Heat-shock increases nucleosome fragility at the promoter and gene body of up-regulated genes. (A) Experimental overview. Mixed-stage embryos were either incubated at room temperature (RT) or heat-shocked at 34°C (HS) for 20 min. Subsequently, embryos were fixed and used for an MNase-seq time-course or stored in TRIzol and used for RNA-seq. (B) mRNA-seq identifies differentially expressed genes after HS at 34°C. Significantly differentially expressed genes (padj < 0.1) shown in red. (C) RNA, fragility, resistance, and nucleosome occupancy scores with and without HS are plotted in the region surrounding F33E5.4 and F33E5.5, two divergently transcribed hsp-70 orthologs. Region plotted is Chr II position 11,749,925–11,770,394. (D) Nucleosome fragility and nucleosome occupancy at 14 significantly differentially expressed genes with and without HS. (E) Nucleosome fragility, resistance, and occupancy scores at all 20,785 coding genes with and without HS.
