title: Reprogrammed transcriptome in rhesus-bovine interspecies somatic cell nuclear transfer embryos.
abstract: BACKGROUND
  Global activation of the embryonic genome (EGA), one of the most critical steps in early mammalian embryo development, is recognized as the time when interspecies somatic cell nuclear transfer (iSCNT) embryos fail to thrive.
  
  
  RESULTS
  In this study, we analyzed the EGA-related transcriptome of rhesus-bovine iSCNT 8- to 16-cell embryos and dissected the reprogramming process in terms of embryonic gene activation, somatic gene silencing, and maternal RNA degradation. Compared with fibroblast donor cells, two thousand and seven genes were activated in iSCNT embryos, one quarter of them reaching expression levels comparable to those found in in vitro fertilized (IVF) rhesus embryos. This suggested that EGA in iSCNT embryos had partially recapitulated rhesus embryonic development. Eight hundred and sixty somatic genes were not silenced properly and continued to be expressed in iSCNT embryos, which indicated incomplete nuclear reprogramming. We compared maternal RNA degradation in bovine oocytes between bovine-bovine SCNT and iSCNT embryos. While maternal RNA degradation occurred in both SCNT and iSCNT embryos, we saw more limited overall degradation of maternal RNA in iSCNT embryos than in SCNT embryos. Several important maternal RNAs, like GPF9, were not properly processed in SCNT embryos.
  
  
  CONCLUSIONS
  Our data suggested that iSCNT embryos are capable of triggering EGA, while a portion of somatic cell-associated genes maintain their expression. Maternal RNA degradation seems to be impaired in iSCNT embryos. Further understanding of the biological roles of these genes, networks, and pathways revealed by iSCNT may expand our knowledge about cell reprogramming, pluripotency, and differentiation.
authors.affiliation: Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Hasan H
authors.initials: HH
authors.lastname: Otu
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Young
authors.initials: Y
authors.lastname: Lee
authors.forename: Keith
authors.initials: K
authors.lastname: Latham
authors.forename: Jose B
authors.initials: JB
authors.lastname: Cibelli
mesh_terms: D000818:Animals; D002417:Cattle; D065150:Cellular Reprogramming / Q000235:genetics*; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism*; D005260:Female; D005307:Fertilization in Vitro; D023281:Genomics; D008253:Macaca mulatta; D053652:Nuclear Transfer Techniques; D020411:Oligonucleotide Array Sequence Analysis; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism; D015203:Reproducibility of Results; D059467:Transcriptome