Genetically encoded tools for RNA imaging in living cells.

RNA imaging probes help us investigate how transport and dynamics of RNA contribute to subcellular RNA localization or regulation of gene expression. Out of the plethora of strategies that have been developed to image RNA in living cells, genetically encoded probes are interesting because they can be produced by the cellular machinery and do not require transfection of the cell. These probes can be grouped into fluorophore-binding aptamers and RNA-binding proteins fused to whole or split fluorescent proteins. In this review, we highlight recent developments in the field of genetically encoded probes for RNA imaging and discuss the strengths and limitations of the different approaches.