cis-regulatory requirements for tissue-specific programs of the circadian clock

Curr Biol. 2014 Jan 6;24(1):1-10. doi: 10.1016/j.cub.2013.11.017. Epub 2013 Dec 12.


Background: Broadly expressed transcriptions factors (TFs) control tissue-specific programs of gene expression through interactions with local TF networks. A prime example is the circadian clock: although the conserved TFs CLOCK (CLK) and CYCLE (CYC) control a transcriptional circuit throughout animal bodies, rhythms in behavior and physiology are generated tissue specifically. Yet, how CLK and CYC determine tissue-specific clock programs has remained unclear.

Results: Here, we use a functional genomics approach to determine the cis-regulatory requirements for clock specificity. We first determine CLK and CYC genome-wide binding targets in heads and bodies by ChIP-seq and show that they have distinct DNA targets in the two tissue contexts. Computational dissection of CLK/CYC context-specific binding sites reveals sequence motifs for putative partner factors, which are predictive for individual binding sites. Among them, we show that the opa and GATA motifs, differentially enriched in head and body binding sites respectively, can be bound by OPA and SERPENT (SRP). They act synergistically with CLK/CYC in the Drosophila feedback loop, suggesting that they help to determine their direct targets and therefore orchestrate tissue-specific clock outputs. In addition, using in vivo transgenic assays, we validate that GATA motifs are required for proper tissue-specific gene expression in the adult fat body, midgut, and Malpighian tubules, revealing a cis-regulatory signature for enhancers of the peripheral circadian clock.

Conclusions: Our results reveal how universal clock circuits can regulate tissue-specific rhythms and, more generally, provide insights into the mechanism by which universal TFs can be modulated to drive tissue-specific programs of gene expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ARNTL Transcription Factors / genetics
  • ARNTL Transcription Factors / metabolism*
  • Animals
  • Binding Sites
  • CLOCK Proteins / genetics
  • CLOCK Proteins / metabolism*
  • Circadian Clocks*
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / metabolism*
  • Genome, Insect
  • Genome-Wide Association Study
  • Organ Specificity
  • Regulatory Sequences, Nucleic Acid
  • Transcription, Genetic


  • ARNTL Transcription Factors
  • Drosophila Proteins
  • cyc protein, Drosophila
  • CLOCK Proteins

Associated data

  • GEO/GSE40467