Genetic inhibition by double-stranded RNA
A process is provided of introducing an RNA into a living cell to inhibit gene expression of a target gene in that cell. The process may be practiced ex vivo or in vivo. The RNA has a region with double-stranded structure. Inhibition is sequence-specific in that the nucleotide sequences of the duplex region of the RNA and of a portion of the target gene are identical. The present invention is distinguished from prior art interference in gene expression by antisense or triple-strand methods.
1 - 21 . (canceled)
22 . A method to inhibit expression of a target gene comprising:
(a) providing an organism containing a target cell, wherein the target cell contains the target gene and the target gene is expressed in the target cell;
(b) contacting a ribonucleic acid (RNA) with the organism, wherein the RNA is comprised of a double-stranded structure with duplexed ribonucleic acid strands and one of the strands is able to duplex with a portion of the target gene; and
(c) introducing the RNA into the target cell, thereby inhibiting expression of the target gene.
23 . The method of claim 22 in which the organism is an animal.
24 . The method of claim 22 in which the organism is a plant.
25 . The method of claim 22 in which the organism is an invertebrate animal.
26 . The method of claim 22 in which the organism is a nematode.
27 . The method of claim 26 in which a formulation comprised of the RNA is applied on or adjacent to a plant, and disease associated with nematode infection of the plant is thereby reduced.
28 . The method of claim 22 in which the identical nucleotide sequence is at least 50 nucleotides in length.
29 . The method of claim 22 in which the expression of the target gene is inhibited by at least 10%.
30 . The method of claim 22 in which the RNA is introduced within a body cavity of the organism and outside the target cell.
31 . The method of claim 22 in which the RNA is introduced by extracellular injection into the organism.
32 . The method of claim 22 in which the organism is contacted with the RNA by feeding the organism food containing the RNA.
33 . The method of claim 32 in which a genetically-engineered host transcribing the RNA comprises the food.
34 . The method of claim 22 in which at least one strand of the RNA is produced by transcription of an expression construct.
35 . The method of claim 35 in which the organism is a nematode and the expression construct is contained in a plant, and disease associated with nematode infection of the plant is thereby reduced.
36 . A cell containing an expression construct,
wherein the expression construct transcribes at least one ribonucleic acid (RNA) and the RNA forms a double-stranded structure with duplexed strands of ribonucleic acid,
whereby said cell contains the double-stranded RNA structure and is able to inhibit expression of a target gene when the RNA is contacted with an organism containing the target gene.
37 . A transgenic animal containing said cell of claim 36 .
38 . A transgenic plant containing said cell of claim 36 .
39 . A kit comprising reagents for inhibiting expression of a target gene in a cell,
wherein said kit comprises a means for introduction of a ribonucleic acid (RNA) into the cell in an amount sufficient to inhibit expression of the target gene, and
wherein the RNA has a double-stranded structure with an identical nucleotide sequence as compared to a portion of the target gene.