P element regulation and X-chromosome subtelomeric heterochromatin in Drosophila melanogaster.
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.
Ronsseray
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S
Département Dynamique du Génome et Evolution, Institut Jacques Monod, UMR9922 CNRS-Université Denis Diderot, Paris, France.
Lehmann
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M
Nouaud
D
D
Anxolabéhère
D
D
D000818:Animals; D000090266:Chromobox Protein Homolog 5; D003433:Crosses, Genetic; D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D006570:Heterochromatin / Q000235:genetics*; D008957:Models, Genetic; D016615:Telomere; D014960:X Chromosome
D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D006570:Heterochromatin; C000716867:Su(var)205 protein, Drosophila; D000090266:Chromobox Protein Homolog 5