Notch signaling and morphogenesis of single-cell tubes in the C. elegans digestive tract

Dev Cell. 2008 Apr;14(4):559-69. doi: 10.1016/j.devcel.2008.01.019.


During organogenesis of the C. elegans digestive system, epithelial cells within a cyst-like primordium develop diverse shapes through largely unknown mechanisms. We here analyze two adjacent, dorsal epithelial cells, called pm8 and vpi1, that remodel their shapes and apical junctions to become donut-shaped, or toroidal, single-cell tubes. pm8 and vpi1 delaminate from the dorsal cyst epithelium and migrate ventrally, across the midline of the cyst, on a transient tract of laminin. pm8 appears to encircle the midline by wrapping around finger-like projections from neighboring cells. Finally, pm8 and vpi1 self-fuse to become toroids by expressing AFF-1 and EFF-1, two fusogens that are each sufficient to promote crossfusion between other cell types. Notch signaling in pm8 induces AFF-1 expression, while simultaneously repressing EFF-1 expression; vpi1 expresses EFF-1 independent of Notch. Thus, the adjacent pm8 and vpi1 cells express different fusogens, allowing them to self-fuse into separate, single-cell tubes while avoiding crossfusion.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Patterning*
  • Caenorhabditis elegans* / anatomy & histology
  • Caenorhabditis elegans* / embryology
  • Caenorhabditis elegans* / metabolism
  • Cell Fusion
  • Cell Movement
  • Cell Polarity
  • Cell Shape
  • Epithelial Cells / cytology
  • Epithelial Cells / metabolism
  • Gastrointestinal Tract* / cytology
  • Gastrointestinal Tract* / embryology
  • Gastrointestinal Tract* / metabolism
  • Humans
  • Laminin / metabolism
  • Morphogenesis / physiology*
  • Receptors, Notch / genetics
  • Receptors, Notch / metabolism*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction / physiology
  • Transgenes


  • Laminin
  • Receptors, Notch
  • Recombinant Fusion Proteins