title: The establishment of Caenorhabditis elegans germline pattern is controlled by overlapping proximal and distal somatic gonad signals.
abstract: We investigated the control of proliferation and differentiation in the larval Caenorhabditis elegans hermaphrodite germ line through analysis of glp-1 and lag-2 mutants, cell ablations, and ultrastructural data. After the first several rounds of germ cell division, GLP-1, a receptor of the LIN-12/Notch family, governs germline proliferation. We analyzed the proximal proliferation (Pro) phenotype in glp-1(ar202) and found that initial meiosis was delayed and spatially mispositioned. This is due, at least in part, to a heightened response of the mutant GLP-1 receptor to multiple sources of the somatic ligand LAG-2, including the proximal somatic gonad. We investigated whether proximal LAG-2 affects germline proliferation in the wild type. Our results indicate that (1) LAG-2 is necessary for GLP-1-mediated germline proliferation and prevention of early meiosis, and (2) several distinct anatomical sources of LAG-2 in the larval somatic gonad functionally overlap to promote proliferation and prevent early meiosis. Ultrastructural studies suggest that mitosis is not restricted to areas of direct DTC-germ line contact and that the germ line shares a common cytoplasm in larval stages. We propose that downregulation of the GLP-1 signaling pathway in the proximal germ line at the time of meiotic onset is under tight temporal and spatial control.
authors.affiliation: Department of Biology, New York University, New York, NY 10003, USA.
authors.forename: Anita S-R
authors.initials: AS
authors.lastname: Pepper
authors.forename: Te Wen
authors.initials: TW
authors.lastname: Lo
authors.forename: Darrell J
authors.initials: DJ
authors.lastname: Killian
authors.forename: David H
authors.initials: DH
authors.lastname: Hall
authors.forename: E Jane Albert
authors.initials: EJ
authors.lastname: Hubbard
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics / Q000502:physiology; D002454:Cell Differentiation; D002455:Cell Division; D019070:Cell Lineage; D012734:Disorders of Sex Development; D005260:Female; D005854:Germ Cells / Q000502:physiology* / Q000648:ultrastructure; D006066:Gonads / Q000378:metabolism* / Q000648:ultrastructure; D015801:Helminth Proteins / Q000235:genetics; D007814:Larva; D008297:Male; D008954:Models, Biological; D009154:Mutation; D010641:Phenotype; D015398:Signal Transduction; D013696:Temperature
chemical_list: D015801:Helminth Proteins