Dosage compensation in Drosophila: the X-chromosomal binding of MSL-1 and MLE is dependent on Sxl activity

EMBO J. 1994 Aug 1;13(15):3542-50.


In Drosophila, dosage compensation, i.e. the equalization of levels of X-linked gene products in the two sexes, is achieved by the hypertranscription of most X-linked genes in males relative to females. The products of at least four genes, collectively termed male-specific lethal (msl) genes, are required for this process and, at least in the case of three of them, mediate this function through an association with the X chromosome in males. We have studied some of the parameters that affect the association of the msl-1 gene product and found that its presence is dependent on the wild-type function of the other three genes, leading to the conclusion that these gene products contribute to the formation of a multi-subunit complex. Furthermore, the X-chromosomal association of the msl-1 and mle gene products is negatively correlated with the level of function of the master regulatory gene Sxl and can assume either a mosaic or a uniform distribution in the tissues of mutant XX individuals. Surprisingly, we also found that the association of these two msl gene products with the two X chromosomes in females of certain mutant genotypes does not result in the hypertranscription of X-linked genes or in any apparent reduction in viability.

Publication types

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

MeSH terms

  • Animals
  • Cell Nucleus / chemistry
  • Chromosomal Proteins, Non-Histone*
  • DNA / metabolism
  • DNA Helicases*
  • DNA-Binding Proteins*
  • Dosage Compensation, Genetic*
  • Drosophila / genetics*
  • Drosophila Proteins*
  • Female
  • Genes, Insect / genetics
  • Genes, Lethal / genetics
  • Histones / analysis
  • Histones / metabolism
  • Insect Hormones / analysis
  • Insect Hormones / metabolism*
  • Male
  • Mutation / physiology
  • Nuclear Proteins / analysis
  • Nuclear Proteins / metabolism*
  • Protein Binding
  • RNA-Binding Proteins*
  • Salivary Glands / chemistry
  • Transcription Factors / analysis
  • Transcription Factors / metabolism*
  • X Chromosome


  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • Drosophila Proteins
  • Histones
  • Insect Hormones
  • Nuclear Proteins
  • RNA-Binding Proteins
  • Sxl protein, Drosophila
  • Transcription Factors
  • mle protein, Drosophila
  • msl-1 protein, Drosophila
  • DNA
  • DNA Helicases