( Illumination of a Critical Regulation ...)Getting Started with MicroRNA Research

MicroRNAs (miRNAs) are a recently identified class of cellular RNAs that regulate protein expression at the translational level. The active, mature miRNAs are 1724 base, single-stranded RNA molecules expressed in eukaryotic cells and are known to affect the translation or stability of target messenger RNAs. Each microRNA is believed to regulate multiple genes, with predictions that greater than one third of all human genes may be regulated by miRNA molecules [1].

Genes encoding approximately 230 miRNAs have already been identified in mammals [2]. Interestingly, more than 90% of the miRNAs are completely conserved among species, suggesting that these molecules are sensitive to small sequence changes and are potentially under extraordinary selection pressure. Here, we provide a general overview for analyzing miRNAs and describe some of the specialized tools that can help assess miRNA expression, function, and targets.

MicroRNAs (miRNAs) are highly conserved regulatory molecules expressed in eukaryotic cells. Data recently published in Cell suggest that the expression of certain genes can be more dependent on the levels of regulatory miRNAs than on the levels of messenger RNAs that encode the proteins [3]. MicroRNAs function through a mechanism similar to short interfering RNAs (siRNAs) in that both of these types of small, single-stranded RNA molecules target specific messenger RNA tra
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