The fog-3 gene and regulation of cell fate in the germ line of Caenorhabditis elegans

Genetics. 1995 Feb;139(2):561-77.


In the nematode Caenorhabditis elegans, germ cells normally adopt one of three fates: mitosis, spermatogenesis or oogenesis. We have identified and characterized the gene fog-3, which is required for germ cells to differentiate as sperm rather than as oocytes. Analysis of double mutants suggests that fog-3 is absolutely required for spermatogenesis and acts at the end of the regulatory hierarchy controlling sex determination for the germ line. By contrast, mutations in fog-3 do not alter the sexual identity of other tissues. We also have characterized the null phenotype of fog-1, another gene required for spermatogenesis; we demonstrate that it too controls the sexual identity of germ cells but not of other tissues. Finally, we have studied the interaction of these two fog genes with gld-1, a gene required for germ cells to undergo oogenesis rather than mitosis. On the basis of these results, we propose that germ-cell fate might be controlled by a set of inhibitory interactions among genes that specify one of three fates: mitosis, spermatogenesis or oogenesis. Such a regulatory network would link the adoption of one germ-cell fate to the suppression of the other two.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Caenorhabditis elegans
  • Chromosome Mapping
  • Female
  • Genes, Helminth / physiology*
  • Genes, Regulator / physiology*
  • Genetic Complementation Test
  • Germ Cells / physiology*
  • Male
  • Models, Genetic
  • Molecular Sequence Data
  • Mutation / physiology
  • Oogenesis / genetics
  • Phenotype
  • Sex Differentiation / genetics*
  • Spermatogenesis / genetics*