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Fournier, Éric

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Centre de recherche en biologie de la reproduction, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval
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Voici les éléments 1 - 4 sur 4
  • Publication
    The gametic synapse : RNA transfer to the bovine oocyte
    (Oxford University Press, 2014-10-01) Gilbert, Isabelle; Caballero, Julieta; Tossou, Prudencio; Khandjian, Edward William; Macaulay, Angus; Richard, François J.; Barreto, Rodrigo; Clarke, Hugh James; Robert, Claude; Fournier, Éric; Sirard, Marc-André; Hyttel, P.
    Even after several decades of quiescent storage in the ovary, the female germ cell is capable of reinitiating transcription to build the reserves that are essential to support early embryonic development. In the current model of mammalian oogenesis, there exists bilateral communication between the gamete and the surrounding cells that is limited to paracrine signaling and direct transfer of small molecules via gap junctions existing at the end of the somatic cells' projections that are in contact with the oolemma. The purpose of this work was to explore the role of cumulus cell projections as a means of conductance of large molecules, including RNA, to the mammalian oocyte. By studying nascent RNA with confocal and transmission electron microscopy in combination with transcript detection, we show that the somatic cells surrounding the fully grown bovine oocyte contribute to the maternal reserves by actively transferring large cargo, including mRNA and long noncoding RNA. This occurrence was further demonstrated by the reconstruction of cumulus-oocyte complexes with transfected cumulus cells transferring a synthetic transcript. We propose selective transfer of transcripts occurs, the delivery of which is supported by a remarkable synapselike vesicular trafficking connection between the cumulus cells and the gamete. This unexpected exogenous contribution to the maternal stores offers a new perspective on the determinants of female fertility.
  • Publication
    Cumulus cell transcripts transit to the bovine oocyte in preparation for maturation
    (Society for the Study of Reproduction., 2015-11-13) Gilbert, Isabelle; Ettaoumi, Sara; Bastien, Alexandre; Gagné, Dominic; Ashkar, Fazl; Khandjian, Edward William; Macaulay, Angus; Shojaei Saadi, Habib Allah; Richard, François J.; Robert, Claude; Fournier, Éric; Sirard, Marc-André; Hyttel, P.
    So far, the characteristics of a good quality egg have been elusive, similar to the nature of the physiological, cellular, and molecular cues leading to its production both in vivo and in vitro. Current understanding highlights a strong and complex interdependence between the follicular cells and the gamete. Secreted factors induce cellular responses in the follicular cells, and direct exchange of small molecules from the cumulus cells to the oocyte through gap junctions controls meiotic arrest. Studying the interconnection between the cumulus cells and the oocyte, we previously demonstrated that the somatic cells also contribute transcripts to the gamete. Here, we show that these transcripts can be visualized moving down the transzonal projections (TZPs) to the oocyte, and that a time course analysis revealed progressive RNA accumulation in the TZPs, indicating that RNA transfer occurs before the initiation of meiosis resumption under a timetable fitting with the acquisition of developmental competence. A comparison of the identity of the nascent transcripts trafficking in the TZPs, with those in the oocyte increasing in abundance during maturation, and that are present on the oocyte's polyribosomes, revealed transcripts common to all three fractions, suggesting the use of transferred transcripts for translation. Furthermore, the removal of potential RNA trafficking by stripping the cumulus cells caused a significant reduction in maturation rates, indicating the need for the cumulus cell RNA transfer to the oocyte. These results offer a new perspective to the determinants of oocyte quality and female fertility, as well as provide insight that may eventually be used to improve in vitro maturation conditions.
  • Publication
    Meta-analysis of gene expression profiles in granulosa cells during folliculogenesis
    (Journals of Reproduction and Fertility, 2016-05-24) Khan, Daulat Raheem; Richard, François J.; Dufort, Isabelle; Fournier, Éric; Sirard, Marc-André; Singh, Jaswant
    Folliculogenesis involves coordinated profound changes in different follicular compartments and significant modifications of their gene expression patterns, particularly in granulosa cells. Huge datasets have accumulated from the analyses of granulosa cell transcriptomic signatures in predefined physiological contexts using different technological platforms. However, no comprehensive overview of folliculogenesis is available. This would require integration of datasets from numerous individual studies. A prerequisite for such integration would be the use of comparable platforms and experimental conditions. The EmbryoGENE program was created to study bovine granulosa cell transcriptomics under different physiological conditions using the same platform. Based on the data thus generated so far, we present here an interactive web interface called GranulosaIMAGE (Integrative Meta-Analysis of Gene Expression), which provides dynamic expression profiles of any gene of interest and all isoforms thereof in granulosa cells at different stages of folliculogenesis. GranulosaIMAGE features two kinds of expression profiles: gene expression kinetics during bovine folliculogenesis from small (6 mm) to pre-ovulatory follicles under different hormonal and physiological conditions and expression profiles of granulosa cells of dominant follicles from post-partum cows in different metabolic states. This article provides selected examples of expression patterns along with suggestions for users to access and generate their own patterns using GranulosaIMAGE. The possibility of analysing gene expression dynamics during the late stages of folliculogenesis in a mono-ovulatory species such as bovine should provide a new and enriched perspective on ovarian physiology.
  • Publication
    Accès libre
    A syst-OMICS approach to ensuring food safety and reducing the economic burden of salmonellosis
    (Frontiers Media S.A., 2017-06-02) Tremblay, Denise; Groleau, Gisèle.; Loignon, Stéphanie; Vincent, Caroline; Moineau, Sylvain; Colavecchio, Anna; Kukavica-Ibrulj, Iréna; Barrere, Virginie; Fliss, Ismaïl; Cadieux, Brigitte; Bekal, Sadjia; Arya, Gitanjali; Dewar, Ken; Fournier, Éric; Berry, Chrystal; Jeukens, Julie; Burnett, Elton; Emond Rheault, Jean-Guillaume; Levesque, Roger; Chapin, Travis K.; Dupont, Marie-Josée; Crouse, Alanna; Boyle, Brian; Daigle, France; Freschi, Luca; Danyluk, Michelle D.; Delaquis, Pascal J.; Doualla-Bell, Florence; Fong, Karen; Franz, Eelco; Garduno, Rafael; Gill, Alexander; Gruenheid, Samantha; Harris, Linda J.; Huang, Carol B.; Huang, Hongsheng; Johnson, Roger; Joly, Yann; Kerhoas, Maud; Kong, Nguyet; Larivière, Line; Malo, Danielle; Mottawea, Walid; Mukhopadhyay, Kakali; Nadon, Céline; Nash, John; Ngueng Feze, Ida; Ogunremi, Dele; Perets, Ann; Pilar, Ana V.; Reimer, Aleisha R.; Robertson, James; Rohde, John; Sanderson, Kenneth E.; Song, Lingqiao; Stephan, Roger; Tamber, Sandeep; Thomassin, Paul J.; Usongo, Valentine; Wang, Siyun; Weadge, Joel T.; Wiedmann, Martin; Wijnands, Lucas; Wilson, Emily D.; Wittum, Thomas; Yoshida, Catherine; Yousfi, Khadija; Zhu, Lei; Weimer, Bart C.; Goodridge, Lawrence; Cavestri, Camille
    The Salmonella Syst-OMICS consortium is sequencing 4,500 Salmonella genomes and building an analysis pipeline for the study of Salmonella genome evolution, antibiotic resistance and virulence genes. Metadata, including phenotypic as well as genomic data, for isolates of the collection are provided through the Salmonella Foodborne Syst-OMICS database (SalFoS), at Here, we present our strategy and the analysis of the first 3,377 genomes. Our data will be used to draw potential links between strains found in fresh produce, humans, animals and the environment. The ultimate goals are to understand how Salmonella evolves over time, improve the accuracy of diagnostic methods, develop control methods in the field, and identify prognostic markers for evidence-based decisions in epidemiology and surveillance.