Abstract: Disclosed are a variety of methods for achieving enhanced expression from a target nucleotide sequence in a plant e.g. comprising the step of transiently introducing into a tissue of a plant (e.g. a leaf) a first nucleic acid comprising the target nucleotide sequence and a second nucleic acid encoding a Post Transcriptional Gene Silencing (PTGS) suppressor protein (preferably of viral or plant origin), wherein the first and second nucleic acids are comprised within a single binary vector, construct, or the first and second nucleic acid sequences are comprised within a first binary vector and a second binary vector construct respectively. The plant tissue may then be harvested for the protein. Such methods can give much higher levels of gene expression than are obtainable using stable transgenes, or certain replicating vectors.

Abstract: Methods and compositions are provided for reducing the level of expression of a target polynucleotide in an organism. The methods and compositions selectively silence the target polynucleotide through the expression of a chimeric polynucleotide comprising the target for a sRNA (the trigger sequence) operably linked to a sequence corresponding to all or part of the gene or genes to be silenced. In this manner, the final target of silencing is an endogenous gene in the organism in which the chimeric polynucleotide is expressed. In a further embodiment, the miRNA target is that of a heterologous miRNA or siRNA, the latter of which is coexpressed in the cells at the appropriate developmental stage to provide silencing of the final target when and where desired. In a further embodiment, the final target may be a gene in a second organism, such as a plant pest, that feeds upon the organism containing the chimeric gene or genes.

Abstract: Provided are methods of screening for the occurrence of gene silencing (e.g. post transcriptional gene silencing) in an organism (e.g. a plant or animal), which method comprises the steps of: (i) obtaining a sample of material from said organism, (ii) producing a nucleic acid extract from said sample, (iii) analysing said extract such as to determine the presence or absence of short RNA molecules which are approximately 25 nucleotides in length (SRMs) in said nucleic extract, (iv) correlating the presence of said SRMs in the extract with the occurrence of gene silencing in said organism. The SRMs are preferably short anti-sense RNA molecules (SARMs). Also provided are associated methods for detecting the silencing of a target gene in an organism.

Abstract: Provided are methods of silencing a target gene in an organism, which methods comprises the steps of: (a) providing a recombinant DNA construct including an expression cassette comprising: (i) a promoter, operably linked to, (ii) a chimeric nucleotide sequence encoding all or part of the target gene and a transgene, (b) transforming the organism with said DNA construct such that the expression cassette is inserted into the genome, and (c) initiating post transcriptional gene silencing (PTGS) of said transgene in said organism, whereby initiation of PTGS of the transgene causes silencing of the target gene in the organism. The methods are based on a phenomenon termed “spreading” whereby PTGS of the transgene can be used to spread in trans to silence, for example, endogenous target genes in the same genetic background as the chimeric gene to give consistent, maintained, silencing thereof. Also provided are related materials (e.g. recombinant constructs) and uses and methods based on these.

Abstract: Provided are methods of screening for the occurrence of gene silencing (e.g. post transcriptional gene silencing) in an organism (e.g. a plant or animal), which method comprises the steps of; (i) obtaining a sample of material from said organism, (ii) producing a nucleic acid extract from said sample, (iii) analysing said extract such as to determine the presence or absence of short RNA molecules which are approximately 25 nucleotides in length (SRMs) in said nucleic extract, (iv) correlating the presence of said SRMs in the extract with the occurrence of gene silencing in said organism. The SRMs are preferably short anti-sense RNA molecules (SARMs). Also provided are associated methods for detecting the silencing of a target gene in an organism.

Abstract: Provided are methods of screening for the occurrence of gene silencing (e.g. post transcriptional gene silencing) in an organism (e.g. a plant or animal), which method comprises the steps of; (i) obtaining a sample of material from said organism, (ii) producing a nucleic acid extract from said sample, (iii) analysing said extract such as to determine the presence or absence of short RNA molecules which are approximately 25 nucleotides in length (SRMs) in said nucleic extract, (iv) correlating the presence of said SRMs in the extract with the occurrence of gene silencing in said organism. The SRMs are preferably short anti-sense RNA molecules (SARMs). Also provided are associated methods for detecting the silencing of a target gene in an organism.

Abstract: Provided are methods of screening for the occurrence of gene silencing (e.g. post transcriptional gene silencing) in an organism (e.g. a plant or animal), which method comprises the steps of: (i) obtaining a sample of material from said organism, (ii) producing a nucleic acid extract from said sample, (iii) analysing said extract such as to determine the presence or absence of short RNA molecules which are approximately 25 nucleotides in length (SRMs) in said nucleic extract, (iv) correlating the presence of said SRMs in the extract with the occurrence of gene silencing in said organism. The SRMs are preferably short anti-sense RNA molecules (SARMs). Also provided are associated methods for detecting the silencing of a target gene in an organism.

Abstract: Provided are methods of screening for the occurrence of gene silencing (e.g. post transcriptional gene silencing) in an organism (e.g. a plant or animal), which method comprises the steps of; (i) obtaining a sample of material from said organism, (ii) producing a nucleic acid extract from said sample, (iii) analysing said extract such as to determine the presence or absence of short RNA molecules which are approximately 25 nucleotides in length (SRMs) in said nucleic extract, (iv) correlating the presence of said SRMs in the extract with the occurrence of gene silencing in said organism. The SRMs are preferably short anti-sense RNA molecules (SARMs). Also provided are associated methods for detecting the silencing of a target gene in an organism.