MicroRNAs are 19-22 nt-long RNAs that regulate eukaryotic gene expression. They are processed from stem-loop containing precursor transcripts by RNAse III enzymes of the Dicer family. In this issue of the EMBO Journal, a study by Bologna and colleagues investigates the processing of two plant MIRNA families with unusually long precursors. Their findings suggest a non-canonical mode of biogenesi...
