Gene silencing

Abstract

Compositions and methods are disclosed for effecting gene silencing (e.g., post transcriptional gene silencing) in an organism by targeting 15-20 nucleotides of mRNA.

1 . A composition for introduction into a cell to effect gene silencing, consisting essentially of isolated short antisense RNA molecules (SARMs) and isolated short sense RNA molecules (SSRMs), collectively short RNA molecules (SRMs),
 wherein said SARMS are complementary to, and can base pair with, 15-20 consecutive nucleotides of a target RNA, which target RNA is transcribed from a gene that is silenced when said SRMs are present in a cell containing said gene, and said SSRMs correspond to the target RNA; and   wherein said gene is endogenous to an organism selected from the group consisting of a plant, a mammal, an avian organism, a reptile, an insect, and a protozoan, or   said target RNA is generated by a pathogen.   
     
     
         2 . The composition of  claim 1  wherein said SRMs are unmodified or synthetic. 
     
     
         3 . A method of silencing a gene in cells which method comprises introducing into said cells an effective amount of the composition of  claim 1 ,
 whereby said gene is silenced.   
     
     
         4 . The method of  claim 3 , wherein the cells are contained in an organism and said introducing comprises administering said SRMs to the organism. 
     
     
         5 . Cells prepared by the method of  claim 3 . 
     
     
         6 . A non-human organism prepared by the method of  claim 4 . 
     
     
         7 . An improved composition for introduction into a cell to effect gene silencing, which improved composition comprises isolated short antisense RNA molecules (SARMs);
 wherein said SARMs are complementary to, and can base pair with, 15-20 consecutive nucleotides of a target RNA, and;   the improvement comprising including in said composition isolated short sense RNA molecules (SSRMs) wherein said SSRMs are complementary to said SARMs; and   wherein said target RNA is transcribed from a gene that is silenced when said SSRMs and SARMs are present in a cell containing said gene,   wherein said gene is endogenous to an organism selected from the group consisting of a plant, a mammal, an avian organism, a reptile, an insect, and a protozoan; or said target RNA is generated by a pathogen.   
     
     
         8 . The composition of  claim 7  wherein said SRMs are unmodified or synthetic. 
     
     
         9 . A method of silencing a gene in cells which method comprises introducing into said cells an effective amount of the composition of  claim 7 ,
 whereby said gene is silenced.   
     
     
         10 . The method of  claim 9 , wherein the cells are contained in an organism and said introducing comprises administering said SRMs to the organism. 
     
     
         11 . Cells prepared by the method of  claim 9 . 
     
     
         12 . A non-human organism prepared by the method of  claim 10 . 
     
     
         13 . A composition for introduction into a cell to effect gene silencing, which composition comprises at least one vector which, when introduced into a cell, produces short antisense RNA molecules (SARMs) and short sense RNA molecules (SSRMs), said SARMs and SSRMs designated, collectively, short RNA molecules (SRMs),
 wherein said SARMs are complementary to, and can base pair with, 15-20 consecutive nucleotides of a target RNA, which target RNA is transcribed from a gene that is silenced when said SRMs are present in a cell containing said gene, and said SSRMs correspond to the target RNA;   wherein said gene is endogenous to an organism selected from the group consisting of a plant, a mammal, an avian organism, a reptile, an insect, and a protozoan, or said target RNA is generated by a pathogen.   
     
     
         14 . A method of silencing a gene in cells which method comprises introducing into said cells an effective amount of the composition of  claim 13 ,
 whereby said gene is silenced.   
     
     
         15 . The method of  claim 14 , wherein the cells are contained in an organism and said introducing comprises administering said SRMs to the organism. 
     
     
         16 . Cells prepared by the method of  claim 14 . 
     
     
         17 . A non-human organism prepared by the method of  claim 15 . 
     
     
         18 . An improved composition for introduction into a cell to effect gene silencing, which composition comprises at least one vector which, when introduced into a cell, produces short antisense RNA molecules (SARMs);
 wherein said SARMs are complementary to, and can base pair with, 15-20 consecutive nucleotides of a target RNA;   the improvement comprising including in said at least one vector sequences such that short sense RNA molecules (SSRMs) are also produced, wherein said SSRMs and said SSRMs are complementary to said SARMs; and   which target RNA is transcribed from a gene that is silenced when said SARMs and SSRMs are present in a cell containing said gene,   wherein said gene is endogenous to an organism selected from the group consisting of a plant, a mammal, an avian organism, a reptile, an insect, and a protozoan, or   said target RNA is generated by a pathogen.   
     
     
         19 . A method of silencing a gene in cells which method comprises introducing into said cells an effective amount of the composition of  claim 18 ,
 whereby said gene is silenced.   
     
     
         20 . The method of  claim 19 , wherein the cells are contained in an organism and said introducing comprises administering said SRMs to the organism. 
     
     
         21 . Cells prepared by the method of  claim 19 . 
     
     
         22 . A non-human organism prepared by the method of  claim 20 .