title: A DTC niche plexus surrounds the germline stem cell pool in Caenorhabditis elegans.
abstract: The mesenchymal distal tip cell (DTC) provides the niche for Caenorhabditis elegans germline stem cells (GSCs). The DTC has a complex cellular architecture: its cell body caps the distal gonadal end and contacts germ cells extensively, but it also includes multiple cellular processes that extend along the germline tube and intercalate between germ cells. Here we use the lag-2 DTC promoter to drive expression of myristoylated GFP, which highlights DTC membranes and permits a more detailed view of DTC architecture. We find that short processes intercalating between germ cells contact more germ cells than seen previously. We define this region of extensive niche contact with germ cells as the DTC plexus. The extent of the DTC plexus corresponds well with the previously determined extent of the GSC pool. Moreover, expression of a differentiation marker increases as germ cells move out of the plexus. Maintenance of this DTC plexus depends on the presence of undifferentiated germ cells, suggesting that germ cell state can influence niche architecture. The roles of this DTC architecture remain an open question. One idea is that the DTC plexus delivers Notch signaling to the cluster of germ cells comprising the GSC pool; another idea is that the plexus anchors GSCs at the distal end.
authors.affiliation: Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States of America ; Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Dana T
authors.initials: DT
authors.lastname: Byrd
authors.affiliation: Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Karla
authors.initials: K
authors.lastname: Knobel
authors.affiliation: Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Katharyn
authors.initials: K
authors.lastname: Affeldt
authors.affiliation: Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Crittenden
authors.affiliation: Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States of America ; Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America ; Laboratory of Molecular Biology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America ; Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Judith
authors.initials: J
authors.lastname: Kimble
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D005786:Gene Expression Regulation; D005854:Germ Cells / Q000166:cytology*; D008164:Luminescent Proteins / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D008938:Mitosis; D055153:Stem Cell Niche
chemical_list: D029742:Caenorhabditis elegans Proteins; C094448:GLD-1 protein, C elegans; D008164:Luminescent Proteins