An antagonistic role for the C. elegans Schnurri homolog SMA-9 in modulating TGFbeta signaling during mesodermal patterning

Development. 2006 Aug;133(15):2887-96. doi: 10.1242/dev.02476. Epub 2006 Jun 21.


In C. elegans, the Sma/Mab TGFbeta signaling pathway regulates body size and male tail patterning. SMA-9, the C. elegans homolog of Schnurri, has been shown to function as a downstream component to mediate the Sma/Mab TGFbeta signaling pathway in these processes. We have discovered a new role for SMA-9 in dorsoventral patterning of the C. elegans post-embryonic mesoderm, the M lineage. In addition to a small body size, sma-9 mutant animals exhibit a dorsal-to-ventral fate transformation within the M lineage. This M lineage defect of sma-9 mutants is unique in that animals carrying mutations in all other known components of the TGFbeta pathway exhibit no M lineage defects. Surprisingly, mutations in the core components of the Sma/Mab TGFbeta signaling pathway suppressed the M lineage defects of sma-9 mutants without suppressing their body size defects. We show that this suppression specifically happens within the M lineage. Our studies have uncovered an unexpected role of SMA-9 in antagonizing the TGFbeta signaling pathway during mesodermal patterning, suggesting a novel mode of function for the SMA-9/Schnurri family of proteins.

Publication types

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

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Body Patterning
  • Body Size
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / physiology*
  • Embryo, Nonmammalian / physiology*
  • Gene Deletion
  • Mesoderm / physiology*
  • Signal Transduction
  • Transcription Factors / deficiency
  • Transcription Factors / genetics
  • Transcription Factors / physiology*
  • Transforming Growth Factor beta / antagonists & inhibitors*
  • Zinc Fingers


  • Caenorhabditis elegans Proteins
  • Sma-9 protein, C elegans
  • Transcription Factors
  • Transforming Growth Factor beta