New Technique Involving Roche´s LightCycler^® 480 Instrument Enables Efficient and Economic Studies on RNA Editing

Current research in the area of RNA editing is limited by the lack of cheap, effective approaches for screening for new editing sites or for mutants affected in the editing process. Previously used methods to study RNA editing, such as cDNA sequencing, primer extension or pyrosequencing are either too expensive, not sensitive enough, or too labor intensive for high-throughput screens.

Now, a one-step, high-throughput method using High Resolution Melting on the LightCycler^® 480 System is described (see Chateigner-Boutin, A-L, Small, I (2007) Nucleic Acids Research, 1–8, doi:10.1093/nar/gkm640). It allows both the scanning of transcripts for new editing sites (without any prior knowledge of their nature or location) and the quantification of editing. The method, originally designed to detect DNA mutations and genotype individuals in clinical research and diagnostics, can be simply adapted to research on RNA editing. This new approach can be simply and directly applied to samples from any organism, so this breakthrough should stimulate research in many laboratories.

RNA editing is reported in a wide range of organisms from viruses to mammals and plants where it has different functions such as regulating gene expression, increasing protein diversity or reversing the effect of mutations in the genome. It is defined as a site-specific modification of RNA molecules, occurring by nucleotide insertion/deletion, substitution or modification. In many cases, RNA editing is essential for correct production of the protein encoded, e.g., in humans, where this process is essential for the absorption of dietary fats in small intestine by producing the lipid-carrying protein apolipoprotein B48. In other cases, RNA editing modulates the functional properties of the encoded protein as in the case of the glutamate and serotonin receptors in the central nervous system.