Pattern formation in the limbs of Drosophila: bric à brac is expressed in both a gradient and a wave-like pattern and is required for specification and proper segmentation of the tarsus

Development. 1993 Nov;119(3):799-812. doi: 10.1242/dev.119.3.799.


We have identified the gene bric à brac and show that it is required for pattern formation along the proximal-distal axis of the leg and antenna of Drosophila. In bric à brac mutant legs, the bristle pattern of the three central tarsal segments is transformed towards the pattern of the most proximal tarsal segment. In addition, bric à brac mutant legs and antennae have segmentation defects. bric à brac encodes a nuclear protein that shares a highly conserved domain with two transcription factors from Drosophila. bric à brac function is dosage dependent and is required in a graded manner for the specification of tarsal segments. The graded requirement for bric à brac correlates with its graded expression pattern, suggesting that the concentration of BRIC A BRAC protein specifies segment identity in the tarsus.

Publication types

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

MeSH terms

  • Animals
  • Drosophila melanogaster / embryology*
  • Drosophila melanogaster / genetics
  • Extremities / embryology*
  • Gene Expression / physiology
  • Genes, Homeobox / physiology*
  • In Situ Hybridization
  • Morphogenesis / genetics
  • Mutation / genetics
  • Phenotype