title: Requirement of Oct3/4 function for germ cell specification.
abstract: In mammalian embryos, PGCs (primordial germ cells) are specified from a pluripotent epiblast cell population after implantation. In this study, we demonstrated an essential role for the germline-specific transcription factor Oct3/4 in PGC specification. We generated chimeric embryos with ZHBTc4 ES cells lacking both alleles of the Oct3/4 gene (pou5f1). Pluripotency was maintained by an Oct3/4 transgene, and its expression was suppressed by doxycycline (Dox). Transcription of the Oct3/4 transgene in the ES-derived cells unexpectedly suffered constitutive suppression in chimeric embryos without Dox, and the ES-derived cells contributed to PGC precursor-like cells, but failed to form PGCs. We then attempted to rescue Oct3/4 expression in the ES-derived cells in the chimeric embryos by introducing an additional Oct3/4 transgene. The ES cell-derived cells indeed recovered Oct3/4 transcription in these chimeric embryos, and were successfully specified to PGCs. We further confirmed the requirement of Oct3/4 by using another derivative of ZHBTc4 ES cells in which a Dex (dexamethasone)-dependent Oct3/4 transgene was introduced. In the presence of Dox, Oct3/4 protein was absent in the nuclei of the ES-derived cells, which failed to form PGCs. In contrast, the ES-derived cells could be specified to PGCs after activation of Oct3/4 function in the presence of Dex.
authors.affiliation: Cell Resource Center for Biomedical Research, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-machi, Sendai 980-8575, Japan.
authors.forename: Daiji
authors.initials: D
authors.lastname: Okamura
authors.forename: Yuko
authors.initials: Y
authors.lastname: Tokitake
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Niwa
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Matsui
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D045744:Cell Line, Tumor; D002678:Chimera / Q000196:embryology; D017931:DNA Primers / Q000235:genetics; D004318:Doxycycline / Q000494:pharmacology; D053595:Embryonic Stem Cells / Q000166:cytology*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology*; D005854:Germ Cells / Q000166:cytology*; D049452:Green Fluorescent Proteins; D006801:Humans; D051379:Mice; D050814:Octamer Transcription Factor-3 / Q000378:metabolism / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019076:Transgenes / Q000235:genetics
chemical_list: D017931:DNA Primers; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D049452:Green Fluorescent Proteins; D004318:Doxycycline