title: Fetal-maternal interactions in the synepitheliochorial placenta using the eGFP cloned cattle model.
abstract: BACKGROUND
  To investigate mechanisms of fetal-maternal cell interactions in the bovine placenta, we developed a model of transgenic enhanced Green Fluorescent Protein (t-eGFP) expressing bovine embryos produced by nuclear transfer (NT) to assess the distribution of fetal-derived products in the bovine placenta. In addition, we searched for male specific DNA in the blood of females carrying in vitro produced male embryos. Our hypothesis is that the bovine placenta is more permeable to fetal-derived products than described elsewhere.
  
  
  RESULTS
  Samples of placentomes, chorion, endometrium, maternal peripheral blood leukocytes and blood plasma were collected during early gestation and processed for nested-PCR for eGFP and testis-specific Y-encoded protein (TSPY), western blotting and immunohistochemistry for eGFP detection, as well as transmission electron microscopy to verify the level of interaction between maternal and fetal cells. TSPY and eGFP DNA were present in the blood of cows carrying male pregnancies at day 60 of pregnancy. Protein and mRNA of eGFP were observed in the trophoblast and uterine tissues. In the placentomes, the protein expression was weak in the syncytial regions, but intense in neighboring cells on both sides of the fetal-maternal interface. Ultrastructurally, our samples from t-eGFP expressing NT pregnancies showed to be normal, such as the presence of interdigitating structures between fetal and maternal cells. In addition, channels-like structures were present in the trophoblast cells.
  
  
  CONCLUSIONS
  Data suggested that there is a delivery of fetal contents to the maternal system on both systemic and local levels that involved nuclear acids and proteins. It not clear the mechanisms involved in the transfer of fetal-derived molecules to the maternal system. This delivery may occur through nonclassical protein secretion; throughout transtrophoblastic-like channels and/or by apoptotic processes previously described. In conclusion, the bovine synepitheliochorial placenta displays an intimate fetal-maternal interaction, similar to other placental types for instance human and mouse.
authors.affiliation: University Estadual Paulista, Campus of Dracena, Dracena, Brazil.
authors.forename: Flavia Thomaz Verechia
authors.initials: FT
authors.lastname: Pereira
authors.forename: Lilian J
authors.initials: LJ
authors.lastname: Oliveira
authors.forename: Rodrigo da Silva Nunes
authors.initials: Rda S
authors.lastname: Barreto
authors.forename: Andrea
authors.initials: A
authors.lastname: Mess
authors.forename: Felipe
authors.initials: F
authors.lastname: Perecin
authors.forename: Fabiana Fernandes
authors.initials: FF
authors.lastname: Bressan
authors.forename: Ligia Garcia
authors.initials: LG
authors.lastname: Mesquita
authors.forename: Maria Angelica
authors.initials: MA
authors.lastname: Miglino
authors.forename: José RodrigoValim
authors.initials: JR
authors.lastname: Pimentel
authors.forename: Paulo
authors.initials: P
authors.lastname: Fantinato Neto
authors.forename: Flávio Vieira
authors.initials: FV
authors.lastname: Meirelles
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002417:Cattle; D002823:Chorion / Q000378:metabolism*; D019976:Cloning, Organism; D004247:DNA / Q000378:metabolism; D004622:Embryo, Mammalian / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism*; D005260:Female; D005333:Fetus / Q000378:metabolism / Q000648:ultrastructure; D049452:Green Fluorescent Proteins / Q000378:metabolism*; D006801:Humans; D008297:Male; D008431:Maternal-Fetal Exchange; D051379:Mice; D023421:Models, Animal; D010920:Placenta / Q000378:metabolism* / Q000648:ultrastructure; D011247:Pregnancy
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D004247:DNA