B1-mediated silencing effects in ARS1 and core X. ARS1-URA-tel, URA-ARS1-tel, GF6, GF44, ARS1(B1−)-URA-tel, URA-ARS1(B1−)-tel, GF6(B1−), and GF44(B1−) were inserted in the VII-L telomere of wild type (MCM5, W303) and mutant (mcm5-461, orc2-1, orc5-1, and cdc45-1) strains and %FOAR was determined for each construct/strain combination. Raw data are shown in Supplemental Table 3. (A) The ratio %FOAR(B1−)/%FOARB1 for ARS1-URA-tel and URA-ARS1-tel is plotted to show the effect of destruction of B1 in the strains shown on the left. (B) The ratio %FOAR(B1−)/%FOARB1 for GF44 and GF6 is plotted to show the effect of destruction of B1 in the strains shown on the left. (C) The ratio %FOARGF6(B1−ΔSTAR)/%FOARGF6 shows the effect of destruction of B1 in the absence of STAR element.