title: Wnt signaling controls the stem cell-like asymmetric division of the epithelial seam cells during C. elegans larval development.
abstract: Metazoan stem cells repopulate tissues during adult life by dividing asymmetrically to generate another stem cell and a cell that terminally differentiates. Wnt signaling regulates the division pattern of stem cells in flies and vertebrates. While the short-lived nematode C. elegans has no adult somatic stem cells, the lateral epithelial seam cells divide in a stem cell-like manner in each larval stage, usually generating a posterior daughter that retains the seam cell fate and an anterior daughter that terminally differentiates. We show that while wild-type adult animals have 16 seam cells per side, animals with reduced function of the TCF homolog POP-1 have as many as 67 seam cells, and animals with reduced function of the β-catenins SYS-1 and WRM-1 have as few as three. Analysis of seam cell division patterns showed alterations in their stem cell-like divisions in the L2-L4 stages: reduced Wnt signaling caused both daughters to adopt non-seam fates, while activated Wnt signaling caused both daughters to adopt the seam fate. Therefore, our results indicate that Wnt signaling globally regulates the asymmetric, stem cell-like division of most or all somatic seam cells during C. elegans larval development, and that Wnt pathway regulation of stem cell-like behavior is conserved in nematodes.
authors.forename: Julie E
authors.initials: JE
authors.lastname: Gleason
authors.forename: David M
authors.initials: DM
authors.lastname: Eisenmann
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D029742:Caenorhabditis elegans Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D002452:Cell Count; D002454:Cell Differentiation; D002455:Cell Division; D003598:Cytoskeletal Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism; D017930:Genes, Reporter; D006609:High Mobility Group Proteins / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D007814:Larva; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000502:physiology; D012097:Repressor Proteins / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D051153:Wnt Proteins / Q000502:physiology*
chemical_list: C525389:BRO-1 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; C493287:RNT-1 protein, C elegans; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C502083:Sys-1 protein, C elegans; D014157:Transcription Factors; C120104:WRM-1 protein, C elegans; D051153:Wnt Proteins; C115014:bar-1 protein, C elegans; C096787:pop-1 protein, C elegans