Characterization of sequences associated with position-effect variegation at pericentric sites in Drosophila heterochromatin

Chromosoma. 1998 Nov;107(5):277-85. doi: 10.1007/s004120050309.


In a variety of organisms, euchromatic genes brought into juxtaposition with pericentric heterochromatin show position-effect variegation (PEV), a silencing of gene expression in a subset of the cells in which the gene is normally expressed. Previously, a P-element mobilization screen identified transgenic Drosophila stocks showing PEV of an hsp70-white+ reporter gene; transgenes in many of these stocks map to the chromocenter of polytene chromosome. A screen at an elevated temperature identified two stocks that under standard culture temperatures show complete repression of the hsp70-white+ transgene. The transgenes in both cases map to the chromocenter of polytene chromosomes. Different types of middle repetitive elements are adjacent to seven pericentric transgenes; unique sequences are adjacent to two of the perimetric transgenes. All of the transgenes show suppression of PEV in response to a mutation in the gene encoding heterochromatin protein 1 (HP1). This suppression correlates with a more accessible chromatin structure. The results indicate that a pericentric transgene showing PEV can be associated with different types of DNA sequences, while maintaining a common association with the chromosomal protein HP1.

Publication types

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

MeSH terms

  • ATP-Binding Cassette Transporters*
  • Animals
  • Animals, Genetically Modified
  • Chromosomal Proteins, Non-Histone / genetics
  • DNA Transposable Elements
  • Drosophila Proteins*
  • Drosophila melanogaster / genetics*
  • Eye Color / genetics
  • Eye Proteins*
  • Female
  • HSP70 Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / genetics
  • Heterochromatin / genetics*
  • Insect Proteins / genetics
  • Male
  • Mutation
  • Repetitive Sequences, Nucleic Acid*
  • Transgenes


  • ATP-Binding Cassette Transporters
  • Chromosomal Proteins, Non-Histone
  • DNA Transposable Elements
  • Drosophila Proteins
  • Eye Proteins
  • HSP70 Heat-Shock Proteins
  • Heat-Shock Proteins
  • Heterochromatin
  • Hsp26 protein, Drosophila
  • Insect Proteins
  • w protein, Drosophila
  • heterochromatin-specific nonhistone chromosomal protein HP-1