title: microRNA expression during trophectoderm specification.
abstract: BACKGROUND
  Segregation of the trophectoderm from the inner cell mass of the embryo represents the first cell-fate decision of mammalian development. Transcription factors essential for specifying trophectoderm have been identified, but the role of microRNAs (miRNAs) in modulating this fate-choice has been largely unexplored. We have compared miRNA expression in embryonic stem cell (ESC)-derived trophectoderm and in staged murine embryos to identify a set of candidate miRNAs likely to be involved in trophectoderm specification.
  
  
  RESULTS
  We profiled embryonic stem cells (ESCs) as they were induced to differentiate into trophectodermal cells by ectopic expression of HRas/Q61L. We also profiled murine embryos at progressive stages of preimplantation development (zygote, 2-cell, 4-cell, 8-cell, morula, and blastocyst), which includes the time window in which the trophectoderm is specified in vivo Q61L/H.
  
  
  CONCLUSIONS
  We describe miRNA expression changes that occur during trophectoderm specification and validate that our in vitro system faithfully recapitulates trophectoderm specification in vivo. By comparing our in vitro and in vivo datasets, we have identified a minimal set of candidate miRNAs likely to play a role in trophectoderm specification. These miRNAs are predicted to regulate a host of development-associated target genes, and many of these miRNAs have previously reported roles in development and differentiation. Additionally, we highlight a number of miRNAs whose tight developmental regulation may reflect a functional role in other stages of embryogenesis. Our embryo profiling data may be useful to investigators studying trophectoderm specification and other stages of preimplantation development.
authors: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA, USA.
authors: Srinivas R
authors: SR
authors: Viswanathan
authors: Craig H
authors: CH
authors: Mermel
authors: Jun
authors: J
authors: Lu
authors: Chi-Wei
authors: CW
authors: Lu
authors: Todd R
authors: TR
authors: Golub
authors: George Q
authors: GQ
authors: Daley
mesh_terms: D000818:Animals; D001755:Blastocyst; D002454:Cell Differentiation / Q000235:genetics; D019070:Cell Lineage; D004475:Ectoderm / Q000166:cytology*; D051379:Mice; D035683:MicroRNAs / Q000235:genetics*; D039904:Pluripotent Stem Cells / Q000166:cytology
chemical_list: D035683:MicroRNAs