Abstract: The invention is directed towards constructs for RNAi techniques. The invention provides a ribonucleic acid (RNA) for use as interfering RNA in gene silencing techniques to silence a target gene comprising in a 5? to 3? direction at least a first effector sequence, a second effector sequence, a sequence substantially complementary to the second effector sequence and a sequence substantially complementary to the first effector sequence, wherein the complementary sequences are capable of forming double stranded regions with their respective effector sequences and wherein at least one of these sequences is substantially identical to the predicted transcript of a region of the target gene, and a nucleic acid construct encoding such an RNA.

Abstract: The present invention relates generally to synthetic genes for modifying endogenous gene expression in a cell, tissue or organ of a transgenic organism, in particular a transgenic animal or plant. More particularly, the present invention provides novel synthetic genes and genetic constructs which are capable of repressing delaying or otherwise reducing the expression of an endogenous gene or a target gene in an organism when introduced thereto.