The Drosophila GAGA factor is required for dosage compensation in males and for the formation of the male-specific-lethal complex chromatin entry site at 12DE

Genetics. 2004 Jan;166(1):279-89. doi: 10.1534/genetics.166.1.279.


Drosophila melanogaster males have one X chromosome, while females have two. To compensate for the resulting disparity in X-linked gene expression between the two sexes, most genes from the male X chromosome are hyperactivated by a special dosage compensation system. Dosage compensation is achieved by a complex of at least six proteins and two noncoding RNAs that specifically associate with the male X. A central question is how the X chromosome is recognized. According to a current model, complexes initially assemble at approximately 35 chromatin entry sites on the X and then spread bidirectionally along the chromosome where they occupy hundreds of sites. Here, we report that mutations in Trithorax-like (Trl) lead to the loss of a single chromatin entry site on the X, male lethality, and mislocalization of dosage compensation complexes.

Publication types

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

MeSH terms

  • Animals
  • Chromatin / genetics
  • Crosses, Genetic
  • DNA-Binding Proteins / genetics*
  • Dosage Compensation, Genetic*
  • Drosophila Proteins / genetics*
  • Drosophila melanogaster / genetics*
  • Female
  • Genes, Insect
  • Genes, Lethal
  • Male
  • Models, Genetic
  • Mutation
  • Transcription Factors / genetics*
  • X Chromosome / genetics


  • Chromatin
  • DNA-Binding Proteins
  • Drosophila Proteins
  • Transcription Factors
  • Trl protein, Drosophila