Transcriptome analysis of primary bovine extra-embryonic cultured cells

International audienceThe dataset described in this article pertains to the article by Hue et al. (2015) entitled "Primary bovine extra-embryonic cultured cells: A new resource for the study of in vivo peri-implanting phenotypes and mesoderm formation" [1]. In mammals, extra-embryonic tissues are essential to support not only embryo patterning but also embryo survival, especially in late implanting species. These tissues are composed of three cell types: trophoblast (bTCs), endoderm (bXECs) and mesoderm (bXMCs). Until now, it is unclear how these cells interact. In this study, we have established primary cell cultures of extra-embryonic tissues from bovine embryos collected at day-18 after artificial insemination. We used our homemade bovine 10K array (GPL7417) to analyze the gene expression profiles of these primary extra-embryonic cultured cells compared to the corresponding cells from in vivo micro-dissected embryos. Here, we described the experimental design, the isolation of bovine extra-embryonic cell types as well as the microarray expression analysis. The dataset has been deposited in Gene Expression Omnibus (GEO) (accession number GSE52967). Finally, these primary cell cultures were a powerful tool to start studying their cellular properties, and will further allow in vitro studies on cellular interactions among extra-embryonic tissues, and potentially between extra-embryonic vs embryonic tissues

Deciphering mechanisms promoting elongation in ungulates

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Towards the modelling of conceptus morphogenesis in ruminants

National audienceIn ruminants, the elongation of the conceptus is marked by an anisotropic growth of the extra- embryonic tissues prior to implantation. This has not been related so far to processes such as cell deformation or specific cell organisation and could result from oriented cell divisions within the trophoblast [Wang, CRAS, 2009]. However, since the endoderm cells that underline the trophoblast display highly anisotropic features [Flechon, Genesis, 2007] it could be that this extra-embryonic layer drives the elongation process. To test these 2 hypotheses: oriented trophoblast division and endoderm driven process, we have started analysing these cells, their divisions and their interactions to extract biological and/or biophysical parameters. Once evaluated, we could integrate them and aim at the modelling of this ruminant specific morphogenesis

Towards the modelling of conceptus morphogenesis in ruminants

In ruminants, the elongation of the conceptus is marked by an anisotropic growth of the extra- embryonic tissues prior to implantation. This has not been related so far to processes such as cell deformation or specific cell organisation and could result from oriented cell divisions within the trophoblast [Wang, CRAS, 2009]. However, since the endoderm cells that underline the trophoblast display highly anisotropic features [Flechon, Genesis, 2007] it could be that this extra-embryonic layer drives the elongation process. To test these 2 hypotheses: oriented trophoblast division and endoderm driven process, we have started analysing these cells, their divisions and their interactions to extract biological and/or biophysical parameters. Once evaluated, we could integrate them and aim at the modelling of this ruminant specific morphogenesis

Bovine primary cells as a new resource to mine extra-embryonic phenotypes in vivo

National audienc

Polarisation de la croissance trophoblastique : rôle du cytosquelette ?

L'élongation du conceptus de ruminants, qui correspond à une croissance tissulaire anisotropique, n'est liée ni à une déformation des cellules ni à une organisation particulière de l'épithélium trophoblastique, mais pourrait résulter de l'orientation préférentielle de ses plans de division [Wang, 2009]. Pour tester cette hypothèse, qui serait liée à l'endoderme sous-jacent [Fléchon, 2007], nous avons utilisé des substrats et des patrons d'adhésion prédéfinis (CYTOO) pour tester in vitro les capacités adhésives de cellules trophoblastiques fraichement isolées et comparables à leurs homologues in vivo (Degrelle, en préparation). Sur cette base, extraire des paramètres physiques pour les intégrer à un modèle multi-agents nous aiderait à modéliser l'élongation

A hybrid segmentation framework using level set method for confocal microscopy images

International audienc

Differential gene expression during trophoblast expansion in bovine embryos

National audienc

Annexin-A5 organized in 2D-network at the plasmalemma eases human trophoblast fusion OPEN

International audienceOnly a limited number of human cells can fuse to form a multinucleated syncytium. Cell fusion occurs as part of the differentiation of some cell types, including myotubes in muscle and osteoclasts in remodeling bone. In the differentiation of the human placenta, mononuclear cytotrophoblasts aggregate and fuse to form endocrinologically active, non-proliferative, multinucleated syncytia. These syncytia allow the exchange of nutrients and gases between the maternal and fetal circulation. Alteration of syncytial formation during pregnancy affects fetal growth and the outcome of the pregnancy. Here, we demonstrate the role of annexin A5 (AnxA5) in syncytial formation by cellular delivery of recombinant AnxA5 and RNA interference. By a variety of co-immunoprecipitation, immunolocalization and proximity experiments, we show that a pool of AnxA5 organizes at the inner-leaflet of the plasma membrane in the vicinity of a molecular complex that includes E-Cadherin, α-Catenin and β-Catenin, three proteins previously shown to form adherens junctions implicated in cell fusion. A combination of knockdown and reconstitution experiments with AnxA5, with or without the ability to self-assemble in 2D-arrays, demonstrate that this AnxA5 2D-network mediates E-Cadherin mobility in the plasmalemma that triggers human trophoblasts aggregation and thereby cell fusion. The cell fusion process consists of the formation of multinucleated syncytia by the mixing of cellular membrane components and cell contents from two or more cells. This complex phenomenon occurs in fertilization, placen-tation, fetal development, skeletal muscle formation and bone homeostasis 1-4. Cell fusion processes consist of three distinct stages 5 , the competence, commitment and full fusion stage. The competence stage is characterized by the loss of cellular proliferation and the differentiation into fusion-competent cells. This includes cell migration , morphological changes and secretion or response to extracellular signals such as growth factors, cytokines and hormones 5. The commitment stage describes the recognition of fusion partners, followed by the cellular adhesion and inter-cellular communication. This leads to activation, expression or assembly of the fusogenic machinery and to the synchronization of fusion-competent cells through the exchange of fusogenic signals. These two first stages are a prerequisite to promote the cell fusion with fusion pore formation between aggregated cells and the mixing of cellular content 6. Several proteins, protein macrocomplexes and cellular signaling pathways have been reported to trigger trophoblast fusion 5. Tight junction (e.g. ZO-1), adherens junction (e.g. cadherins) and gap junction (e.g. connexins) proteins have been shown to play a fundamental role during the commitment stage of trophoblast fusion 5. E-cadherin is a transmembrane protein that mediates mononuclear cell aggregation and adherens junction formation between fusion-competent cells essential for cell fusion 7. The E-cadherin extra-cellular N-terminal domain generates cellular adhesion by clustering with homotypic and heretotypic cadherins through the neighboring cell. This cellular adhesion stabilizes the cell membrane and allows polarization to the future fusion area. This triggers the clustering of fusogenic proteins or proteins initiating trophoblast fusion at the right time and the right place to the plasma membrane 5. Gap junctions are responsible for communication between adjacent cells and are composed of connexins. Gap junction channels allow the exchange of small molecules , second messengers and fusogenic signals facilitating cellular coordination, spatial compartmentalizatio