Figure 1. Sequence of rat insulin I mRNA. (A) The complete sequence of rat insulin I mRNA (463 nucleotides long) was obtained from NCBI (NM_019129.3). The 3′UTR region is located between 391–463 nucleotides (underlined). The seed region of the miR-25/32/363/92a/92b family is highlighted in gray. Sequence of specific primers used to amplify the 3′UTR region is shown in bold italics. Core binding region of PTBP1 is shown in a box. (B) miR-25 and miR-92a consensus binding sequence in rat and mouse. Binding of miR-25 and miR-92a at the 3′UTR of rat and mouse insulin are predicted by either miRWalk or miRanda or both. Although the programs did not include prediction for rat insulin II, the seed region of miR-25 and miR-92a is conserved in rat and mouse for both insulin I and II. The PTBP1 binding site is underlined. The sequences corresponding to human insulin and the partially overlapping seed region and PTBP1 binding site are also shown.