Fig. 4From: Does conservation account for splicing patterns?6-mer count versus conservation enrichment. Total count of each 6-mer versus conservation enrichment in upstream flanking introns (downstream results are similar). The high variation among k-mer counts (σ = 182) indicates substantial selection pressure on flanking introns. More common 6-mers tend to be more conserved (Spearman correlation 0.411, p< 1e-166). The most severely under-conserved k-mers (conservation enrichment less than one-third the background) are also extremely rare, appearing in a tight band along the lower left edge of the plotBack to article page