Micro-RNA: A New Kind of Gene Regulators

A group of small RNA molecules, distinct from but related to siRNAs (small interference RNAs) have been identified in a variety of organisms. These small RNAs, called microRNAs (miRNAs), are endogenously encoded approximately 20–24 nt long single-stranded RNAs. They are generally expressed in a highly tissue- or developmental-stage-specific fashion and are post-transcriptional regulator of gene expression in animals and plants. This article summarizes the character, mechanism and analysis method about miRNAs. The current view that miRNAs represent a newly discovered, hidden layer of gene regulation has resulted in high interest among researchers in the discovery of miRNAs, their targets, expression mechanism of action and analysis methods.