The coordinate regulation of pharyngeal development in C. elegans by lin-35/Rb, pha-1, and ubc-18

Dev Biol. 2004 Jul 1;271(1):11-25. doi: 10.1016/j.ydbio.2004.03.022.


Organ development is a complex process involving the coordination of cell proliferation, differentiation, and morphogenetic events. Using a screen to identify genes that function coordinately with lin-35/Rb during animal development, we have isolated a weak loss-of-function (LOF) mutation in pha-1. lin-35; pha-1 double mutants are defective at an early step in pharyngeal morphogenesis leading to an abnormal pharyngeal architecture. pha-1 is also synthetically lethal with other class B synthetic multivulval (SynMuv) genes including the C. elegans E2F homolog, efl-1. Reporter analyses indicate that pha-1 is broadly expressed during embryonic development and that its functions reside in the cytoplasm. We also provide genetic and phenotypic evidence to support the model that PHA-1, a novel protein, and UBC-18, a ubiquitin-conjugating enzyme that we have previously shown to function with lin-35 during pharyngeal development, act in parallel pathways to regulate the activity of a common cellular target.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Branchial Region / embryology*
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Crosses, Genetic
  • Gene Expression Regulation, Developmental*
  • Genes, Reporter
  • Green Fluorescent Proteins
  • Ligases / genetics
  • Ligases / metabolism
  • Luminescent Proteins
  • Models, Biological*
  • Morphogenesis / genetics
  • Mutation / genetics
  • Phenotype*
  • Polymorphism, Single Nucleotide
  • RNA Interference
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*


  • Caenorhabditis elegans Proteins
  • Luminescent Proteins
  • PHA-1 protein, C elegans
  • Repressor Proteins
  • lin-35 protein, C elegans
  • Green Fluorescent Proteins
  • Ligases
  • Ubc-18 protein, C elegans