RNA interference mediating small RNA molecules

摘要

Double-stranded RNA (dsRNA) induces sequence-specific post-transcriptional gene silencing in many organisms by a process known as RNA interference (RNAi). Using a Drosophila in vitro system, we demonstrate that 19-23 nt short RNA fragments are the sequence-specific mediators of RNAi. The short interfering RNAs (siRNAs) are generated by an RNase III-like processing reaction from long dsRNA. Chemically synthesized siRNA duplexes with overhanging 3′ ends mediate efficient target RNA cleavage in the lysate, and the cleavage site is located near the center of the region spanned by the guiding siRNA. Furthermore, we provide evidence that the direction of dsRNA processing determines whether sense or antisense target RNA can be cleaved by the produced siRNP complex.

主权项

1. A eukaryotic cell or a eukaryotic non-human organism comprising at least one double-stranded RNA molecule capable of mediating RNA interference, wherein:
(i) each RNA strand of the RNA molecule independently consists of 19 to 25 nucleotides in length; (ii) at least one RNA strand of the RNA molecule forms a single-stranded 3′-overhang from 1 to 5 nucleotides; (iii) a strand of the RNA molecule is at least 85% identical to a target mRNA molecule in the double-stranded portion of the RNA molecule; and (iv) the RNA molecule comprises at least one nucleotide analogue.