AR sequence rate versus GC content. Ancestral repeat (AR) sequence rate is expressed as base pairs (bp) per 100 kilobases (kb). The reduced local GC content observed in AR sequence reflects the process of deamination of methylated CpG to TpG dinucleotides in vertebrate sequence over long evolutionary periods of time . The solid line represents the fit from a cubic smoothing spline, whereas the dashed line is the fit from a robust linear regression.
Clark et al. Genome Biology 2007 8:R180 doi:10.1186/gb-2007-8-9-r180