Figure 4
In Drosophila , the identity of the second miRNA nucleotide influences the effect of the first nucleotide. (A) The y-axis shows the significance (Fisher's exact test) of observed covariation between the identity of miRNA nt 1 and nucleotide identity (black) or base-pairing status (gray) along the miRNA and the miRNA* strand. The low values for position 1 in the black curve occur because the identity of miRNA nt 1 correlates strongly with itself. (B and C) Mutating nt 2 in miR-2a (B) or miR-184 (C) changed the order of nt 1 preference for miRNA loading.