Dot plots of pre-let-7e (group I) and pre-let-7a-1 (group II). The status of 3′ trimming and 3′ U-tailing for each pre-miRNA read is represented by a circle on a two-dimensional matrix. The
x-axis represents the length of 3′ trimming, and the
y-axis represents the length of U-tail. Area of a circle is proportional to the relative abundance of the pre-miRNA reads. Reference sequence of the hairpin is shown below the dot plot. Position 0 indicates the 3′ end of genomic sequence of most abundant read in control HeLa cells. Pre-let-7e was rarely mono-uridylated in control and was not affected by TUT7/4/2 knockdown. In contrast, about half of pre-let-7a-1 was mono-uridylated in control, and the mono-uridylated reads almost disappeared upon TUT7/4/2 knockdown. The style of the figure was adopted from Zhao
et al (
2012).