The generation of small RNAs; who needs Dicer?
نویسنده
چکیده
Up until 2006 it was believed that most, if not all, small RNAs in RNA silencing were synthesized via members of the Dicer-like RNase III endonuclease family. In animals, small interfering RNAs (siRNAs) are cleaved from long double-stranded RNA by Dicer enzymes, and microRNAs (miRNAs) are released from genome-encoded stem-loop precursors through the sequential action of Droshas and Dicers. In plants, members of the Dicer-like (DCL) family function together in the biosynthesis of siRNAs, miRNAs and trans-acting siRNAs (tasiRNAs). Now, large-scale small RNA sequencing projects and improved methods for the characterisation of small RNAs have revealed two, perhaps three, new and distinct Dicer-independent mechanisms for the generation of small RNAs.
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