Sex lethal controls dosage compensation in Drosophila by a non-splicing mechanism

Nature. 1997 May 8;387(6629):195-9. doi: 10.1038/387195a0.


Dosage compensation in Drosophila requires the male-specific lethal (msl) proteins (MSL) to make gene expression from the single male X chromosome equivalent to that from both female X chromosomes. Expression of ms12 is repressed post-transcriptionally by Sex lethal (SXL), a female-specific RNA-binding protein that regulates alternative splicing in the sex-determination hierarchy. Although msl2 RNA is alternatively spliced in males and females, this does not alter its coding potential and splicing is not required for male-specific expression of MSL2 protein. Instead, our results suggest that the association of SXL protein with multiple sites in the 5' and 3' untranslated regions of the mx12 transcript represses its translation in females. Thus, this well characterized alternative splicing factor regulates at least one target transcript by a distinct mechanism.

Publication types

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

MeSH terms

  • Alternative Splicing
  • Animals
  • Animals, Genetically Modified
  • Binding Sites
  • DNA-Binding Proteins
  • Dosage Compensation, Genetic*
  • Drosophila / genetics*
  • Drosophila Proteins*
  • Female
  • Genes, Insect*
  • Introns
  • Male
  • Nuclear Proteins / genetics*
  • Poly U
  • Protein Biosynthesis
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA-Binding Proteins / metabolism*
  • Transcription Factors / genetics*


  • DNA-Binding Proteins
  • Drosophila Proteins
  • Nuclear Proteins
  • RNA, Messenger
  • RNA-Binding Proteins
  • Sxl protein, Drosophila
  • Transcription Factors
  • msl-2 protein, Drosophila
  • Poly U