Drosophila ribosomal RNA genes function as an X-Y pairing site during male meiosis

Cell. 1990 Apr 6;61(1):61-72. doi: 10.1016/0092-8674(90)90215-z.


In Drosophila melanogaster males, the sex chromosomes pair during meiosis in the centric X heterochromatin and at the base of the short arm of the Y (YS), in the vicinity of the nucleolus organizers. X chromosomes deficient for the pairing region segregate randomly from the Y. In this report we show that a single ribosomal RNA (rRNA) gene stimulates X-Y pairing and disjunction when inserted onto a heterochromatically deficient X chromosome by P element-mediated transformation. We also show that insert-containing X chromosomes pair at the site of insertion, that autosomal rDNA inserts do not affect X-Y pairing or disjunction, and that the strength of an X pairing site is proportional to the dose of ectopic rRNA genes. These results demonstrate that rRNA genes can promote X-Y pairing and disjunction and imply that the nucleolus organizers function as X-Y pairing sites in wild-type Drosophila males.

Publication types

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

MeSH terms

  • Animals
  • Blotting, Southern
  • Crosses, Genetic
  • DNA Transposable Elements
  • DNA, Ribosomal / genetics*
  • Drosophila melanogaster / genetics*
  • Drosophila melanogaster / physiology
  • Female
  • Genes*
  • Male
  • Meiosis*
  • Mutation
  • Nucleic Acid Hybridization
  • Plasmids
  • RNA, Ribosomal / genetics*
  • Transcription, Genetic
  • X Chromosome*
  • Y Chromosome*


  • DNA Transposable Elements
  • DNA, Ribosomal
  • RNA, Ribosomal