this requires implementing (1) fast data treatment tools and (2) Genotyping/classification schemes and methods to extract medically relevant information from genomic sequences (resistome, virulome).

We wish to investigate the extent of conservation and prevalence of small orfs of unknown function expressed in stationary phase of growth in Salmonella

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DNA topoisomerase IB (Topo IB) enzymes are ubiquitous in eukaryotes, where they represent the major DNA topoisomerase I activity. However, Topo IB sequences are also found in other phyla, such as archaea and bacteria, as well as viruses. Given the large amount of sequenced data available in public databases, this project aims to infer a robust Topo IB gene tree based on a representative set of homologous sequences gathered from a large taxonomic sample.

We have described recently a novel mechanism of regulation combining phase variation and attenuation of two pilus operons in Streptococcus gallolyticus . Phase variation occurs  by single-strand mispairing during replication due to the presence of repeats in the leader peptide located immediately upstream of the pilus operon. We wonder if the same mechanism is applicable to other bacterial genes.

The PIBnet initiative is a joint effort by 15 National Reference Centers (NRC), 8 Collaborative Centers of World Health Organization, the Collection de l’Institut Pasteur & Cyanobacteria collection and the CIBU to modernize their activities, including collection management and microbial characterization approaches and technologies. Within this large concerted effort, a priority is to promote whole genome sequencing (WGS) as the major characterization approach of microbial agents for surveillance and outbreak investigation.   Our ambition is to have shifted to WGS as a routine strain characterization method for epidemiological surveillance and outbreak investigation in the Institut Pasteur at the end of 2016. The target volume is 10,000 genomes a year. On the bioinformatics level, this requires implementing fast data treatment tools, databases, genotyping schemes and methods to extract medically relevant information from genomic sequences (resistome, virulome).

N/A

L'Analyses phylogénétique par séquence protéique, temporal et géographique des échantillons grippales avant et après l’épidémie de 2009.

The genome of C. tetani contains a chromosome of approximately 2,8Mb and a large size plasmid (74 kbp) harboring the tetanus-toxin gene. The genome of the strain E88 was sequenced and annotated (PNAS 2003, 100:1316-1321). We have sequenced and performed a first comparison of the genomes of three additional strains (Res Microbiol 2015, 166:326-331). Fourteen additional C. tetani strains were sequenced including historical strains (1952-1968) and recent French clinical isolates. We have the raw data obtained by Illumina sequencing. Sequence comparaison of chromosome and plasmid will be done. For this, in a first time the assembly of sequence read of each strain will be done, in a second time a comparaison of chromosome and the plasmid of these 14 strains by BLAST approach will be made. Finally, a phylogenetic tree will be generated allowing us to see the evolution of this bacteria.

Background: PLA2 is known to regulate vesicle secretion in diverse eukaryotic cells. We are interested in determining the putative role of PLA2 in secretion of apical vesicular organelles called micronemes and rhoptries in P. falciparum merozoites. PLA2 inhibitors such as 4-BPB are known to block growth of the related Apicomplexan parasite Toxoplasma gondii. There are 3 annotated PLA2 genes in the P. falciparum genome database (Pf3D70209100, PF3D71358000, PF3D70924000). We would like to analyze these putative PLA2 genes using bioinformatics to support our drug development studies.    

The first two cases in France of botulism due to Clostridium baratii type F were identified in November 2014, in the same family. Both cases required prolonged respiratory assistance. One of the cases had extremely high toxin serum levels and remained paralysed for two weeks. Investigations strongly supported the hypothesis of a common exposure during a family meal with high level contamination of the source. However, all analyses of leftover food remained negative. Clostridium baratii was isolated from stool specimens from the two patients. A second cluster of three cases of food-borne botulism due to Clostridium baratii type F occurred in France in August 2015. All cases required respiratory assistance. Consumption of a Bolognese sauce at the same restaurant was the likely source of contamination. Clostridium baratii was isolated both from stool specimens from the three patients and ground meat used to prepare the sauce. This is the second episode reported in France caused by this rare pathogen. One strain from the first cluster and four from the second one have been sequenced (Illumina technology). A complete genome of a C. baratii strain (Sullivan) isolated from adult stool in 2007 in New York is available in Genbank (chromosome: CP006905; plasmid: CP006906).

We submitted an article about the diversity of Clostridium botulinum strains based on MLST analysis. One reviewer of the article asked further study of our NGS data.

Les mutations de résistance aux traitements apparaissent sous l’effet de la sélection. Ces mutations sont transmises, les patients pouvant être infectés par des souches déjà résistantes à certains traitements. Ces mutations posent des problèmes considérables en limitant l’arsenal des traitements disponibles, pour les individus comme pour la population sur le long cours. Dans le cas du VIH, nous avons travaillé sur la transmission de ces mutations au sein de la population anglaise, et montré que la majorité de celles-ci étaient transmises par des patients naïfs ignorant leur infection (Mourad et al. AIDS 2015). La méthode employée était souvent ad-hoc et n’utilisait qu’une partie des données disponibles. L’objectif de ce projet est de mettre en place des modèles rigoureux et des méthodes efficaces d’estimation des paramètres (taux de transmission suivant les caractéristiques du donneur, taux de réversion, etc.).

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.

This project is intended to explore the novel protein interactions that are involved in the protein folding in cyanobacteria. Slr0286 was previously identified as a protein interacting with the D2 protein of photosystem 2 and affecting its functional assembly and stability in Synechocystis sp. PCC6803. The gene that encodes this protein appears to be in one operon with slr0285 in all strains where these two genes are found. This may suggest the functional relationship between the products of these genes. We would like to explore the question of whether these genes co-evolved and whether there could be an evidence of interaction between Slr0285 and Slr0286.

I would like to retrieve all HMT and HDM in Leishmania

Samples were collected in the field from infected patients admited in Ebola treatment Center of Macenta (ETC Guinea). Deep sequencing was performed in order to look for majority and minority variants. The aim of this study is to compare quasispecies of patients who survived and those who died and also to get detailed description of EBOV evolution in an ETC to identify phylogenetic clusters or transmission chain.

Entamoeba histolytica is a protozoan parasite and an amitochondriate pathogenic amoeba, which causes amoebiasis (dysentery and liver abscess) in humans. In addition to E. histolytica several species infect the human intestine although these do not cause disease and include in most of cases E. dispar and ocassionnally E. moshkovskii. A phylogenetically close Entamoeba, E. invadens infecting snails, is used as cellular model for Entamoeba cyst formation.

Supported by the National Agency for Research (ANR-10-GENM-0011) we developed a project to firstly study the transcriptional landscape of pathogenic E. histolytica. Among the results we discovered that 60% of ORFs present anti-sense RNAs (NATs) that map to the 3‘ end of genes. Their regulation is modified upon environmental changes. The regulation of NATs is basically governed by genomic sequences within the very short intragenic region of the amoeba genome. Secondly, we have started to conduct comparative genomics and transcriptomics approaches to understand phenotypic differences between Entamoeba species, in particular with respect to virulence.

Whole genome sequencing is revolutionizing the surveillance of foodborne and waterborne bacterial pathogens. The speed with which public health laboratories obtain information after the onset of symptoms and the regular sharing of this information between public health laboratories and epidemiologists are critical for the successful use of information to detect outbreaks early and to identify their source. For this purpose, this project aims at providing the most relevant bacterial genomic information in a timely-manner by integrating different validated in silico tools (core genome MLST, CRISPR, O and H molecular serotype, ....) into a single automated analysis pipeline.

Membrane fusion is an essential process in all forms of life, and fusion proteins are responsible of catalysing this reaction by forcing the two membranes against each other by undergoing a fusogenic conformational change. Viral fusion proteins are the most well studied and are classified in three different groups: class-I, with a central trimeric alpha-helical coiled coil with the fusion peptide at the N-terminal end; class-II, which are folded as three beta-sheet rich domains with an internal fusion loop; and class-III, with a trimeric alpha-helical coiled coil with an internal fusion loop at the tip of a β-sheet rich domain. Despite their totally different structures, the proteins from the three classes use the same overall fusion mechanism. The syncytins, which are class-I fusion proteins captured from a retrovirus that integrated in the germ-line of a primitive mammal more than 25 millions years ago, are responsible for the development of the placenta. Recently, orthologs to the class-II viral fusion proteins have been found in eukaryotic organisms: the epithelial fusion factor (EFF) family in nematodes, responsible for skin formation, and HAP2-GCS1 proteins, responsible for gamete fusion for fertilization in green algae, higher plants, unicellular protozoa, cnidarians, hemichordates, and arthropods. The fact that HAP2 was identified in the main branches of the eukaryotic taxa with the exception fungi, suggest that they should also be present in these organisms. In particular, HAP2 was identified in some insects but not in all of them, and has not been detected in vertebrates. This project is aimed at the detection of amino acid sequences sequences compatible with class II fusion proteins among the membrane proteins present in vertebrates and yeast

We are involved, in collboration with the WHO, in the SaMARA which aims at detecting the emergence of antimalarial drug resistance in Africa. Samples (dried blood spots) are collected from the Nantional Malaria Control Programmes in Africa during clinical efficacy studies. My group at the Institut Pasteur in collaboration with the Institut Cochin (Frédéric Ariey) tested these samples and assessed the proportion of parasites harboring SNPs or CNV associated to antimalarial drug resistance. We have previously demonstrated that mutations in the propeller dommain of a Kelch gene located on the chromosome 13 are strongly predictive of artemsinin resistance. Until last year, artemisinin resistance was confined in South east Asia. Recently, we have detected in African samples a high proportion of mutant parasites. This mutation has never been observed before in South east Asia. To perform comprenhensive genomic analysis, we have sequenced (Illumina) all mutants (=24) and paired wild type samples. Analysis of these sequences (and 400 whole genome sequences from parasites collected in Asia, Africa and America, upload on a dedicated website) should allow to: - define if the mutants have emerged locally or have spread from Asia - define the genetic background of these mutants (are specific alleles facilitated the emergence of K13 mutantions) - describe the genomic profile(s) of these mutants (especially the haplotypes associated to multidrug resistance)

In this project we study ecological diversification of Klebsiella pneumoniae and closely related species. Using comparative genomics we want to identify the pattern of genome adaptation to different environments

We tested DNMT and RNMT inhibitors on Leishmania parasites survival and would like to know which could be the potential targets.

Evaluation of the mutation rate per site and dN/dS of the genomes of 4 Yersinia enterocolitica strains isolated from the same patient during 14 years.

Paleo(meta)genomics is an emerging and rapidly growing field where most is yet to be done. In most cases, it consists in the analysis of ancient DNA high-throughput sequencing data obtained from archaeological material or historical samples, and the goal is to retrieve and interpret the genomic information from species that from the past (microbial, eukaryotic, etc.) It combines tools borrowed from different fields, such as genomics, computational biology, microbial ecology, phylogenetics, population genetics, etc. However, at the moment there are no well-established tools for the analysis of this type of data. Hence, each lab must develop custom solutions, combining existing tools or developing new ones to meet the goals of their research programs. As a recently established lab, the microbial paleogenomics unit will spend the upcoming months setting up diverse pipelines and analysis tools for the different projects that will be developed in the coming years, many of which have been already used but need to be re-written in an understandable languaje and structure.

Centrosomes are the main microtubule organizing center of eukaryotic cells with critical roles in cell division, polarity, signaling and structure. In most cells, one or both centrioles act as basal body (BB), nucleating microtubules to form cilia or flagella, sensory and motile organelles of vital importance for a wide range of biological functions. Notorious deadly diseases such as cancer, microcephaly and ciliopathies correlate with dysregulation in the number and/or structure of the centrosome/BB. Defects in centriolar proteins also impact cell division and flagellar function of parasitic protists. Notably, T. gondii can assemble flagella during its sexual cycle within the cat’s enteroepithelial tissue, a largely unattainable life stage in vitro. The state of the art of the field points at the centrosome and basal body of apicomplexan and trypanosomatid parasites as potentially rich sources of novel therapeutic targets to fight parasitic diseases. However, their molecular composition and the regulation of their biogenesis remain ill-described. Albeit a number of structural components appear to be conserved between parasitic protozoa and their vertebrate hosts, the absence of conserved homologs of regulatory components, suggests that their biogenesis is likely controlled by divergent triggers of unknown targets. Within the framework of a funded ACIP grant (076-2017), this team pursued the characterization of the centrosome composition in T. gondii, and explored the localization of newly identified principles in T. brucei. This proposal focuses on deciphering the role of the newly identified proteins in the biology of the centrosome in Toxoplasma gondii, as a model for the phylum apicomplexa, and to analyze the role of these conserved proteins in basal body biogenesis and function in Trypanosoma brucei. Based on our preliminary identification of novel centrosomal/basal body components and the powerful tools available in our model organisms, we now propose: 1. To analyze the phylogenetic distribution and functional domains of 20 novel proteins of T. gondii through bioinformatic approaches. 2. To assess the localization of these 20 proteins, and the function and cell cycle dynamics of those localized to the centrosome, in T. gondii. 3. To characterize the function of a protein complex linking the centrosome to nascent daughter cells in T. gondii. 4. To characterize the role of 3 novel T. brucei proteins homologs in basal body biology.

Finely tuned sensory systems enable bacteria to sense and respond to fluctuating environments, coordinating adaptive changes in metabolic pathways and physiological outputs. For pathogenic Leptospira, signaling pathways allow a timely expression of virulence factors during the successive steps of infection of a mammal host. As the bacteria is excreted by its host, signaling pathways enable switching the expression towards factors promoting survival in the environment. A unifying theme across bacterial species is that biofilm formation coincides with the synthesis of the cellular signaling molecule bis-(3?-5?)-cyclic dimeric guanosine monophosphate (c-di-GMP) and this feature seems to be conserved in Leptospira. Our current work shows that the c-di-GMP regulation pathway is a major regulatory network involved in biofilm formation, virulence and motility in the pathogen Leptospira interrogans. Biofilm production and virulence expression is quite variable across the leptospira genus (highly virulent species, low virulent species and saprophytes species showing increase biofilm production). We would like to explore how the c-di-GMP metabolism, and the many genes associated with its synthesis, and degradation have evolved across the leptospira genus. We believe that understanding the evolutionary relationship of the c-di-GMP metabolism genes in the Leptospira genus would help us to understand the contribution of this second messenger to pathogenesis and biofilm formation in the Leptospira genus

Severe bacterial infections are a leading cause of neonatal deaths, with low income countries (LICs) bearing the highest burden. In LICs, neonatal bacterial infections are mainly caused by Enterobacteriaceae. One important driver of unfavorable outcome in infections caused by these bacteria is multidrug resistance. Of particular concern, extended-spectrum beta-lactamase-producing enterobacteriaceae (ESBL-PE) are resistant to most penicillins and especially cephalosporins (3rd-4th generation). Enterobacteriaceae are known to colonize the digestive tract, which represents the first step for potential neonatal infections. The newborn is exposed at birth and during the first weeks of life to several possible sources of ESBL-PE acquisition, e.g. maternal, health-care facilities, and outside hospitals: parents, others relatives, food and environment. However, the routes of ESBL-PE acquisition in neonates are not well defined. Also, local environments and practices influence strongly the interactions of the infant with its environment. However, practices contributing to the transmission of ESBL-PE to neonates are not well characterized in LICs. The objectives of the project are: a better knowledge of the role of different routes of ESBL-PE transmissions to newborns in the community, and more specifically within a household, to understand local environments and practices that facilitate ESBL-PE transmission in Madagascar In Madagascar, 60 newborns and members of their households will be follow-up for one month. ESBL-PE will be characterized with last generation DNA sequencing methods. To integrate all these data globally, we will develop novel sophisticated analytical approaches combining mathematical modeling and statistics. Also, in-depth interviews will be conducted and mother-newborn pairs will be followed with a participants-observations methodology. Our study aims at identifying and quantifying the role of the different routes of transmission for newborns in the community. With a multidisciplinary approach, it should allow identifying the most acceptable interventions for local population to prevent ESBL-PE acquisition in newborns in Madagascar, where the burden of neonatal infection is huge. Partner : Institut Pasteur in Madagascar

Archaea and Bacteria have adapted multiple times independently to the gut environment, but the general mechanisms of adaptation to this environment are not very well know or it as been studied on very specific models. This project is focused on the multiple adaptations of Archaea to the gut environment, with a comparison to selected lineages of Bacteria.

Insect vectors durably transmit many important human and animal diseases. Insects are mobile, adaptable and difficult to control, which makes them efficient vehicles for disease emergence, spread and maintenance. Genomic tools have been applied to the study of vectors and vector control, and some insects such as the African malaria vector Anopheles gambiae have now become new model organisms for natural host-pathogen interactions. We study mosquito vectors of malaria and arboviruses, which generates four main kinds of large-scale data that requires dedicated bioinformatics expertise: i) functional dissection of mosquito immune signaling pathways by RNAseq transcriptome profiling to detect responses to pathogen infection and/or silencing of target genes, including mRNA as well as small and other non-coding RNAs, ii) next-gen genetic linkage mapping by deep sequencing of index-tagged phenotyped individual mosquitoes, iii) population genomic analysis by whole-genome sequencing of hundreds of individual 250Mb mosquito genomes, iv) metagenomic analysis of the mosquito microbiome and pathogen susceptibility, and of ecological metagenomic communities in field samples of mosquito vectors.

In recent years, large genome-wide association studies (GWAS) have been successful in identifying thousands of significant genetic associations for multiple traits and diseases1. In the course of this endeavor, sample size has proven to be the key factor for identifying new variants. For example, GWAS of body mass index (BMI), now including up to 350,000 individuals from more than 100 cohorts, have been able to identify genetic variant that explain as low as 0.02% of BMI variance2. While standard approaches for detecting new genetic variants associated with traits and diseases will go on as sample size increases, multivariate analyses have been proposed as an alternative strategy for both improving detection of new variants and exploring the multidimensional components of complex traits and diseases. Intuitively, multivariate analysis can be used to improve detection of variants displaying a pleiotropic effect3 by accumulating moderate evidence of association across multiple traits and diseases. Several recent examples have been published about not only GWAS hit overlap across related traits4, but also of genome-wide shared genetic effect5. Multivariate analyses of GWAS have also proven useful to understand shared genetics between diseases5, and potential causal relationship between phenotypes using Mendelian randomization (MR)6. Importantly, most of existing multivariate methods are based on GWAS summary statistics, while approaches based on individual-level data have been seldom considered because of major practical and ethical issues. In the continuity of ongoing work on multi-phenotype analysis (Aschard et al 20147, Aschard et al 20158), we developed an effective and robust multivariate approach of GWAS summary statistics that addresses the major barriers of existing approaches, i.e. the presence of correlation between studies that would exists when GWAS analyzed share sample9-16. Our approach consists in a robust omnibus multivariate test of GWAS summary statis

Background: Dyslexia is characterized by difficulty with learning to read fluently and with accurate comprehension despite normal intelligence. It affects 5–10% of school-age children. Familial studies repeatedly showed that first-degree relatives of affected individuals have a 30–50% risk of developing the disorder. Twin studies showed that heritability was approximately 50% with a higher concordance rate for monozygotic twins compared to dizygotic twins. Although genetic factors contribute to dyslexia, very little is known on the genes associated with the condition. Preliminary data: Our project consists in the complementary analysis of (i) a cohort of 209 patients with dyslexia, 89 relatives and 95 very well phenotyped controls and (ii) an extended pedigree (Nantaise family) with 12 members diagnosed with dyslexia in three generations. For all the individuals of the project, we genotyped >600K SNPs in order to detect SNP association and copy-number variants (CNVs). For the extended pedigree, we also used linkage analysis and whole genome sequence (WGS). Our preliminary results indicate that a single region on chromosome 7q36 is segregating with dyslexia in the Nantaise family. The region is located within CNTNAP2, a gene previously proposed as a susceptibility gene, but without formal proof of its association. The WGS data of three affected and three unaffected individuals of the pedigree was performed to detect all the variants in the linkage region. Project: We proposed to use this unique resource in France to characterize the genetic profile of patients with dyslexia. We will (i) detect the CNVs present in the patients and (ii) detect the variants in the linkage region.

Autism Spectrum Disorders (ASD) are heterogeneous neurodevelopmental disorders with a complex genetic architecture. They are characterized by impaired social communication, stereotyped behaviors and restricted interests and are frequently associated with comorbidities such as intellectual disability, epilepsy and severe sleep disorders. Hyperserotonemia and low melatonin levels are among the most replicated endophenotypes reported in ASD, but the genetic causes of such alterations remain largely unknown. Based on the biochemical profile of 717 individuals including 213 children with ASD, 128 unaffected siblings and 376 parents and other relatives, we aim to estimate the heritability of five quantitative traits associated with the melatonin synthesis pathway: whole-blood serotonin, platelet N-acetylserotonin (NAS) and plasma melatonin levels, as well as the two enzymes AANAT and ASMT activity measured in platelets.

The project aims at developing (1) a database dedicated to the storage and statistical analysis of Collaborative Cross based data and (2) implement genetic analysis tools based on rqtl2 for the identification of QTL on this data.

Complex chronic diseases are caused by the accumulation of genetic, microbial and lifestyle factors. The number and complexity of such factors makes prediction of pathogenesis and therapy particularly difficult. Although a single factor is rarely sufficient to trigger pathology, genetic and environmental factors have so far been studied in isolation. Nevertheless, a substantial number of genetic variants have been associated with disease risk and the concomitant lifestyle shift and excessive hygiene are thought to contribute to the increased incidence in inflammatory diseases in industrialized countries. Moreover, clinical and experimental observations suggest a strong impact of gut microbiota on susceptibility to inflammatory diseases. The aim of 3D PATH is to explore the multiplicity and complexity of genetic, microbial and lifestyle factors associated with vulnerability to inflammatory pathology, using mice of the Collaborative Cross (CC), that model human genetic variability. Quantitative trait loci analyses, as well as integrative data analyses on metabolic and inflammatory outcomes will reveal new genetic variants and combinations of variants associated with disease susceptibility, and whether alterations of the gut microbiota in genetically susceptible mouse strains can trigger the phenotype. Moreover, the longitudinal design of experiments will allow us to identify early biomarkers that predict the pathology later in life. In a second step, validation of the identified risk factor combinations and exploration of the underlying molecular mechanisms will be performed taking advantage of the mouse model.

Comparison of Microsatellites and Multi Locus Sequences Typing approaches. Fungi: Pneumocytis jirovecii

The highest global malaria prevalence is in Africa, where the most important vectors are members of the Anopheles gambiae species complex. We generated a large curated panel of infected wild Anopheles gambiae mosquitoes in West Africa to analyze for association of genetic variants with susceptibility to the human malaria parasite Plasmodium falciparum.

Enhancers are cis-regulatory elements that control developmental and spatial gene expression in eukaryotes. Enhancers have been little studied in mosquitoes, including the Anopheles vectors of malaria.

Bacteria exposed to bacteriophages deploy several defence systems that we wished to identify by genomes sequencing of bacteriophage-resistant isolates

Complex chronic diseases such as type 1 and 2 diabetes are caused by the accumulation of genetic, microbial and lifestyle factors. The number and complexity of such factors makes prediction of pathogenesis and therapy particularly difficult. Although a single factor is rarely sufficient to trigger pathology, genetic and environmental factors have so far been studied in isolation. Nevertheless, a substantial number of genetic variants have been associated with disease risk and the concomitant lifestyle shift and excessive hygiene are thought to contribute to the increased incidence in inflammatory diseases in industrialized countries. Moreover, clinical and experimental observations suggest a strong impact of gut microbiota on susceptibility to inflammatory diseases. The aim of 3DPATH is to explore the multiplicity and complexity of genetic, microbial and lifestyle factors associated with vulnerability to inflammatory pathology, with a particular focus on type 1 and 2 diabetes, using mice of the Collaborative Cross (CC), that model human genetic variability. Quantitative trait loci analyses, as well as integrative data analyses on metabolic and inflammatory outcomes will reveal new genetic variants and combinations of variants associated with disease susceptibility, and whether alterations of the gut microbiota in genetically susceptible mouse strains can trigger the phenotype. Moreover, the longitudinal design of experiments will allow us to identify early biomarkers that predict the pathology later in life. In a second step, validation of the identified risk factor combinations and exploration of the underlying molecular mechanisms will be performed taking advantage of the mouse model.

New mouse genetic reference populations obtained from 8 distinct founder strains, including 3 wild-derived strains, have been developped since the 2000s and are now available. These populations captured around 95% of the existing murine genetic diversity and constitute a better model than standard inbred laboratory mouse strains. These populations constitute tools to identify new phenotypes and to map the causative genetic variants (QTL mapping) behind these phenotypes. These populations include : i) Collaborative Cross (CC) inbred strains; ii) Recombinant inbred between CCs (CC-RIXs) and iii) Diversity Outbred. These populations are specifically used in the Mouse Genetics Laboratory to identify new variants involved in host susceptiblity differences to pathogens.

Insect vectors durably transmit many important human and animal diseases. Insects are mobile, adaptable and difficult to control, which makes them efficient vehicles for disease emergence, spread and maintenance. Genomic tools have been applied to the study of vectors and vector control, and some insects such as the African malaria vector Anopheles gambiae have now become new model organisms for natural host-pathogen interactions. We study mosquito vectors of malaria and arboviruses, which generates four main kinds of large-scale data that requires dedicated bioinformatics expertise: i) functional dissection of mosquito immune signaling pathways by RNAseq transcriptome profiling to detect responses to pathogen infection and/or silencing of target genes, including mRNA as well as small and other non-coding RNAs, ii) next-gen genetic linkage mapping by deep sequencing of index-tagged phenotyped individual mosquitoes, iii) population genomic analysis by whole-genome sequencing of hundreds of individual 250Mb mosquito genomes, iv) metagenomic analysis of the mosquito microbiome and pathogen susceptibility, and of ecological metagenomic communities in field samples of mosquito vectors.

We are involved, in collboration with the WHO, in the SaMARA which aims at detecting the emergence of antimalarial drug resistance in Africa. Samples (dried blood spots) are collected from the Nantional Malaria Control Programmes in Africa during clinical efficacy studies. My group at the Institut Pasteur in collaboration with the Institut Cochin (Frédéric Ariey) tested these samples and assessed the proportion of parasites harboring SNPs or CNV associated to antimalarial drug resistance. We have previously demonstrated that mutations in the propeller dommain of a Kelch gene located on the chromosome 13 are strongly predictive of artemsinin resistance. Until last year, artemisinin resistance was confined in South east Asia. Recently, we have detected in African samples a high proportion of mutant parasites. This mutation has never been observed before in South east Asia. To perform comprenhensive genomic analysis, we have sequenced (Illumina) all mutants (=24) and paired wild type samples. Analysis of these sequences (and 400 whole genome sequences from parasites collected in Asia, Africa and America, upload on a dedicated website) should allow to: - define if the mutants have emerged locally or have spread from Asia - define the genetic background of these mutants (are specific alleles facilitated the emergence of K13 mutantions) - describe the genomic profile(s) of these mutants (especially the haplotypes associated to multidrug resistance)

Comparison of Microsatellites and Multi Locus Sequences Typing approaches. Fungi: Pneumocytis jirovecii

In this project, we aim to identify P. vivax ligands involved in host cell invasion and understand how P. vivax has gained the capacity to infect reticulocytes from Duffy-negative individuals. Our strategy will be based on a 2-step approach by taking full advantage of next-generation sequencing and functional biological analysis (including in vitro invasion assays and infection in humanized mice) and by availing our access to P. vivax isolates from both Duffy-negative and Duffy-positive vivax malaria patients in Madagascar. This strategy should explore and charactere the full repertoire of parasite ligands involved in invasion of human reticulocytes in Malagasy malaria endemic settings where two human populations with distinct Duffy blood group phenotypes (Duffy-negative and Duffy-positive) are frequently exposed to P. vivax. The main objectives of this project are to uncover the molecular basis for the ability of P. vivax to infect reticulocytes from Duffy-positive and Duffy-negative individuals by identifying and defining the role of parasite ligands (including erythrocyte binding proteins (PvEBPs) and reticulocyte binding proteins (PvRBPs)) in mediating invasion and explore the feasibility of targeting combinations of P. vivax invasion related proteins with antibodies to block invasion with high efficiency.