Figure 3. Substitution rates as a function of nucleosome topology.

Nucleosome footprints in each genome (human, Hfx. volcanii) were lined up according to the inferred dyad and base-specific substitution rates along the focal (red) and sister (blue) lineages calculated at given distances (in nucleotides) from the dyad. Lines indicate LOWESS fits (smoother span f = 0.6), grey dots represent by-nucleotide-distance estimates for the focal lineages (omitted for clarity for the sister lineages). The number of substitutions (N) is given for each base change category along with P values for linear regression models, weighted by the number of eligible sites at each distance from the dyad. The maximum plotted distance from the dyad is chosen species-specifically to cover the typical nucleosome footprint plus neighbouring linker sequence in the different taxa.