title: Effects of bone morphogenic protein 4 (BMP4) and its inhibitor, Noggin, on in vitro maturation and culture of bovine preimplantation embryos.
abstract: BACKGROUND
  BMP4 is a member of the transforming growth factor beta (TGFbeta) superfamily and Noggin is a potent BMP inhibitor that exerts its function by binding to BMPs preventing interactions with its receptors. The aim of this work was to investigate the role of BMP4 and Noggin, on oocytes in vitro maturation (m experiments) and embryos in vitro development (c experiments) of bovine.
  
  
  METHODS
  For m experiments, COCs were collected from slaughterhouse ovaries and in vitro matured in TCM with 100 ng/ml of either BMP4 or Noggin. After 24 h, the nuclear stage of the oocytes was determined by staining with Hoechst 33342. In addition, RT-qPCR was performed on MII oocytes to study the relative concentration of ZAR1, GDF9, BAX, MATER and HSP70 transcripts. Treated oocytes were submitted to parthenogenic activation (PA) or in vitro fertilization (IVF) and cultured in CR2. For c experiments, non-treated matured oocytes were submitted to PA or IVF to generate embryos that were exposed to 100 ng/ml of BMP4 or Noggin in CR2 until day nine of culture. Cleavage, blastocyst and hatching rates, expression pattern of the transcription factor Oct-4 in blastocysts and embryo cell number at day two and nine post-activation or fertilization were evaluated.
  
  
  RESULTS
  We found that Noggin, as BMP4, did not affect oocyte nuclear maturation. Noggin supplementation up-regulated the expression of HSP70 and MATER genes in matured oocytes. Moreover, BMP4 during maturation increased the proportion of Oct-4 positive cells in parthenogenic embryos. On the other hand, when Noggin was added to embryo culture medium, developmental rates of parthenogenic and in vitro fertilized embryos were reduced. However, BMP4 addition decreases the development only for in vitro fertilized embryos. BMP4 and Noggin during culture reduced the proportion of Oct-4-expressing cells.
  
  
  CONCLUSIONS
  Our results show that BMP4 is implicated in bovine oocytes maturation and embryo development. Moreover, our findings demonstrate, for the first time, that a correct balance of BMP signaling is needed for proper pre-implantation development of bovine embryos.
authors.affiliation: Laboratory of Animal Biotechnology, Agriculture Faculty, University of Buenos Aires (UBA), Argentina.
authors.forename: Isabel
authors.initials: I
authors.lastname: La Rosa
authors.forename: Luiz  S A
authors.initials: L
authors.lastname: Camargo
authors.forename: Michele M
authors.initials: MM
authors.lastname: Pereira
authors.forename: Rafael
authors.initials: R
authors.lastname: Fernandez-Martin
authors.forename: Dante A
authors.initials: DA
authors.lastname: Paz
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Salamone
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000096:biosynthesis; D001755:Blastocyst / Q000187:drug effects / Q000378:metabolism; D055415:Bone Morphogenetic Protein 4 / Q000037:antagonists & inhibitors / Q000502:physiology*; D002352:Carrier Proteins / Q000502:physiology*; D002417:Cattle; D047108:Embryonic Development / Q000187:drug effects; D005307:Fertilization in Vitro; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis; D010312:Parthenogenesis / Q000502:physiology; D000099176:Noggin Protein
chemical_list: D001324:Autoantigens; D055415:Bone Morphogenetic Protein 4; D002352:Carrier Proteins; D018840:HSP70 Heat-Shock Proteins; D000099176:Noggin Protein