Vincent Hyenne, Michel Cohen-Tannoudji, Francina Langa, Celine Souilhol, Christine Petit, Bernard Maro, Silvia Cereghini, Marie-Christine Simmler, Laboratoire de Biologie du Développement (LBD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Génétique Fonctionnelle de la Souris, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Génétique des Déficits Sensoriels, Institut Pasteur [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM), Chaire Génétique et physiologie cellulaire, Collège de France (CdF (institution)), Centre d'Ingénierie génétique murine - Mouse Genetics Engineering Center (CIGM), Institut Pasteur [Paris], Sackler Faculty of Medicine, Tel Aviv University [Tel Aviv], Institut Jacques Monod (IJM (UMR_7592)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), This work was supported by research Grants R0375/38 and R0475/100 from the Ligue Contre le Cancer (BM). Vincent Hyenne was recipient of a fellowship from the Ministère de l’Education et de la Recherche Technologique (MENRT) and from the Fondation pour la Recherche Médicale (FRM). Céline Souilhol is recipient of a fellowship from the Centre National de la Recherche Scientfique (CNRS). We thank Aude Jobart (IJM/CNRS UMR 7592) for her help with confocal microscopy. We are grateful to Rémi Beau and Françoise Thouron (Centre Ingéniérie Génétique Murine/Institut Pasteur) and Mélanie Fabre (Organogenèse Précoce chez la Souris et Maladies Génétiques Associées/CNRS UMR 7622) for excellent technical support., We sincerely thank Drs. Thierry Galli and Sophie Louvet-Vallée for critical review. We are grateful to Drs. Isabelle Roux, Yvan Lallemand and Shahragim Tajbakhsh for generous support and encouragement, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Institut Pasteur [Paris] (IP)-Institut National de la Santé et de la Recherche Médicale (INSERM), Collège de France - Chaire Génétique et physiologie cellulaire, Institut Pasteur [Paris] (IP), Tel Aviv University (TAU), and Cohen-Tannoudji, Michel
International audience; Vezatin, a protein associated to adherens junctions in epithelial cells, is already expressed in mouse oocytes and during pre-implantation development. Using a floxed strategy to generate a vezatin-null allele, we show that the lack of zygotic vezatin is embryonic lethal, indicating that vezatin is an essential gene. Homozygous null embryos are able to elicit a decidual response but as early as day 6.0 post-coitum mutant implantation sites are devoid of embryonic structures. Mutant blastocysts are morphologically normal, but only half of them are able to hatch upon in vitro culture and the blastocyst outgrowths formed after 3.5 days in culture exhibit severe abnormalities, in particular disrupted intercellular adhesion and clear signs of cellular degeneration. Notably, the junctional proteins E-cadherin and beta-catenin are delocalized and not observed at the plasma membrane anymore. These in vitro observations reinforce the idea that homozygous vezatin-null mutants die at the time of implantation because of a defect in intercellular adhesion. Together these results indicate that the absence of zygotic vezatin is deleterious for the implantation process, most likely because cadherin-dependent intercellular adhesion is impaired in late blastocysts when the maternal vezatin is lost.