Résumé
Scaffold‐associated regions (SARs) were studied in Drosophila melanogaster by expressing a synthetic, high‐affinity SAR‐binding protein called MATH (multi‐AT‐hook), which consists of reiterated AT‐hook peptide motifs; each motif is known to recognize a wide variety of short AT‐rich sequences. MATH proteins were expressed specifically in the larval eye imaginal discs by means of the tetracycline‐regulated transactivation system and tested for their effect on position effect variegation (PEV). MATH20, a highly potent SAR ligand consisting of 20 AT‐hooks, was found to suppress whitemottled 4 variegation. This suppression required MATH20 expression at an early larval developmental stage. Our data suggest an involvement of the high AT‐rich SARs in higher order chromatin structure and gene expression.