title: EGO-1, a putative RNA-directed RNA polymerase, promotes germline proliferation in parallel with GLP-1/notch signaling and regulates the spatial organization of nuclear pore complexes and germline P granules in Caenorhabditis elegans.
abstract: Caenorhabditis elegans EGO-1, a putative cellular RNA-directed RNA polymerase, promotes several aspects of germline development, including proliferation, meiosis, and gametogenesis, and ensures a robust response to RNA interference. In C. elegans, GLP-1/Notch signaling from the somatic gonad maintains a population of proliferating germ cells, while entry of germ cells into meiosis is triggered by the GLD-1 and GLD-2 pathways. GLP-1 signaling prevents germ cells from entering meiosis by inhibiting GLD-1 and GLD-2 activity. We originally identified the ego-1 gene on the basis of a genetic interaction with glp-1. Here, we investigate the role of ego-1 in germline proliferation. Our data indicate that EGO-1 does not positively regulate GLP-1 protein levels or GLP-1 signaling activity. Moreover, GLP-1 signaling does not positively regulate EGO-1 activity. EGO-1 does not inhibit expression of GLD-1 protein in the distal germline. Instead, EGO-1 acts in parallel with GLP-1 signaling to influence the proliferation vs. meiosis fate choice. Moreover, EGO-1 and GLD-1 act in parallel to ensure germline health. Finally, the size and distribution of nuclear pore complexes and perinuclear P granules are altered in the absence of EGO-1, effects that disrupt germ cell biology per se and probably limit germline growth.
authors.affiliation: Department of Biology, Syracuse University, Syracuse, New York 13244, USA.
authors.forename: Valarie E
authors.initials: VE
authors.lastname: Vought
authors.forename: Mitsue
authors.initials: M
authors.lastname: Ohmachi
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Lee
authors.forename: Eleanor M
authors.initials: EM
authors.lastname: Maine
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000201:enzymology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation; D003594:Cytoplasmic Granules / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D019084:Fluorescent Antibody Technique, Indirect; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D008562:Membrane Glycoproteins / Q000378:metabolism; D022022:Nuclear Pore / Q000378:metabolism*; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000378:metabolism*; D051880:Receptors, Notch / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*
chemical_list: D029742:Caenorhabditis elegans Proteins; C060620:Glp-1 protein, C elegans; D008562:Membrane Glycoproteins; D051880:Receptors, Notch; C406772:EGO-1 protein, C elegans; D012324:RNA-Dependent RNA Polymerase