title: Global gene expression of the inner cell mass and trophectoderm of the bovine blastocyst.
abstract: BACKGROUND
  The first distinct differentiation event in mammals occurs at the blastocyst stage when totipotent blastomeres differentiate into either pluripotent inner cell mass (ICM) or multipotent trophectoderm (TE). Here we determined, for the first time, global gene expression patterns in the ICM and TE isolated from bovine blastocysts. The ICM and TE were isolated from blastocysts harvested at day 8 after insemination by magnetic activated cell sorting, and cDNA sequenced using the SOLiD 4.0 system.
  
  
  RESULTS
  A total of 870 genes were differentially expressed between ICM and TE. Several genes characteristic of ICM (for example, NANOG, SOX2, and STAT3) and TE (ELF5, GATA3, and KRT18) in mouse and human showed similar patterns in bovine. Other genes, however, showed differences in expression between ICM and TE that deviates from the expected based on mouse and human.
  
  
  CONCLUSIONS
  Analysis of gene expression indicated that differentiation of blastomeres of the morula-stage embryo into the ICM and TE of the blastocyst is accompanied by differences between the two cell lineages in expression of genes controlling metabolic processes, endocytosis, hatching from the zona pellucida, paracrine and endocrine signaling with the mother, and genes supporting the changes in cellular architecture, stemness, and hematopoiesis necessary for development of the trophoblast.
authors.affiliation: Department of Animal Sciences and D,H, Barron Reproductive and Perinatal Biology Research Program, PO Box 110910, Gainesville, FL 32611-0910, USA.
authors.forename: Manabu
authors.initials: M
authors.lastname: Ozawa
authors.forename: Miki
authors.initials: M
authors.lastname: Sakatani
authors.forename: JiQiang
authors.initials: J
authors.lastname: Yao
authors.forename: Savita
authors.initials: S
authors.lastname: Shanker
authors.forename: Fahong
authors.initials: F
authors.lastname: Yu
authors.forename: Rui
authors.initials: R
authors.lastname: Yamashita
authors.forename: Shunichi
authors.initials: S
authors.lastname: Wakabayashi
authors.forename: Kenta
authors.initials: K
authors.lastname: Nakai
authors.forename: Kyle B
authors.initials: KB
authors.lastname: Dobbs
authors.forename: Mateus José
authors.initials: MJ
authors.lastname: Sudano
authors.forename: William G
authors.initials: WG
authors.lastname: Farmerie
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hansen
mesh_terms: D000818:Animals; D053624:Blastocyst Inner Cell Mass / Q000378:metabolism*; D002417:Cattle; D016000:Cluster Analysis; D018899:CpG Islands; D004475:Ectoderm / Q000166:cytology / Q000378:metabolism*; D046149:Embryo Culture Techniques; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D053858:Metabolic Networks and Pathways; D051379:Mice; D058977:Molecular Sequence Annotation; D011401:Promoter Regions, Genetic; D059467:Transcriptome; D014327:Trophoblasts / Q000378:metabolism*; D015854:Up-Regulation