A dicentric chromosome of Drosophila melanogaster showing alternate centromere inactivation

Chromosoma. 2000 Jun;109(3):190-6. doi: 10.1007/s004120050427.


Dicentric chromosomes are rarely found, because they interfere with normal cell division causing chromosome instability. By in situ hybridization of region-specific heterochromatic yeast artificial chromosomes we have found that the artificially generated C(1)A chromosome of Drosophila melanogaster has two potential centromeres: one carries all the sequences of the centromere of the Y chromosome and the other carries only a part of the Y centromeric region that is rich in telomere-related sequences. Immunostaining with anti-Bub1 (a kinetochore-specific marker) shows that, in spite of the differences in sequence, both centromeres can be active although as a rule only one at a time. In a small fraction of the chromosomes centromere inactivation is incomplete, giving rise to true dicentric chromosomes. The centromere inactivation is clonally inherited, providing a new example of epigenetic chromosome imprinting and the possibility of genetically dissecting this process. The involvement of telomere-related sequences in centromere function is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Centromere / genetics*
  • Chromosomes, Artificial, Yeast / genetics
  • Cytogenetic Analysis
  • Drosophila melanogaster / genetics*
  • Fluorescent Antibody Technique
  • Genomic Imprinting
  • Heterochromatin / genetics
  • In Situ Hybridization, Fluorescence
  • Protein Kinases / metabolism
  • Protein-Serine-Threonine Kinases
  • Telomere / genetics
  • Y Chromosome / genetics*


  • Heterochromatin
  • Protein Kinases
  • Bub1 spindle checkpoint protein
  • Protein-Serine-Threonine Kinases