Identification of microRNAs in ecological model plant Mimulus

MicroRNAs (miRNAs) are small, non-coding and regulatory RNAs about 20 to 24 nucleotides long. Their conserved nature among the various organisms makes them a good source of new miRNAs discovery by comparative genomics approach. This study resulted in 34 miRNAs belonging to 21 families in ecological model plant Mimulus. All the miRNA families (mir 156, 157, 159, 160, 164, 172, 319, 393, 395, 397, 399, 400, 403, 417, 419, 472, 782, 854, 858, 867 and 2112) are found for the first time in Mimulus. The MIR-399 is found as precursor miRNA cluster with 4 mature sequences. All 34 miRNA precursors form stable minimum free energy stem loop structure as their orthologues form and the mature miRNAs reside in the stem portion of the stem loop structure. Twenty eight are from Mimulus guttatus and six miRNAs belong to Mimulus lewisii. Their targets consist of dihy-droflavonol-4-reductase, cycloidea-like protein, DNA-directed RNA polymerase II, maturase (matR) and transcription factors like; squamosa-promoter binding, MYB, palmate-like pentafoliata 1.