Repression by the 3' UTR of fem-3, a sex-determining gene, relies on a ubiquitous mog-dependent control in Caenorhabditis elegans

EMBO J. 1998 Nov 2;17(21):6337-47. doi: 10.1093/emboj/17.21.6337.


The fem-3 sex-determining gene is repressed post-transcriptionally via a regulatory element in its 3' untranslated region (UTR) to achieve the switch from spermatogenesis to oogenesis in the Caenorhabditis elegans hermaphrodite germ line. In this paper, we investigate the fem-3 3' UTR control in somatic tissues using transgenic reporter assays, and we also identify six genes essential for this control. First, we find that a reporter transgene bearing a wild-type fem-3 3' UTR is repressed in somatic tissues, whereas one bearing a mutant fem-3 3' UTR is derepressed. Moreover, control by mutant 3' UTRs is temperature sensitive as predicted from the temperature sensitivity of the fem-3 gain-of-function (gf) mutations. Secondly, we find a fem-3 3' UTR RNA-binding activity in somatic tissues, in addition to the previously reported germ-line-specific binding by FBF. Thirdly, we find that each of six genes, mog-1-mog-6, is required for repression by the fem-3 3' UTR. Therefore, the mog genes not only affect the sperm/oocyte switch in the germ line, but also function in somatic tissues. We suggest that the mog genes may encode components of a ubiquitous machinery that is used for fem-3 3' UTR-mediated repression and the sperm/oocyte switch.

Publication types

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

MeSH terms

  • 3' Untranslated Regions / genetics*
  • Animals
  • Animals, Genetically Modified
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans Proteins*
  • Gene Expression Regulation, Developmental / genetics*
  • Genes, Helminth / genetics
  • Genes, Reporter / genetics
  • Helminth Proteins / genetics*
  • Histocytochemistry
  • Mutation / genetics
  • Phenotype
  • RNA, Messenger / genetics
  • RNA-Binding Proteins / genetics
  • Regulatory Sequences, Nucleic Acid / genetics
  • Sex Determination Processes*
  • Temperature


  • 3' Untranslated Regions
  • Caenorhabditis elegans Proteins
  • Helminth Proteins
  • RNA, Messenger
  • RNA-Binding Proteins
  • fem-3 protein, C elegans