title: C. elegansGLP-1/Notch activates transcription in a probability gradient across the germline stem cell pool.
abstract: C. elegansNotch signaling maintains a pool of germline stem cells within their single-celled mesenchymal niche. Here we investigate the Notch transcriptional response in germline stem cells using single-molecule fluorescencein situhybridization coupled with automated, high-throughput quantitation. This approach allows us to distinguish Notch-dependent nascent transcripts in the nucleus from mature mRNAs in the cytoplasm. We find that Notch-dependent active transcription sites occur in a probabilistic fashion and, unexpectedly, do so in a steep gradient across the stem cell pool. Yet these graded nuclear sites create a nearly uniform field of mRNAs that extends beyond the region of transcriptional activation. Therefore, active transcription sites provide a precise view of where the Notch-dependent transcriptional complex is productively engaged. Our findings offer a new window into the Notch transcriptional response and demonstrate the importance of assaying nascent transcripts at active transcription sites as a readout for canonical signaling.
authors.affiliation: Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, United States.|Department of Biochemistry, University of Wisconsin-Madison, Madison, United States.
authors.forename: ChangHwan
authors.initials: C
authors.lastname: Lee
authors.affiliation: Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, United States.|Department of Biochemistry, University of Wisconsin-Madison, Madison, United States.
authors.forename: Erika B
authors.initials: EB
authors.lastname: Sorensen
authors.affiliation: Department of Biochemistry, University of Wisconsin-Madison, Madison, United States.
authors.forename: Tina R
authors.initials: TR
authors.lastname: Lynch
authors.affiliation: Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, United States.|Department of Biochemistry, University of Wisconsin-Madison, Madison, United States.
authors.forename: Judith
authors.identifier: 0000-0001-5622-2073
authors.initials: J
authors.lastname: Kimble
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D000066473:Embryonic Germ Cells / Q000502:physiology*; D017404:In Situ Hybridization, Fluorescence; D051880:Receptors, Notch / Q000378:metabolism*; D000072760:Single Molecule Imaging; D013234:Stem Cells / Q000502:physiology*; D014158:Transcription, Genetic
chemical_list: D029742:Caenorhabditis elegans Proteins; C060620:Glp-1 protein, C elegans; D051880:Receptors, Notch
keywords: C. elegans; active transcription site; cell biology; developmental biology; lst-1; single-molecule FISH; stem cells; sygl-1