Fig. 4: Heat weakens chromatin compartmentation.
a Pie chart showing the percentages of chromatin compartment switching induced by heat. A compartment: active compartment; B compartment: repressive compartment. b Saddle plots of chromatin compartmentalization: mean cis observed interaction frequencies divided by expected interaction frequency between 20 kb bins. The plots are ordered by PC1 values from Control. Interactions between A compartments are in the top right, and interactions between B compartments are in the bottom left. c Compartment strengths in Control and Heat for each chromosome arm split by centromere. Compartment strength is defined as natural logarithm of interactions of AA + BB normalized by interactions of AB. For the box plot, center lines indicate the medians; boxes show the 25th and 75th percentiles; whiskers extend to the minimum and maximum. d Heatmap showing contact frequencies between and within chromosomes 3 and 4 in Control and Heat. The upper- and lower-triangular matrices correspond to Control and Heat, respectively. The values on the diagonal line (interactions between nearby bins) are assigned to zero. The KEEs are highlighted by dashed, red circles and interconnected by dashed lines to indicate the relationships with each other and the positions of KEEs in the linear genome. The track below shows the positions of centromeres (black), pericentromeres (gray), the knob hk4s (blue), and KEEs (red). The lower panel shows the positions and differential expression of heat-activated TEs within chromosomes 3 and 4, PC1 values in Control condition, PC1 values in Heat condition, and ∆PC1 values (PC1Heat − PC1Control) horizontally. The positive PC1 values indicate A compartments. The negative PC1 values indicate B compartments. The positions of pericentromeres and the knob hk4s with increased PC1 values are indicated. Source data underlying a and d are provided as a Source Data file.
