Figure 6. H4K20me3 is enriched in late-replicating null RFD regions (NRR).

(a) 3 × 5 panel of 2D histograms of H4K20me3 chromatin immunoprecipitation relative read frequencies versus replication timing (RT) (average log₂(Early/Late) over 100 kb binned according to the decile of RT distribution). The analysis was performed in 10 kb bins. Histograms are normalized by column and displayed for different bin categories (columns: intergenic regions, silent genes, expressed genes; rows: all bins, ascending segment [AS], descending segment [DS], unidirectionally replicating region [URR], null replication fork directionality region [NRR] bins) as for origin recognition complex/minichromosome maintenance complex (ORC/MCM) in Figure 4. The number of bins per histogram is indicated in each panel. Superimposed boxplots represent the mean (circle), median (thick line), first and third quartile (box), and first and ninth decile (whiskers) of the relative read frequencies in each timing bins. Refer to Figure 5—figure supplement 1g for statistical comparisons. (b) Histogram representation of mean ±2 × SEM of ORC/MCM relative read frequencies at 3986 H4K20me3-low NRR 10 kb bins and 504 H4K20me3-high NRR 10 kb bins. Statistics were performed using one-sided t-test. ***p<0.001.