FIG. 6.

Spreading of Sir3 in yaf9Δ strains. (A) Sir3-Myc levels are identical in WT and yaf9Δ strains, as shown by immunoblot analysis of whole-cell extracts derived from WT and yaf9Δ strains. (B) Sir3-Myc occupancy at telomere 14R in WT and yaf9Δ strains, as revealed by G-ChIP analysis. Input DNA was labeled with Cy3 (green) and DNA enriched by ChIP was labeled with Cy5 (red) and hybridized competitively to the genomic microarray. Cy5/Cy3 ratios were normalized as described in the supplemental data. Spots corresponding to loci at telomere 14R were culled from the array (from one experiment) and arranged according to the physical map. Similar enrichments were observed in three separate experiments. (C) As in panel B, but for telomere 3R. (D) Sir3 occupancy and spreading in the yaf9Δ strain at telomeres 3R and 14R, as revealed by qPCR. Figure 5A shows the physical locations of primer set amplicons. Values represent the enrichment of Sir3 in yaf9Δ cells divided by that in WT cells (see Materials and Methods). Values shown represent the median of three independent ChIP experiments with qPCR determinations performed twice (see the supplemental data). Chr, chromosome.