title: Dynamic Pattern of HOXB9 Protein Localization during Oocyte Maturation and Early Embryonic Development in Mammals.
abstract: BACKGROUND
  We previously showed that the homeodomain transcription factor HOXB9 is expressed in mammalian oocytes and early embryos. However, a systematic and exhaustive study of the localization of the HOXB9 protein, and HOX proteins in general, during mammalian early embryonic development has so far never been performed.
  
  
  RESULTS
  The distribution of HOXB9 proteins in oocytes and the early embryo was characterized by immunofluorescence from the immature oocyte stage to the peri-gastrulation period in both the mouse and the bovine. HOXB9 was detected at all studied stages with a dynamic expression pattern. Its distribution was well conserved between the two species until the blastocyst stage and was mainly nuclear. From that stage on, trophoblastic cells always showed a strong nuclear staining, while the inner cell mass and the derived cell lines showed important dynamic variations both in staining intensity and in intra-cellular localization. Indeed, HOXB9 appeared to be progressively downregulated in epiblast cells and only reappeared after gastrulation had well progressed. The protein was also detected in the primitive endoderm and its derivatives with a distinctive presence in apical vacuoles of mouse visceral endoderm cells.
  
  
  CONCLUSIONS
  Together, these results could suggest the existence of unsuspected functions for HOXB9 during early embryonic development in mammals.
authors: Biologie Moléculaire et Cellulaire Animale (AMCB), Institut des Sciences de la Vie (ISV), Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors: Caroline
authors: C
authors: Sauvegarde
authors: Biologie Moléculaire et Cellulaire Animale (AMCB), Institut des Sciences de la Vie (ISV), Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors: Delphine
authors: D
authors: Paul
authors: Biologie Moléculaire et Cellulaire Animale (AMCB), Institut des Sciences de la Vie (ISV), Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors: Laure
authors: L
authors: Bridoux
authors: UMR BDR, INRA, ENVA, Université Paris Saclay, Jouy-en-Josas, France.
authors: Alice
authors: A
authors: Jouneau
authors: Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S1139, U767, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France.|Université Paris Descartes, Sorbonne Paris Cité, Paris, France.|PremUp Foundation, Paris, France.
authors: Séverine
authors: S
authors: Degrelle
authors: UMR BDR, INRA, ENVA, Université Paris Saclay, Jouy-en-Josas, France.
authors: Isabelle
authors: I
authors: Hue
authors: Biologie Moléculaire et Cellulaire Animale (AMCB), Institut des Sciences de la Vie (ISV), Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors: René
authors: R
authors: Rezsohazy
authors: Biologie Moléculaire et Cellulaire Animale (AMCB), Institut des Sciences de la Vie (ISV), Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors: Isabelle
authors: I
authors: Donnay
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism; D002417:Cattle; D019070:Cell Lineage / Q000235:genetics; D047108:Embryonic Development / Q000235:genetics; D004707:Endoderm / Q000378:metabolism; D005333:Fetus; D005455:Fluorescent Antibody Technique; D054262:Gastrulation / Q000235:genetics; D015870:Gene Expression; D055786:Gene Knockout Techniques; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008322:Mammals; D051379:Mice; D009865:Oocytes / Q000378:metabolism*; D009866:Oogenesis / Q000235:genetics; D021381:Protein Transport; D015053:Zygote / Q000378:metabolism
chemical_list: D018398:Homeodomain Proteins