Figure 6.

U and A are the preferential non-templated nucleotides added to mature miRNAs. (A) Both D. melanogaster and C. elegans miR-1 miRNAs contain non-templated nucleotide (marked in blue) extension at 3′ end. The frequency of the four types of 5′ and 3′ nucleotides based on corrected authentic miRNA sequences in D. melanogaster (B) and C. elegans (C). Frequency of the extended non-templated nucleotide based on the type of the last nucleotide (denoted by a red rectangle in miR-1 example) and the following nucleotide (denoted by a blue rectangle in miR-1 example) in D. melanogaster (D) and in C. elegans (E).