P element regulation and X-chromosome subtelomeric heterochromatin in Drosophila melanogaster

Genetica. 1997;100(1-3):95-107.


In Drosophila melanogaster, crossing males carrying autonomous P elements with females devoid of P copies results in hybrid dysgenesis in the germline of progeny. The reciprocal cross produces non-dysgenic progeny due to a maternally inherited state non-permissive for P transposition. The capacity of a P copy to repress transposition depends on both its structure and its chromosomal location. Naturally occurring regulatory P elements inserted at the telomere of the X chromosome have been genetically isolated in a genomic context devoid of other P elements. One or two copies of autonomous P elements at this site (1A) are sufficient to elicit a strong P repression in the germline. These elements are flanked by Telomeric Associated Sequences, previously identified and described by Karpen and Spradling (1992) as having heterochromatic properties. The regulatory properties of P elements at 1A are strongly impaired by mutations affecting Su(var)205, which encodes Heterochromatin Protein 1, a non-histone heterochromatin protein. The regulatory properties of classical P strains are not sensitive to Su(var)205. Models based on chromatin structure or on nuclear localisation of the telomeres are discussed in order to explain both the strong regulatory properties of P elements at the X chromosome telomere and their sensitivity to Su(var)205.

Publication types

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

MeSH terms

  • Animals
  • Crosses, Genetic
  • DNA Transposable Elements*
  • Drosophila melanogaster / genetics*
  • Heterochromatin / genetics*
  • Models, Genetic
  • Telomere*
  • X Chromosome*


  • DNA Transposable Elements
  • Heterochromatin