Dun1 modulates telomeric silencing strength in an Asf1- and Hir1-dependent manner. (A) dun1Δ suppresses the cac1Δ telomeric silencing defect, but only when ASF1 and HIR1 genes are intact. Strains were (top to bottom): PKY090, PKY638, PKY3583, PKY3584, PKY3586, PKY3591, PKY3588, and PKY3592. (B) Overexpression of the CRT1 transcriptional repressor has no effect on telomeric silencing. Wild-type (PKY090) and cac1Δ strains (PKY638) were transformed with pRS423 (2μ-HIS3 vector) or pMH151-7 (2μ-HIS3-CRT1). Transformants were plated onto histidine-deficient synthetic media with and without 5′-FOA. (C) Overexpression of RNR genes has no effect on telomeric silencing. Wild-type and cac1Δ strains containing pBAD54 (2μ-TRP1 plasmid + galactose-inducible GAP promoter), pBAD70 (2μ-TRP1 + GAP-RNR1), or pBAD79 (2μ-TRP1 + GAP-RNR3) were plated on tryptophan-deficient synthetic media (with and without 5′-FOA) containing galactose to induce overexpression. Strains were PKY2256, PKY2259, PKY2262, PKY2258, PKY2261, and PKY2264.