aubergine mutations in Drosophila melanogaster impair P cytotype determination by telomeric P elements inserted in heterochromatin.
Transposable P elements inserted in the heterochromatic Telomeric Associated Sequences on the X chromosome (1A site) of Drosophila melanogaster have a very strong capacity to elicit the P cytotype, a maternally transmitted condition which represses P element transposition and P-induced hybrid dysgenesis. This repressive capacity has previously been shown to be sensitive to mutant alleles of the gene Su(var)205, which encodes HP1 (Heterochromatin Protein 1), thus suggesting a role for chromatin structure in repression. Since an interaction between heterochromatin formation and RNA interference has been reported in various organisms, we tested the effect of mutant alleles of aubergine, a gene that has been shown to play a role in RNA interference in Drosophila, on the repressive properties of telomeric P elements. Seven out of the eight mutant alleles tested clearly impaired the repressive capacities of the two independent telomeric P insertions at 1A analyzed. P repression by P strains whose repressive capacities are not linked to the presence of P copies at 1A were previously found to be insensitive to Su(var)205; here, we show that they are also insensitive to aubergine mutations. These results strongly suggest that both RNA interference and heterochromatin structure are involved in the establishment of the P cytotype elicited by telomeric P elements, and reinforce the hypothesis that different mechanisms for repression of P elements exist which depend on the chromosomal location of the regulatory copies of P.
Reiss
D
D
Laboratoire Dynamique du Génome et Evolution, Institut Jacques Monod, UMR7592, CNRS-Universités Paris 6 et 7, 2 Place Jussieu, 75251, Paris 05, France.
Josse
T
T
Anxolabéhère
D
D
Ronsseray
S
S
D000483:Alleles; D000818:Animals; D000090266:Chromobox Protein Homolog 5; D029721:Drosophila Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D006059:Gonadal Dysgenesis; D006570:Heterochromatin / Q000235:genetics*; D008297:Male; D009154:Mutation; D010448:Peptide Initiation Factors / Q000235:genetics*; D034622:RNA Interference; D016615:Telomere
D029721:Drosophila Proteins; D006570:Heterochromatin; D010448:Peptide Initiation Factors; C000716867:Su(var)205 protein, Drosophila; C436124:aub protein, Drosophila; D000090266:Chromobox Protein Homolog 5