Figure 4.

Nucleosome positioning by H3 ChIP analysis. (a,b)ChIP of cross-linked H3 at the promoter sites of HSF23 (a) and HSP70 (b) reveal well-positioned -1 and +1 nucleosomes. The x-axis indicates the central position of each amplicon relative to the TSS. In each schematic, the promoter (solid line), 5'UTR (white box), exons (black box) and TSS (arrow) are shown. (c-e)ChIP of cross-linked H3 for genes that were detected to be up-regulated (c), constant (d) or down-regulated (e) in response to temperature reveal sites that show strong enrichment of H3 at probable +1 nucleosome sites according to in silicosequence analysis (see Materials and methods). The x-axis indicates the central position of each amplicon relative to the TSS. Values from H3 and mock reactions are shown in black and grey, respectively. Values are the mean ± standard error of three biological replicates.