Figure 1. Rolling Circle Transcription (RCT) approach to expressing miRNA, siRNA and other small RNA.

A. Circular oligodeoxynucleotides (COLIGOs) are made to encode minimal pri-miRNAs. RCT would produce tandemly arrayed primary miRNA stem-loops resembling naturally occurring miRNA clusters to promote entry into the endogenous miRNA maturation pathway, and Argonaute effector complexes (RISC) programming. B. RNA transcript sequences and the predicted secondary structures of the four COLIGOs used in this study. Mature miRNA are shaded, number in parentheses refers to number of nucleotides in COLIGO and its monomeric transcript, which is shown arbitrarily beginning outside of the stem-loop.