Fig. 5
From: Patterns of microsatellite distribution across eukaryotic genomes
Motif size dependent distribution of SSRs among various genomic features. a Boxplots representing the proportion of SSRs in intergenic regions, introns, and exons across subgroups. The distribution of SSRs in intergenic and intronic regions (shaded boxes) mostly mirror their genomic distributions (non-shaded boxes). However, we see a small but significant underrepresentation of SSRs in exons (right panel, p < 10e-40, paired-sample t-test). b Average distribution of SSRs in coding and non-coding regions in all species studied, colored by the size of repeat motif. The percentage of trimer and hexamer repeats is higher in exonic SSRs at the expense of tetramers and dimers. The fraction of each motif size is calculated as the total bases covered by SSRs of a given motif size divided by the total bases covered by all SSRs. This value is multiplied by 100 to derive percentages (the total for all motif sizes add up to 100), represented on the Y-axis