UNC-39, the C. elegans homolog of the human myotonic dystrophy-associated homeodomain protein Six5, regulates cell motility and differentiation

Dev Biol. 2004 Aug 15;272(2):389-402. doi: 10.1016/j.ydbio.2004.05.010.


Mutations in the unc-39 gene of C. elegans lead to migration and differentiation defects in a subset of mesodermal and ectodermal cells, including muscles and neurons. Defects include mesodermal specification and differentiation as well a neuronal migration and axon pathfinding defects. Molecular analysis revealed that unc-39 corresponds to the previously named gene ceh-35 and that the UNC-39 protein belongs to the Six4/5 family of homeodomain transcription factors and is similar to human Six5, a protein implicated in the pathogenesis of type I myotonic dystrophy (DM1). We show that human Six5 and UNC-39 are functional homologs, suggesting that further characterization of the C. elegans unc-39 gene might provide insight into the etiology of DM1.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Caenorhabditis elegans / cytology*
  • Caenorhabditis elegans / embryology
  • Caenorhabditis elegans Proteins / genetics*
  • Caenorhabditis elegans Proteins / metabolism*
  • Cell Differentiation / physiology*
  • Cell Movement / physiology
  • Cheek / growth & development
  • Ectoderm / physiology
  • Embryo, Nonmammalian
  • Embryonic Induction
  • Female
  • Gene Expression Regulation, Developmental
  • Head / embryology
  • Homeodomain Proteins / genetics*
  • Homeodomain Proteins / metabolism*
  • Humans
  • Mesoderm / pathology
  • Molecular Sequence Data
  • Muscles / cytology
  • Muscles / embryology
  • Mutation
  • Neurons / metabolism
  • Neurons / pathology
  • Pharynx / growth & development
  • Sequence Homology, Amino Acid
  • Vulva / cytology
  • Vulva / embryology


  • Caenorhabditis elegans Proteins
  • Homeodomain Proteins
  • SIX5 protein, human
  • Unc-39 protein, C elegans