Trans-silencing by P elements inserted in subtelomeric heterochromatin involves the Drosophila Polycomb group gene, Enhancer of zeste.
Drosophila P-element transposition is regulated by a maternally inherited state known as P cytotype. An important aspect of P cytotype is transcriptional repression of the P-element promoter. P cytotype can also repress non-P-element promoters within P-element ends, suggesting that P cytotype repression might involve chromatin-based transcriptional silencing. To learn more about the role of chromatin in P cytotype repression, we have been studying the P strain Lk-P(1A). This strain contains two full-length P elements inserted in the heterochromatic telomere-associated sequences (TAS elements) at cytological location 1A. Mutations in the Polycomb group gene (Pc-G gene), Enhancer of zeste (E(z)), whose protein product binds at 1A, resulted in a loss of Lk-P(1A) cytotype control. E(z) mutations also affected the trans-silencing of heterologous promoters between P-element termini by P-element transgenes inserted in the TAS repeats. These data suggest that pairing interactions between P elements, resulting in exchange of chromatin structures, may be a mechanism for controlling the expression and activity of P elements.
Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3204, USA.
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D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D017344:Genes, Insect; D006570:Heterochromatin / Q000235:genetics; D019476:Insect Proteins / Q000235:genetics; D008297:Male; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D010641:Phenotype; D063150:Polycomb Repressive Complex 1; D063151:Polycomb Repressive Complex 2; D012097:Repressor Proteins / Q000235:genetics; D016615:Telomere / Q000235:genetics
D017931:DNA Primers; D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D006570:Heterochromatin; D019476:Insect Proteins; D009687:Nuclear Proteins; C066770:Pc protein, Drosophila; D012097:Repressor Proteins; C083329:E(z) protein, Drosophila; D063151:Polycomb Repressive Complex 2; D063150:Polycomb Repressive Complex 1