TRA-1 ChIP-seq reveals regulators of sexual differentiation and multilevel feedback in nematode sex determination

Proc Natl Acad Sci U S A. 2013 Oct 1;110(40):16033-8. doi: 10.1073/pnas.1312087110. Epub 2013 Sep 17.


How sexual regulators translate global sexual fate into appropriate local sexual differentiation events is perhaps the least understood aspect of sexual development. Here we have used ChIP followed by deep sequencing (ChIP-seq) to identify direct targets of the nematode global sexual regulator Transformer 1 (TRA-1), a transcription factor acting at the interface between organism-wide and cell-specific sexual regulation to control all sex-specific somatic differentiation events. We identified 184 TRA-1-binding sites in Caenorhabditis elegans, many with temporal- and/or tissue-specific TRA-1 association. We also identified 78 TRA-1-binding sites in the related nematode Caenorhabditis briggsae, 19 of which are conserved between the two species. Some DNA segments containing TRA-1-binding sites drive male-specific expression patterns, and RNAi depletion of some genes adjacent to TRA-1-binding sites results in defects in male sexual development. TRA-1 binds to sites adjacent to a number of heterochronic regulatory genes, some of which drive male-specific expression, suggesting that TRA-1 imposes sex specificity on developmental timing. We also found evidence for TRA-1 feedback regulation of the global sex-determination pathway: TRA-1 binds its own locus and those of multiple upstream masculinizing genes, and most of these associations are conserved in C. briggsae. Thus, TRA-1 coordinates sexual development by reinforcing the sex-determination decision and directing downstream sexual differentiation events.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / physiology*
  • Chromatin Immunoprecipitation
  • Computational Biology
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Feedback, Physiological / physiology*
  • Female
  • Gene Expression Regulation, Developmental / genetics
  • Gene Expression Regulation, Developmental / physiology*
  • Male
  • RNA Interference
  • Sequence Analysis, DNA
  • Sex Determination Processes / genetics
  • Sex Determination Processes / physiology*
  • Sex Differentiation / genetics
  • Sex Differentiation / physiology*
  • Transcription Factors / genetics
  • Transcription Factors / physiology*


  • Caenorhabditis elegans Proteins
  • DNA-Binding Proteins
  • Transcription Factors
  • tra-1 protein, C elegans

Associated data

  • GEO/GSE48917