Exploring microRNA functions in zebrafish

The microRNA (miRNA) pathway and the phenomenon of RNA interference (RNAi) have similar mechanisms and depend partly on the same cellular factors. Humans may have more than 1000 different miRNAs, which are essential regulators of gene expression in many biological processes. RNAi-based techniques have become important tools in biomedical research and have great potential for use in disease therapy. Zebrafish (Danio rerio) provide several advantages for the study of miRNA functions. However, reliable RNAi-based gene silencing techniques have not been established for this important vertebrate model. In this article, we describe the highly efficient in vivo assays used to study miRNA functions in zebrafish and how these experimental approaches have uncovered new regulatory mechanisms in vertebrates. This research has also provided information that explains why RNAi techniques have been unsuccessful in zebrafish.