abstract |
An isolated double stranded RNA (double stranded RNA) comprising: i) a first chain, wherein said first chain is 19 to 80 nucleotides in length, and ii) a second chain, wherein said second chain is 19 -35 nucleotides in length, in which with reference to any of Figures 1A, 1B, 5A and 5B, the first and second chains form a duplex in region B of 15-35 base pairs in length; where the first chain comprises an E region at the 3 'end, where the E region comprises a tetrabucle; and the double stranded RNA comprises a discontinuity between the 3 'end of the first chain and the 5' end of the second chain, where the double stranded RNA decreases the target gene expression in a mammalian cell. |