Caenorhabditis Elegans T-box Genes tbx-9 and tbx-8 Are Required for Formation of Hypodermis and Body-Wall Muscle in Embryogenesis

Genes Cells. 2004 Apr;9(4):331-44. doi: 10.1111/j.1356-9597.2004.00725.x.


Transcription factors containing the DNA binding motif, T-box, play an important role in the embryonic development of metazoans. There are 20 T-box genes in the nematode Caenorhabditis elegans, three of which reportedly have postembryonic functions. We characterized two T-box genes, tbx-9 and tbx-8, that are phylogenetically related to each other. tbx-9 is expressed in a subset of embryonic cells that are precursors of the intestine, body-wall muscle, and hypodermis. The expression pattern of tbx-8 is markedly similar to that of tbx-9. Both tbx-9 mutants and tbx-8 mutants show incomplete penetrant morphogenetic defects in embryogenesis, but the malformations of the tbx-9 and tbx-8 mutants are observed in different parts of their bodies. In embryos with both tbx-9 and tbx-8 inactivated, the body structure is severely disorganized, more so than the sum of the separate mutant phenotypes. Further analysis shows that the hypodermis and body-wall muscle show abnormalities at the site of morphogenetic defects of these mutants. Together, these data indicate that tbx-9 and tbx-8 do not only contribute individually to formation of the hypodermis and body-wall muscle, but also suggests functional redundancy between tbx-9 and tbx-8 in embryonic morphogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Caenorhabditis elegans / embryology
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans Proteins / genetics*
  • Caenorhabditis elegans Proteins / metabolism
  • Immunohistochemistry
  • Molecular Sequence Data
  • Muscles / embryology*
  • Muscles / metabolism
  • Subcutaneous Tissue / embryology*
  • Subcutaneous Tissue / metabolism
  • T-Box Domain Proteins / genetics*
  • T-Box Domain Proteins / metabolism


  • Caenorhabditis elegans Proteins
  • T-Box Domain Proteins
  • Tbx-8 protein, C elegans
  • Tbx-9 protein, C elegans