Patent ID: 7947823

Claim:
A recombinant vector for the correct, stable and effective expression in mammalian cells of a siRNA or a miRNA, comprising from 5′ to 3′: a) an RNA polymerse II dependent promoter sequence derived from the U1 snRNA gene; b) suitable restriction sites for cloning the sequence that transcribes a presiRNA or a pre-miRNA; c) a sequence transcribing the pre-siRNA or pre-miRNA comprising: in position +1 an A or a G residue; a sequence from 21 to 23 nucleotides corresponding to a sense region of the mRNA transcribed by the gene to be silenced; a sequence selected to form a loop region; a sequence from 21 to 23 nucleotides corresponding to the antisense region of the mRNA transcribed by the gene to be silenced; wherein the residues at the 3′ end protrude in such a way that the following structure is obtained: wherein Y is optionally present, and X and Y if Y is present are independently one or more nucleotides, wherein the nucleotides at the 3′ end are selected to result in asymmetry in siRNA or miRNA strand selection into an interference complex; and d) termination sequences derived from the sequence at 3′ of the gene for U1 snRNA which are necessary and sufficient for the correct formation of the 3′ of the pre-siRNA or of the pre- miRNA, wherein the recombinant vector provides for the correct, stable and effective expression in mammalian cells of a siRNA or a miRNA.