Evolutionary and Expression Analysis of miR-#-5p and miR-#-3p at the miRNAs/isomiRs Levels

Figure 1

Primary analysis of human miRNAs according to their locations on pre-miRNAs. (a) Location and length distributions of human miRNAs. There are 849 pairs of miRNAs that are characterized as miR-#-5p and miR-#-3p from the same pre-miRNAs. Despite the fact that 22 nt is predominant length, the length distributions of 5p-miRNA and 3p-miRNA are highly variable (, ). The frequency distribution of -value (difference value) of miR-#-5p and miR-#-3p indicates that the two arms of pre-miRNA are likely to generate different miRNAs with different lengths (, ). (b) Nucleotide compositions between 5p-miRNA and 3p-miRNA, miR-#-5p and miR-#-3p. Guanine (G) is the most predominant nucleotide in 5p-miRNA and miR-#-3p (more than 32%), while moderate distributions of the four nucleotides can be detected in 3p-miRNA and miR-#-3p. The two kinds of miRNAs are likely to have different nucleotide compositions (, ). (c) Difference in nucleotide compositions based on the position along miRNA is detected between 5p-miRNA and 3p-miRNA (, ). The frequency distributions of nucleotides in each position are also presented here. (d) The difference in nucleotide compositions based on position along miRNA is detected between miRNA-#-5p and miRNA-#-3p (, ). The frequency distributions of nucleotides in each position are also presented here.

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