easternblot (November 30, 1999 at 12:00 am)

Yes, it's the same. The difference is earlier: miRNAs are first processed in the nucleus by Drosha - siRNA and shRNA (usually) are not. shRNA are ceaved by Dicer in the cytoplasm. siRNA resembles the product of Dicer. All three (miRNA processed by Drosha/Dicer, shRNA cleaved by Dicer, and siRNA) are about the same shape and size at this point and are all recognized by the RISC complex.

QuantumKitten2 (November 30, 1999 at 12:00 am)

Hmm... is the RISC holoenzyme the same for endogenous miRNAs and transfected siRNAs/shRNAs?