LARP-1 promotes oogenesis by repressing fem-3 in the C. elegans germline

J Cell Sci. 2010 Aug 15;123(Pt 16):2717-24. doi: 10.1242/jcs.066761. Epub 2010 Jul 27.


LA-related protein 1 (LARP-1) belongs to an RNA-binding protein family containing a LA motif. Here, we identify LARP-1 as a regulator of sex determination. In C. elegans hermaphrodites, a complex regulatory network regulates the switch from sperm to oocyte production. We find that simultaneous depletion of larp-1 and the Nanos homologue nos-3 results in germline masculinization. This phenotype is accompanied by a strong reduction of the levels of TRA-1, a GLI-family transcription factor that promotes oogenesis. TRA-1 levels are regulated by CBC(FEM-1), a ubiquitin ligase consisting of the FEM proteins, FEM-1, FEM-2 and FEM-3 and the cullin CUL-2. We show that both the masculinization phenotype and the reduction of TRA-1 levels observed in nos-3;larp-1 mutants require fem-3 activity, suggesting that nos-3 and larp-1 regulate the sperm-oocyte switch by inhibiting the fem genes. Consistently, fem-3 mRNA levels are increased in larp-1 mutants. By contrast, levels of fem-3 mRNA are not affected in nos-3 mutants. Therefore, our data indicate that LARP-1 and NOS-3 promote oogenesis by regulating fem-3 expression through distinct mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Female
  • MAP Kinase Signaling System
  • Male
  • Mitogen-Activated Protein Kinase 1 / genetics
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mutation
  • Oocytes / physiology
  • Oogenesis / genetics
  • Oogenesis / physiology*
  • Phylogeny
  • RNA-Binding Proteins / metabolism*
  • Sex Determination Processes / physiology*
  • Spermatozoa / physiology


  • Caenorhabditis elegans Proteins
  • LARP-1 protein, C elegans
  • RNA-Binding Proteins
  • fem-3 protein, C elegans
  • Mitogen-Activated Protein Kinase 1
  • mpk-1 protein, C elegans