Abstract: The present invention relates to a Drosophila in vitro system which was used to demonstrate that dsRNA is processed to RNA segments 21-23 nucleotides (nt) in length. Furthermore, when these 21-23 nt fragments are purified and added back to Drosophila extracts, they mediate RNA interference in the absence of long dsRNA. Thus, these 21-23 nt fragments are the sequence-specific mediators of RNA degradation. A molecular signal, which may be their specific length, must be present in these 21-23 nt fragments to recruit cellular factors involved in RNAi. This present invention encompasses these 21-23 nt fragments and their use for specifically inactivating gene function. The use of these fragments (or chemically synthesized oligonucleotides of the same or similar nature) enables the targeting of specific mRNAs for degradation in mammalian cells, where the use of long dsRNAs to elicit RNAi is usually not practical, presumably because of the deleterious effects of the interferon response.

Abstract: The present invention relates to a Drosophila in vitro system which was used to demonstrate that dsRNA is processed to RNA segments 21-23 nucleotides (nt) in length. Furthermore, when these 21-23 nt fragments are purified and added back to Drosophila extracts, they mediate RNA interference in the absence of long dsRNA. Thus, these 21-23 nt fragments are the sequence-specific mediators of RNA degradation. A molecular signal, which may be their specific length, must be present in these 21-23 nt fragments to recruit cellular factors involved in RNAi. This present invention encompasses these 21-23 nt fragments and their use for specifically inactivating gene function. The use of these fragments (or chemically synthesized oligonucleotides of the same or similar nature) enables the targeting of specific mRNAs for degradation in mammalian cells, where the use of long dsRNAs to elicit RNAi is usually not practical, presumably because of the deleterious effects of the interferon response.

Abstract: In one aspect, the invention relates to a method for fixing a short nucleic acid in a biological sample. In another aspect, the invention relates to a method for detecting a target short nucleic acid in a biological sample. The method includes contacting the biological sample with an aldehyde-containing fixative, and subsequently contacting the sample with a water-soluble carbodiimide. In a further aspect, the invention relates to a kit for fixing a short nucleic acid in a biological sample. The kit includes a support substrate for holding the sample; an aldehyde-containing fixative; and a water-soluble carbodiimide.

Abstract: The invention provides a novel truncated mutated T4 RNA ligase 2. In addition, methods are provided for ligating pre-adenlylated donor molecules to the 3? hydroxyl group of RNA in the absence of ATP using the ligase.

Abstract: Double-stranded RNA (dsRNA) induces sequence-specific post-transcriptional gene silencing in many organisms by a process known as RNA interference (RNAi). Using a Drosophila in vitro system, we demonstrate that 19-23 nt short RNA fragments are the sequence-specific mediators of RNAi. The short interfering RNAs (siRNAs) are generated by an RNase III-like processing reaction from long dsRNA. Chemically synthesized siRNA duplexes with overhanging 3? ends mediate efficient target RNA cleavage in the lysate, and the cleavage site is located near the center of the region spanned by the guiding siRNA. Furthermore, we provide evidence that the direction of dsRNA processing determines whether sense or antisense target RNA can be cleaved by the produced siRNP complex.

Abstract: Double-stranded RNA (dsRNA) induces sequence-specific post-transcriptional gene silencing in many organisms by a process known as RNA interference (RNAi). Using a Drosophila in vitro system, we demonstrate that 19-23 nt short RNA fragments are the sequence-specific mediators of RNAi. The short interfering RNAs (siRNAs) are generated by an RNase III-like processing reaction from long dsRNA. Chemically synthesized siRNA duplexes with overhanging 3? ends mediate efficient target RNA cleavage in the lysate, and the cleavage site is located near the center of the region spanned by the guiding siRNA. Furthermore, we provide evidence that the direction of dsRNA processing determines whether sense or antisense target RNA can be cleaved by the produced siRNP complex.

Abstract: Double-stranded RNA (dsRNA) induces sequence-specific post-transcriptional gene silencing in many organisms by a process known as RNA interference (RNAi). Using a Drosophila in vitro system, we demonstrate that 19-23 nt short RNA fragments are the sequence-specific mediators of RNAi. The short interfering RNAs (siRNAs) are generated by an RNase III-like processing reaction from long dsRNA. Chemically synthesized siRNA duplexes with overhanging 3? ends mediate efficient target RNA cleavage in the lysate, and the cleavage site is located near the center of the region spanned by the guiding siRNA. Furthermore, we provide evidence that the direction of dsRNA processing determines whether sense or antisense target RNA can be cleaved by the produced siRNP complex.

Abstract: The invention relates to vectors for the inducible expression of RNA molecules in eukaryotic, particularly mam

Abstract: The invention relates to isolated DNA or RNA molecules comprising at least ten contiguous bases having a sequence in a microRNA shown in SEQ ID NOs: 1-94; 281-374; 467-481; 497-522; or 549, except that up to thirty percent of the bases may be wobble bases, and up to 10% of the contiguous bases may be non-complementary. The invention further relates to modified single stranded microRNA molecules, isolated single stranded anti-microRNA molecules and isolated microRNP molecules. In another embodiment, the invention relates to a method for inhibiting microRNP activity in a cell.

Abstract: The present invention relates to sequence and structural features of single-stranded (ss)RNA molecules required to mediate target-specific nucleic acid modifications by RNA-interference (RNAi), such as target mRNA degradation and/or DNA methylation.

Abstract: The invention relates to isolated DNA or RNA molecules comprising at least ten contiguous bases having a sequence in a microRNA shown in SEQ ID NOs: 1-94; 281-374; 467-481; 497-522; or 549, except that up to thirty percent of the bases may be wobble bases, and up to 10% of the contiguous bases may be non-complementary. The invention further relates to modified single stranded microRNA molecules, isolated single stranded anti-microRNA molecules and isolated microRNP molecules. In another embodiment, the invention relates to a method for inhibiting microRNP activity in a cell.

Abstract: In Caenorhabditis elegans, lin-4 and let-7 enclode 22- and 21-nucleotide RNAs, respectively, that function as key regulators of developmental timing. Because the appearance of these short RNAs is regulated during development, they are also referred to as “small temporal RNAs” (stRNAs). We show that many more 21- and 22-nt expressed RNAs, termed microRNAs, (miRNAs), exist in invertebrates and vertebrates, and that some of these novel RNAs, similar to let-7 stRAN, are also highly conserved. This suggests that sequence-specific post-transcriptional regulatory mechanisms mediated by small RNAs are more general than previously appreciated.

Abstract: In Caenorhabditis elegans, lin-4 and let-7 enclode 22- and 21-nucleotide RNAs, respectively, that function as key regulators of developmental timing. Because the appearance of these short RNAs is regulated during development, they are also referred to as “small temporal RNAs” (stRNAs). We show that many more 21- and 22-nt expressed RNAs, termed microRNAs, (miRNAs), exist in invertebrates and vertebrates, and that some of these novel RNAs, similar to let-7 stRAN, are also highly conserved. This suggests that sequence-specific post-transcriptional regulatory mechanisms mediated by small RNAs are more general than previously appreciated.

Abstract: The invention relates to vectors for the inducible expression of RNA molecules in eukaryotic, particularly mammalian cells and transgenic animals.

Abstract: In Caenorhabditis elegans, lin-4 and let-7 enclode 22- and 21 -nucleotide RNAs, respectively, that function as key regulators of developmental timing. Because the appearance of these short RNAs is regulated during development, they are also referred to as “small temporal RNAs” (stRNAs). We show that many more 21- and 22-nt expressed RNAs, termed microRNAs, (miRNAs), exist in invertebrates and vertebrates, and that some of these novel RNAs, similar to let-7 stRAN, are also highly conserved. This suggests that sequence-specific post-transcriptional regulatory mechanisms mediated by small RNAs are more general than previously appreciated.

Abstract: The present invention relates to a Drosophila in vitro system which was used to demonstrate that dsRNA is processed to RNA segments 21-23 nucleotides (nt) in length. Furthermore, when these 21-23 nt fragments are purified and added back to Drosophila extracts, they mediate RNA interference in the absence of long dsRNA. Thus, these 21-23 nt fragments are the sequence-specific mediators of RNA degradation. A molecular signal, which may be their specific length, must be present in these 21-23 nt fragments to recruit cellular factors involved in RNAi. This present invention encompasses these 21-23 nt fragments and their use for specifically inactivating gene function. The use of these fragments (or chemically synthesized oligonucleotides of the same or similar nature) enables the targeting of specific mRNAs for degradation in mammalian cells, where the use of long dsRNAs to elicit RNAi is usually not practical, presumably because of the deleterious effects of the interferon response.

Abstract: The invention relates to isolated anti-microRNA molecules. In another embodiment, the invention relates to an isolated microRNA molecule. In yet another embodiment, the invention provides a method for inhibiting microRNP activity in a cell.

Abstract: The invention relates to isolated nucleic acid molecules comprising the sequence of a human cytomegalovirus microRNA. In another embodiment, the invention relates to single stranded DNA virus microRNA molecules comprising the sequence of a human cytomegalovirus microRNA. The invention also relates to the anti-DNA virus microRNA molecules.

Abstract: The present invention relates to a Drosophila in vitro system which was used to demonstrate that dsRNA is processed to RNA segments 21-23 nucleotides (nt) in length. Furthermore, when these 21-23 nt fragments are purified and added back to Drosophila extracts, they mediate RNA interference in the absence of long dsRNA. Thus, these 21-23 nt fragments are the sequence-specific mediators of RNA degradation. A molecular signal, which may be their specific length, must be present in these 21-23 nt fragments to recruit cellular factors involved in RNAi. This present invention encompasses these 21-23 nt fragments and their use for specifically inactivating gene function. The use of these fragments (or chemically synthesized oligonucleotides of the same or similar nature) enables the targeting of specific mRNAs for degradation in mammalian cells, where the use of long dsRNAs to elicit RNAi is usually not practical, presumably because of the deleterious effects of the interferon response.

Abstract: The present invention relates to sequence and structural features of single-stranded (ss) RNA molecules required to mediate target-specific nucleic acid modifications by RNA-interference (RNAi), such as target mRNA degradation and/or DNA methylation.