IN-VIVO ANALYSIS OF SCAFFOLD-ASSOCIATED REGIONS IN DROSOPHILA - A SYNTHETIC HIGH-AFFINITY SAR BINDING-PROTEIN SUPPRESSES POSITION EFFECT VARIEGATION

Scaffold-associated regions (SARs) were studied in Drosophila melanoga ster by expressing a synthetic, high-affinity SAR-binding protein call ed MATH (multi-AT-hook), which consists of reiterated AT-hook peptide motifs; each motif is known to recognize a wide variety of short AT-ri ch sequences. MATH proteins mere expressed specifically in the larval eye imaginal discs by means of the tetracycline-regulated transactivat ion system and tested for their effect on position effect variegation (PEV). MATH20, a highly potent SAR ligand consisting of 20 AT-hooks, w as found to suppress white(mottled4) variegation. This suppression req uired MATH20 expression at an early larval developmental stage. Our da ta suggest an involvement of the high AT-rich SARs in higher order chr omatin structure and gene expression.