Removal of one dose of Su(var)3-9 leads to subtle change of the HP1 binding pattern on wm4. A) Chromosomal maps of HP1 binding in heterozygous Su(var)3-901and control flies. The Su(var)3-901allele is effectively a null allele . HP1 binding profiles are shown for the same ~400 kb region as in Figure 1, E-G. Black dashed line indicates inversion breakpoint. Inset: eye color in Su(var)3-901/+ and control male flies. B) Close up to ~90 kb region surrounding white; same region is plotted as in Figure 1H. C-D) Chromosomal maps of HP1 binding to parts of chr 2R and chr 4. E) Bar plot showing the average difference in HP1 binding (for each probe on the microarray averaged per chromosome) between control (wm4;+/balancer) and the mutant wm4; Su(var)3-901/+. Xs-c = XSyx4-CG3603 region; chrX = the first 3.2 Mb of the chr X excluding XSyx4-CG3603; chr2R = the parts of chr 2R that are covered on our array. Difference between XS-C and chrX, -0.27 log2; P-value < 2.2*10-16; Wilcoxon rank sum test. F) Chromosomal maps of first 3.4 Mb of X chr, with ΔHP1 (average change in log2 HP1 binding ratio) per gene. ΔHP1 between wm4; Su(var)3-901/+ and control (wm4;+/balancer), Black dots show bottom 5% of genes (n = 16) for which ΔHP1 is largest. Black dotted line indicates inversion breakpoint.