title: The PIE-1 protein and germline specification in C. elegans embryos.
abstract: Totipotent germline blastomeres in Caenorhabditis elegans contain, but do not respond to, factors that promote somatic differentiation in other embryonic cells. Mutations in the maternal gene pie-1 result in the germline blastomeres adopting somatic cell fates. Here we show that pie-1 encodes a nuclear protein, PIE-1, that is localized to the germline blastomeres throughout early development. During division of each germline blastomere, PIE-1 initially associates with both centrosomes of the mitotic spindle. However, PIE-1 rapidly disappears from the centrosome destined for the somatic daughter, and persists in the centrosome of the daughter that becomes the next germline blastomere. The PIE-1 protein contains potential zinc-finger motifs also found in the mammalian growth-factor response protein TIS-11/NUP475 (refs 4-7). The localization and genetic properties of pie-1 provide an example of a repressor-based mechanism for preserving pluripotency within a stem cell lineage.
authors: Department of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104, USA.
authors: C C
authors: CC
authors: Mello
authors: C
authors: C
authors: Schubert
authors: B
authors: B
authors: Draper
authors: W
authors: W
authors: Zhang
authors: R
authors: R
authors: Lobel
authors: J R
authors: JR
authors: Priess
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001757:Blastomeres / Q000166:cytology; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D019070:Cell Lineage / Q000235:genetics; D018385:Centrosome / Q000502:physiology; D003001:Cloning, Molecular; D017238:Genes, Helminth; D005854:Germ Cells / Q000166:cytology*; D015801:Helminth Proteins / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid; D016335:Zinc Fingers / Q000235:genetics
chemical_list: D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; C100950:pie-1 protein, C elegans