The bluetail transposon: evidence for independent cis-regulatory domains and domain boundaries in the bithorax complex

EMBO J. 1993 Mar;12(3):1087-97.


An extremely large cis-regulatory region generates the parasegment-specific expression patterns of the homeotic genes in the bithorax complex. We present evidence supporting the idea that this cis-regulatory region is subdivided into independent cis-regulatory domains. We describe a Ubx-lacZ transposon which is inserted into one of these domains, iab-7. The PS12-specific pattern of LacZ expression from this reporter indicates that it is subject to the control of the iab-7 cis-regulatory domain, but is protected from the effects of adjacent regulatory domains. Protection on the proximal side appears to be provided by the Fab-7 boundary element. Deletion of this boundary results in the ectopic activation of iab-7 in PS11 (where the iab-6 cis-regulatory domain normally functions). We show that the Fab-7 boundary, like other boundaries, has an unusual chromatin structure.

Publication types

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

MeSH terms

  • Animals
  • Chromatin / chemistry
  • DNA Transposable Elements*
  • Drosophila melanogaster
  • Larva
  • Mutation
  • RNA, Messenger / genetics
  • Regulatory Sequences, Nucleic Acid*
  • Thorax / embryology
  • beta-Galactosidase / genetics


  • Chromatin
  • DNA Transposable Elements
  • RNA, Messenger
  • beta-Galactosidase