title: Ultrastructural and molecular distinctions between the porcine inner cell mass and epiblast reveal unique pluripotent cell states.
abstract: Characterization of the pluripotent cell populations within the porcine embryo is essential for understanding pluripotency and self-renewal regulation in the inner cell mass (ICM) and epiblast. In this study, we perform detailed ultrastructural and molecular characterization of the developing pluripotent cell population as it develops from the ICM to the late epiblast. The ultrastructural observations revealed that the outer cells of the ICM have a high nuclear:cytoplasmic ratio but are transcriptionally inactive and contain mitochondria with few cristae. In contrast, the epiblast cells have a reduced nuclear:cytoplasmic ratio, are more transcriptionally active, and contain abundant cellular organelles. This study also revealed cavitation and potential unfolding of the epiblast. As the ICM forms the epiblast, SSEA1 is lost and VIMENTIN is lost and re-expressed. The D6 blastocyst expressed high levels of STELLA, TERF1, and GDF3, and the epiblast expressed epithelial markers, MUC1 and E-CADHERIN, and the pluripotency markers, DNMT3B and CRIPTO.
authors.affiliation: Department of Basic Animal and Veterinary Sciences, Faculty of LIFE Sciences, University of Copenhagen, Copenhagen, Denmark. vha@life.ku.dk
authors.forename: Vanessa J
authors.initials: VJ
authors.lastname: Hall
authors.forename: Janus V
authors.initials: JV
authors.lastname: Jacobsen
authors.forename: Mikkel A
authors.initials: MA
authors.lastname: Rasmussen
authors.forename: Poul
authors.initials: P
authors.lastname: Hyttel
mesh_terms: D000818:Animals; D053624:Blastocyst Inner Cell Mass / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure*; D015820:Cadherins / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism*; D005855:Germ Layers / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure*; D055451:Growth Differentiation Factor 3 / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D016256:Lewis X Antigen / Q000378:metabolism; D051379:Mice; D046529:Microscopy, Electron, Transmission; D018396:Mucin-1 / Q000378:metabolism; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure*; D016133:Polymerase Chain Reaction; D013552:Swine; D035321:Telomeric Repeat Binding Protein 1 / Q000378:metabolism; D019108:Tight Junctions / Q000378:metabolism; D014746:Vimentin / Q000378:metabolism
chemical_list: D015820:Cadherins; D055451:Growth Differentiation Factor 3; D016256:Lewis X Antigen; D018396:Mucin-1; D035321:Telomeric Repeat Binding Protein 1; D014746:Vimentin; D004248:DNA (Cytosine-5-)-Methyltransferases