Abstract: Methods and means are provided for reducing the phenotypic expression of a nucleic acid of interest in eukaryotic cells by providing aberrant, preferably unpolyadenylated, target-specific RNA to the nucleus of the host cell. Preferably, the unpolyadenylated, target-specific RNA is provided by transcription of a chimeric gene comprising a promoter and a DNA region encoding the target-specific RNA.

Abstract: Methods and means are provided for reducing the phenotypic expression of a nucleic acid of interest in eukaryotic cells by providing aberrant, preferably unpolyadenylated, target-specific RNA to the nucleus of the host cell. Preferably, the unpolyadenylated, target-specific RNA is provided by transcription of a chimeric gene comprising a promoter and a DNA region encoding the target-specific RNA.

Abstract: Provided are methods and means to obtain improved gene silencing of target nucleic acids whereby at least two inhibitory RNA molecules are provided which are targeted to the same nucleic acid, but which are processed into short interfering RNA molecules through different processing pathways. Also provided are methods and means to obtain improved gene silencing of target nucleic acids whereby at least two inhibitory RNA molecules are provided which are targeted to different nucleic acids, but which are processed into short interfering RNA molecules through different processing pathways.

Abstract: Provided are methods and means to obtain improved gene silencing of target nucleic acids whereby at least two inhibitory RNA molecules are provided which are targeted to the same nucleic acid, but which are processed into short interfering RNA molecules through different processing pathways. Also provided are methods and means to obtain improved gene silencing of target nucleic acids whereby at least two inhibitory RNA molecules are provided which are targeted to different nucleic acids, but which are processed into short interfering RNA molecules through different processing pathways.

Abstract: Methods and means are provided for monitoring and modulating reduction of gene expression in eukaryotic organisms, using double stranded RNA comprising, in addition to the dsRNA region comprising nucleotide sequences homologous to the target gene, additional dsRNA regions designed to down regulate a second gene or which are unrelated to the target gene.

Abstract: Provided are methods and means to obtain improved gene silencing of target nucleic acids whereby at least two inhibitory RNA molecules are provided which are targeted to the same nucleic acid, but which are processed into short interfering RNA molecules through different processing pathways. Also provided are methods and means to obtain improved gene silencing of target nucleic acids whereby at least two inhibitory RNA molecules are provided which are targeted to different nucleic acids, but which are processed into short interfering RNA molecules through different processing pathways.

Abstract: Methods and means are provided to modulate gene silencing in eukaryotes through the alteration of the functional level of particular DICER or DICER like proteins. Also provided are methods and means to modulate post-transcriptional gene silencing in eukaryotes through the alteration of the functional level of proteins involved in transcriptional silencing of the silencing RNA encoding genes.

Abstract: Methods and means for efficiently downregulating the expression of any gene of interest in eukaryotic cells and organisms are provided. To this end, the invention provides modified antisense and sense RNA molecules, chimeric genes encoding such modified antisense or sense RNA molecules and eukaryotic organisms such as plants, animals or fungi, yeast or molds, comprising the modified antisense and/or sense RNA molecules or the encoding chimeric genes.

Abstract: Methods and means for efficiently downregulating the expression of any gene of interest in eukaryotic cells and organisms are provided. To this end, the invention provides modified antisense and sense RNA molecules, chimeric genes encoding such modified antisense or sense RNA molecules and eukaryotic organisms such as plants, animals or fungi, yeast or molds, comprising the modified antisense and/or sense RNA molecules or the encoding chimeric genes.

Abstract: Methods and means are provided for reducing the phenotypic expression of a nucleic acid of interest in eucaryotic cells, particularly in plant cells, by introducing chimeric genes encoding sense and antisense RNA molecules directed towards the target nucleic acid, which are capable of forming a double stranded RNA region by base-pairing between the regions with sense and antisense nucleotide sequence or by introducing the RNA molecules themselves. Preferably, the RNA molecules comprises simultaneously both sense and antisense nucleotide sequence.

Abstract: Methods and means are provided for reducing the phenotypic expression of a nucleic acid of interest in eucaryotic cells, particularly in plant cells, by introducing chimeric genes encoding sense and antisense RNA molecules directed towards the target nucleic acid, which are capable of forming a double stranded RNA region by base-pairing between the regions with sense and antisense nucleotide sequence or by introducing the RNA molecules themselves. Preferably, the RNA molecules comprises simultaneously both sense and antisense nucleotide sequence.

Abstract: Methods and means are provided for reducing the phenotypic expression of a nucleic acid of interest in eukaryotic cells, particularly in plant cells, by providing aberrant, preferably unpolyadenylated, target-specific RNA to the nucleus of the host cell. Preferably, the unpolyadenylated target-specific RNA is provided by transcription of a chimeric gene comprising a promoter, a DNA region encoding the target-specific RNA, a self-splicing ribozyme and a DNA region involved in 3? end formation and polyadenylation.

Abstract: The current invention provides methods to silence insect genes by using unpackaged dsRNA or siRNA, in one embodiment such dsRNA or siRNA is present in plant vascular tissue, preferably phloem, more particularly phloem sap, and the insect is a plant sap-sucking insect. Also provided are DNA sequences which when transcribed yield a double-stranded RNA molecule capable of reducing the expression of an essential gene of a plant sap-sucking insect, methods of using such DNA sequences and plants or plant cells transformed with such DNA sequences. Also provided is the use of cationic oligopeptides that facilitate the entry of dsRNA or siRNA molecules in insect cells, such as plant sap-sucking insect cells.

Abstract: Methods and means are provided for reducing the phenotypic expression of a nucleic acid of interest in eucaryotic cells, particularly in plant cells, by introducing chimeric genes encoding sense and antisense RNA molecules directed towards the target nucleic acid, which are capable of forming a double stranded RNA region by base-pairing between the regions with sense and antisense nucleotide sequence or by introducing the RNA molecules themselves. Preferably, the RNA molecules comprises simultaneously both sense and antisense nucleotide sequence.

Abstract: Methods and means are provided for reducing the phenotypic expression of a nucleic acid of interest in eukaryotic cells, particularly in plant cells, by providing aberrant, preferably unpolyadenylated, target-specific RNA to the nucleus of the host cell. Preferably, the unpolyadenylated target-specifc RNA is provided by transcription of a chimeric gene comprising a promoter, a DNA region encoding the target-specific RNA, a self-splicing ribozyme and a DNA region involved in 3? end formation and polyadenylation.

Abstract: Methods and means are provided for producing chimeric nucleic acid constructs capable of producing dsRNA for silencing target nucleic acid sequences of interest using recombinational cloning.

Abstract: Methods and means are provided for producing chimeric nucleic acid constructs capable of producing dsRNA for silencing target nucleic acid sequences of interest using recombinational cloning.

Abstract: The invention relates to methods for producing transgenic cereal plants resistant to Barley Yellow Dwarf Virus, particularly in the presence of co-infecting Cereal Yellow Dwarf Virus, by stably integrating into the cells of the transgenic plant a chimeric gene comprising a DNA region operably linked to plant expressible promoter in such a way that the RNA molecule may be transcribed from the DNA region, the RNA molecule comprising both sense and antisense RNA capable of pairing and forming a double stranded RNA molecule or hairpin RNA.

Abstract: Methods and means for efficiently downregulating the expression of any gene of interest in eukaryotic cells and organisms are provided. To this end, the invention provides modified antisense and sense RNA molecules, chimeric genes encoding such modified antisense or sense RNA molecules and eukaryotic organisms such as plants, animals or fungi, yeast or molds, comprising the modified antisense and/or sense RNA molecules or the encoding chimeric genes.

Abstract: Methods and means are provided for monitoring and modulating reduction of gene expression in eukaryotic organisms, using double-stranded RNA comprising, in addition to the dsRNA region comprising nucleotide sequences homologous to the target gene, additional dsRNA regions designed to down regulate a second gene or which are unrelated to the target gene.