Patent ID: 8137910

Claim:
A method of inhibiting expression of a target gene comprising introducing into an isolated human or non-human animal cell a DNA construct comprising a constitutive or inducible promoter operably linked to a nucleic acid comprising a sequence encoding an artificial micro RNA (miRNA) precursor, wherein said artificial miRNA precursor is a naturally occurring miRNA precursor a portion of the stem of the stem loop structure of said naturally occurring miRNA precursor being substituted by an exogenous sequence complementary to a portion of an RNA transcript of said gene, wherein, following introduction of said construct into said cell: i) said nucleic acid is transcribed so that a transcript comprising said artificial miRNA precursor is produced, ii) said transcript resulting from step (i) is processed so that said artificial miRNA precursor is excised therefrom, iii) said artificial miRNA precursor resulting from step (ii) is processed so that a mature miRNA about 21 or 22 nucleotides in length is excised from said artificial miRNA precursor, and iv) inhibition of expression of said gene is effected.