title: GLP-1 is localized to the mitotic region of the C. elegans germ line.
abstract: In C. elegans, germline mitosis depends on induction by the somatic distal tip cell (DTC) and on activity of the glp-1 gene. Using antibodies to GLP-1 protein, we have examined GLP-1 on western blots and by immunocytochemistry. GLP-1 is tightly associated with membranes of mitotic germline cells, supporting its identification as an integral membrane protein. Furthermore, GLP-1 is localized within the germ line to the mitotic region, consistent with the model that GLP-1 acts as a membrane receptor for the distal tip cell signal. Unexpectedly, GLP-1 and the zone of mitosis extend further than the DTC processes. We present three models by which the DTC may influence GLP-1 activity and thereby determine the zone of mitosis. The spatial restriction of GLP-1 appears to be controlled at the translational level in hermaphrodites. We suggest that down-regulation of GLP-1 may be required to effect the transition from mitosis into meiosis.
authors.affiliation: Laboratory of Molecular Biology, University of Wisconsin 53706, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Crittenden
authors.forename: E R
authors.initials: ER
authors.lastname: Troemel
authors.forename: T C
authors.initials: TC
authors.lastname: Evans
authors.forename: J
authors.initials: J
authors.lastname: Kimble
mesh_terms: D000818:Animals; D015153:Blotting, Western; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins; D002450:Cell Communication / Q000502:physiology; D005455:Fluorescent Antibody Technique; D005854:Germ Cells / Q000737:chemistry / Q000502:physiology*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008562:Membrane Glycoproteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D008938:Mitosis / Q000502:physiology*; D008954:Models, Biological; D051880:Receptors, Notch
chemical_list: D029742:Caenorhabditis elegans Proteins; C060620:Glp-1 protein, C elegans; D008562:Membrane Glycoproteins; D051880:Receptors, Notch