Until recently it was thought that the majority of regulation was carried out by proteins, and that the DNA between protein-coding genes was nothing other than junk DNA. However this view has changed with the discovery of a new class of gene regulators called small RNAs. These molecules constitute an RNA-centric layer of control whose enormity has only become apparent in the last five years and may provide part of the regulatory requirements needed for the level of complexity observed in higher eukaryotes.
The lab focuses on one type of small RNA known as microRNAs (miRNAs), many of which have been shown to play pivotal roles in many developmental and physiological processes, in both plants and animals. MiRNA genes encode a transcript that forms an extensive secondary structure known as a stem-loop (Fig. 1A). This stem-loop is then processed into a small 21 nucleotide molecule (Fig. 1B) known as the ‘mature’ miRNA. This miRNA then guides the RNAi silencing machinery to complementary mRNA molecules, which results in the repression of those targeted mRNAs, hence silencing gene expression.
