Engineering Elements for Gene Silencing: The Artificial MicroRNAs Technology
Small RNA (sRNA)-mediated gene silencing constitutes a powerful tool for the molecular characterization of a given gene. The RNAi technology has been largely used for this purpose. This approach is based on the cloning of an inverted repeated fragment of the gene to be silenced. Even when this approach produces a strong repression of the target gene it also involves the production of multiple small RNAs species that can easily lead to off targeting. Taking advantage of the latest insights into the new post-biogenesis layer of regulation in microRNA (miRNA) activity, it is possible to overcome the above-mentioned limitation. Artificial microRNAs (amiRNAs) are 21mer small RNAs, which can be genetically engineered and they function to specifically silence single or multiple genes of interest. Since generally just one miRNA molecule is generated from each precursor, the specificity of this technology is much higher than longer inverted repeats. Application of this technology results in highly specific mRNA downregulation by computationally designed sequences programmed to target one or a set of custom-selected transcripts.
Key wordsMicroRNA Small RNA attenuation Specific gene downregulation Gene silencing
The authors would like to thank Proffesor Detlef Weigel and the microRNA team at his lab for continuous and helpful discussion and Beth Rowans for manuscript comments and text editing. Authors are supported by the European Community FP6 IP SIROCCO (contract LSHG-CT-2006-037900) and by the Max Planck Society.
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