FIGURE 1. RNA silencing pathways in different organisms.
From the following article:
Unlocking the potential of the human genome with RNA interference
Gregory J. Hannon and John J. Rossi
Nature 431, 371-378(16 September 2004)
doi:10.1038/nature02870
Long dsRNA and miRNA precursors are processed to siRNA/miRNA duplexes by the RNase-III-like enzyme Dicer. These short dsRNAs are subsequently unwound and assembled into effector complexes, RISCs, which can direct RNA cleavage, mediate translational repression or induce chromatin modification. S. pombe, C. elegans and mammals carry only one Dicer gene. In D. melanogaster and A. thaliana, specialized Dicer or DLC proteins preferentially process long dsRNA or miRNA precursors. 7mG, 7-methyl guanine; AAAA, poly-adenosine tail; Me, methyl group; P, 5' phosphate.