The Broad-Complex directly controls a tissue-specific response to the steroid hormone ecdysone at the onset of Drosophila metamorphosis

EMBO J. 1994 Aug 1;13(15):3505-16.


In Drosophila, all of the major metamorphic transitions are regulated by changes in the titer of the steroid hormone ecdysone. Here we examine how a key regulator of metamorphosis and primary ecdysone response gene, the Broad-Complex, transmits the hormonal signal to one of its targets, the Sgs-4 glue gene. We show that Broad-Complex RNAs accumulate in mid third instar larval salivary glands prior to Sgs-4 induction, as expected for the products of a gene that regulates the timing of Sgs-4 activation. The Broad-Complex codes for a family of zinc finger transcriptional regulators. We have identified a number of binding sites for these proteins in sequences known to regulate the timing of Sgs-4 induction, and have used these sites to derive a binding consensus for each protein. Some of these binding sites are required in vivo for Sgs-4 activity. In addition, rbp+, a genetically defined Broad-Complex function that is required for Sgs-4 induction, acts through these Broad-Complex binding sites. Thus, the Broad-Complex directly mediates a temporal and tissue-specific response to ecdysone as larvae become committed to metamorphosis.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Binding Sites
  • Consensus Sequence
  • DNA / metabolism
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Drosophila / genetics
  • Drosophila / growth & development*
  • Ecdysone / physiology*
  • Female
  • Gene Expression Regulation / genetics*
  • Genes, Insect / genetics*
  • Glue Proteins, Drosophila / genetics
  • Male
  • Metamorphosis, Biological / genetics*
  • Models, Genetic
  • Molecular Sequence Data
  • Regulatory Sequences, Nucleic Acid / genetics
  • Transcription, Genetic / genetics
  • Zinc Fingers / genetics


  • DNA-Binding Proteins
  • Glue Proteins, Drosophila
  • Ecdysone
  • DNA